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Cantelli V, Meirelles MT, Della Bona A. Fatigue methods for evaluating translucent dental zirconia. J Dent 2024; 148:105242. [PMID: 39009334 DOI: 10.1016/j.jdent.2024.105242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2024] [Revised: 07/11/2024] [Accepted: 07/12/2024] [Indexed: 07/17/2024] Open
Abstract
OBJECTIVE To investigate fatigue methods for the evaluation of translucent zirconia and to associate in vitro failures with clinically reported ones. DATA Studies published in English that used fatigue tests on dental translucent zirconia. SOURCES Two databases (MEDLINE/PubMed and Scopus) were electronically searched without any restriction on year of publication. STUDY SELECTION A total of 4555 studies were identified. After removal of duplicates (78) and irrelevant articles (4316) that did not meet the inclusion criteria, 161 articles were considered eligible based on their titles and abstracts. These articles were fully read, leading to the inclusion of 41 studies in the review. RESULTS The most widely used fatigue method for evaluation of translucent zirconia was step-stress (18 articles), followed by staircase (seven articles), and step-wise (two articles). Most studies had been conducted in a wet environment with the use of a stainless steel piston to apply load to cemented structures on a dentin-like substrate. Most fracture analyses indicated the fracture originated on the cementation or contact surface where the load was applied. Moreover, studies that utilized anatomical structures (dental crowns) reported fractures starting at the cervical margin of the crowns. CONCLUSION Most studies used the step-stress method. Only three studies reported failures similar to those found in clinical trials that used translucent zirconia restorations. CLINICAL SIGNIFICANCE The study findings can assist on correlating clinical failures to the ones observed in vitro.
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Affiliation(s)
- Viviane Cantelli
- Post-graduate Program in Dentistry, School of Dentistry, University of Passo Fundo, Passo Fundo, RS, Brazil
| | - Marcelo Tapparo Meirelles
- Graduate Program in Dentistry, School of Dentistry, University of Passo Fundo, Passo Fundo, RS, Brazil
| | - Alvaro Della Bona
- Post-graduate Program in Dentistry, School of Dentistry, University of Passo Fundo, Passo Fundo, RS, Brazil.
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Crins LAMJ, Opdam NJM, Huysmans MCDNJM, Zhang Y, Loomans BAC. An in vitro evaluation of the fatigue behavior of resin composite materials as part of a translational research cycle. Dent Mater 2024; 40:1409-1416. [PMID: 38926014 PMCID: PMC11330355 DOI: 10.1016/j.dental.2024.06.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 06/05/2024] [Indexed: 06/28/2024]
Abstract
PURPOSE This study aimed to reproduce and translate clinical presentations in an in vitro set-up and evaluate laboratory outcomes of mechanical properties (flexural strength, fatigue resistance, wear resistance) and link them to the clinical outcomes of the employed materials in the Radboud Tooth Wear Project (RTWP). MATERIALS AND METHODS Four dental resin composites were selected. 30 discs (Ø12.0 mm, 1.2 mm thick) were fabricated for each of Clearfil TM AP-X (AP), Filtek TM Supreme XTE (FS), Estenia TM C&B (ES), and Lava Ultimate (LU). Cyclic loading (200 N, 2 Hz frequency) was applied concentrically to 15 specimens per group with a spherical steatite indenter (r = 3.18 mm) in water in a contact-load-slide-liftoff motion (105 cycles). The wear scar was analysed using profilometry and the volume loss was digitally computed. Finally, all specimens were loaded (fatigued specimens with their worn surface loaded in tension) until fracture in a biaxial flexure apparatus. The differences in volume loss and flexural strength were determined using regression analysis. RESULTS Compared to AP and FS, ES and LU showed a significantly lower volume loss (p < 0.05). Non-fatigued ES specimens had a similar flexural strength compared to nonfatigued AP, while non-fatigued FS and LU specimens had a lower flexural strength (p < 0.001; 95 %CI: -80.0 - 51.8). The fatigue test resulted in a significant decrease of the flexural strength of ES specimens, only (p < 0.001; 95 %CI: -96.1 - -54.6). CLINICAL RELEVANCE These outcomes concur with the outcomes of clinical studies on the longevity of these composites in patients with tooth wear. Therefore, the employed laboratory test seems to have the potential to test materials in a clinically relevant way.
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Affiliation(s)
- L A M J Crins
- Radboud University Medical Center, Department of Dentistry, P.O. Box 9101, Nijmegen 6525 EX, the Netherlands.
| | - N J M Opdam
- Radboud University Medical Center, Department of Dentistry, P.O. Box 9101, Nijmegen 6525 EX, the Netherlands
| | - M C D N J M Huysmans
- Radboud University Medical Center, Department of Dentistry, P.O. Box 9101, Nijmegen 6525 EX, the Netherlands
| | - Y Zhang
- Department of Preventive & Restorative Sciences, School of Dental Medicine, University of Pennsylvania, 109 Levy Buidling, Philadelphia, USA
| | - B A C Loomans
- Radboud University Medical Center, Department of Dentistry, P.O. Box 9101, Nijmegen 6525 EX, the Netherlands
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Li Q, Zhan N, Ng T, Swain MV, Wan B, Jian Y, Wang X, Zhao K. The influence of hygroscopic expansion of resin supporting dies on the fracture resistance of ceramic restorations during thermal cycling. Dent Mater 2024; 40:1231-1243. [PMID: 38853105 DOI: 10.1016/j.dental.2024.06.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 06/05/2024] [Indexed: 06/11/2024]
Abstract
OBJECTIVES To evaluate the hygroscopic expansion characterization of resin composite dies during thermal cycling, and their influence on the fracture resistance of dental ceramic materials as well as the effect of pre-immersion on these measurements. METHODS Disc-shaped specimens (φ = 15.0 mm, h = 1.2 mm) and anatomical crown dies of four resin composites (epoxy, Z350, P60, G10) were fabricated. Disc-shaped samples were continuously soaked in distilled water and the volume expansion was measured at different time point by Archimedes method. Disc-shaped samples were pre-immersed for 0, 7, or 30 days, elastic modulus and hardness were measured using Nanoindentation test; thermal cycling (TC) test was performed (5 °C-55 °C, 104 cycles), and volume expansion during TC was measured. Four kinds of resin die with pre-immersion for 0, 7, or 30 days were cemented to 5Y-Z crown, or epoxy dies without pre-immersion were cemented to 5Y-Z, 3Y-Z and lithium disilicate glass (LDG) crowns, and load-to-failure testing was performed before and after TC. Finite element analysis (FEA) and fractography analysis were also conducted. RESULTS The hygroscopic expansion was in the order: epoxy > Z350 > P60 > G10. Except for G10, the other three resin composites exhibited different degrees of hygroscopic expansion during TC. Only the elastic modulus and hardness of epoxy decreased after water storage. However, only the fracture loads of 5Y-Z and LDG crowns supported by epoxy dies were significantly decreased after TC. FEA showed a stress concentration at the cervical region of the crown after volume expansion of the die, leading to the increase of the peak stress at the crown during loading. SIGNIFICANCE Only the hygroscopic expansion of epoxy dies caused by TC led to the decrease in the fracture resistance of the 5Y-Z and LDG crown, which may be related to the decrease in the elastic modulus of the epoxy die and the tensile stress caused by it.
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Affiliation(s)
- Qiulan Li
- Hospital of Stomatology, Sun Yat-Sen University, Guangzhou 510055, China; Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510055, China
| | - Ni Zhan
- Hospital of Stomatology, Sun Yat-Sen University, Guangzhou 510055, China; Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510055, China
| | - Takkun Ng
- Hospital of Stomatology, Sun Yat-Sen University, Guangzhou 510055, China; Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510055, China
| | - Michael V Swain
- Don State Technical University, Rostov-on-Don 344000, Russia; AMME, Sydney University, Sydney, Australia
| | - Boyang Wan
- School of Aerospace, Mechanical and Mechatronic Engineering (AMME), The University of Sydney, NSW 2006, Australia
| | - Yutao Jian
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510055, China; Institute of Stomatology, Sun Yat-Sen University, Guangzhou 510055, China.
| | - Xiaodong Wang
- Hospital of Stomatology, Sun Yat-Sen University, Guangzhou 510055, China; Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510055, China.
| | - Ke Zhao
- Hospital of Stomatology, Sun Yat-Sen University, Guangzhou 510055, China; Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510055, China.
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Pilecco RO, da Rosa LS, Baldi A, Machry RV, Tribst JPM, Valandro LF, Kleverlaan CJ, Scotti N, Pereira GKR. How do different intraoral scanners and milling machines affect the fit and fatigue behavior of lithium disilicate and resin composite endocrowns? J Mech Behav Biomed Mater 2024; 155:106557. [PMID: 38657286 DOI: 10.1016/j.jmbbm.2024.106557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 04/03/2024] [Accepted: 04/17/2024] [Indexed: 04/26/2024]
Abstract
The aim of this in vitro study was to evaluate the effect of the combinations of two different intraoral scanners (IOS), two milling machines, and two restorative materials on the marginal/internal fit and fatigue behavior of endocrowns produced by CAD-CAM. Eight groups (n= 10) were considered through the combination of TRIOS 3 (TR) or Primescan (PS) IOS; 4-axes (CR; CEREC MC XL) or 5-axes (PM; PrograMill PM7) milling machines; and lithium disilicate (LD; IPS e.max CAD) or resin composite (RC; Tetric CAD) restorative materials. Specific surface treatments were applied to each material, and the bonding to its corresponding Endocrown-shaped fiberglass-reinforced epoxy resin preparations was performed (Variolink Esthetic DC). Computed microtomography (μCT) was performed to assess the marginal/internal fit, as well as a mechanical fatigue test (20 Hz, initial load = 100 N/5000 cycles; step-size = 50 N/10,000 cycles until a threshold of 1500 N, then, the step-size was increased if needed to 100 N/10,000 cycles until failure or a threshold of 2800 N) to evaluate the restorations long-term behavior. Complementary analysis of the fracture features and surface topography in scanning electron microscopy was performed. Three-way ANOVA and Kaplan-Meier test (α = 0.05) were performed for marginal/internal fit, and fatigue behavior data, respectively. PS scanner, CR milling machine, and RC endocrowns resulted in a better marginal fit compared to their counterparts. Still, the PM machine resulted in a better pulpal space fit compared to the CR milling machine. Regardless of the scanner and milling machine, RC endocrowns exhibited superior fatigue behavior than LD ones. LD endocrowns presented margin chipping regardless of the milling machine used. Despite minor differences in terms of fit, the 'IOS' and 'milling machine' factors did not impair the fatigue behavior of endocrowns. Resin-composite restorations resulted in a higher survival rate compared to glass-ceramic ones, independently of the digital devices used in the workflow.
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Affiliation(s)
- Rafaela Oliveira Pilecco
- Post-Graduate Program in Oral Sciences (Prosthodontics Units), Faculty of Dentistry, Universidade Federal de Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Lucas Saldanha da Rosa
- Post-Graduate Program in Oral Sciences (Prosthodontics Units), Faculty of Dentistry, Universidade Federal de Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Andrea Baldi
- Department of Surgical Sciences, Dental School, University of Turin (UNITO), Turin, Piedmont, Italy.
| | - Renan Vaz Machry
- Post-Graduate Program in Oral Sciences (Prosthodontics Units), Faculty of Dentistry, Universidade Federal de Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - João Paulo Mendes Tribst
- Department of Reconstructive Oral Care, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, North Holland, the Netherlands.
| | - Luiz Felipe Valandro
- Post-Graduate Program in Oral Sciences (Prosthodontics Units), Faculty of Dentistry, Universidade Federal de Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Cornelis Johannes Kleverlaan
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, North Holland, the Netherlands.
| | - Nicola Scotti
- Department of Surgical Sciences, Dental School, University of Turin (UNITO), Turin, Piedmont, Italy.
| | - Gabriel Kalil Rocha Pereira
- Post-Graduate Program in Oral Sciences (Prosthodontics Units), Faculty of Dentistry, Universidade Federal de Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
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Figueiredo PS, Spazzin AO, Bacchi A, Alessandretti R. Effect of preheating and ultrasound application of resin-based luting agents on the failure load of a lithium disilicate glass-ceramic. J Prosthodont 2024; 33:396-401. [PMID: 37300878 DOI: 10.1111/jopr.13722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 05/31/2023] [Indexed: 06/12/2023] Open
Abstract
PURPOSE To assess the effect of preheating resin-based materials and ultrasound application on the failure load of a lithium disilicate glass-ceramic. MATERIALS AND METHODS Ninety ceramic specimens were produced (14×12×1.0 mm) and divided into 9 groups (n = 10) to be bonded to a dentin analog (Nema G10) with light-cured luting agent (LC), flowable resin composite (FL), and supra-nano filled resin composite (SN), as follows: LC/R - LC at room temperature; LC/P - preheated LC; LC/P/U - preheated LC and Ultrasound; FL/R - FL at room temperature; FL/P - preheated FL; FL/P/U - preheated FL and Ultrasound; SN/R - SN at room temperature; SN/P - preheated SN; SN/P/U - preheated SN and Ultrasound. The failure load test was performed in a universal testing machine with the aid of acoustic detection. The data was analyzed with two-way ANOVA (for failure load) and Weibull statistics (Weibull modulus - m and characteristic strength, based on 95% confidence intervals - CI). RESULTS The analyses of failure load revealed no statistically significant difference among groups considering the type of luting agent (P = 0.075; F = 2,673), the application method (P = 0.772; F = 2,259), and the interaction between them (P = 0.297; F = 1,248). The characteristic strength did not show differences among groups (95% CI). The m, which indicates structural reliability, showed lower values for SN/P/U and SN/P, with a difference from other selected groups (95% CI). CONCLUSION Preheating of resin-based materials and ultrasound application did not affect the failure load of lithium disilicate glass-ceramic. Lower reliability was observed with supra-nano filled resin composite.
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Affiliation(s)
| | - Aloísio Oro Spazzin
- Graduate Program in Dentistry, School of Dentistry, Atitus Education, Passo Fundo, RS, Brazil
| | - Atais Bacchi
- Graduate Program in Dentistry, Paulo Picanço School of Dentistry (FACPP), Fortaleza, CE, Brazil
| | - Rodrigo Alessandretti
- Graduate Program in Dentistry, School of Dentistry, Atitus Education, Passo Fundo, RS, Brazil
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Contreras LPC, Rodrigues CS, Zucuni CP, Valandro LF, Marocho SMS, de Melo RM. Fatigue behavior of multilayer ceramic structures in traditional and reverse layering designs. J Prosthodont 2024; 33:389-395. [PMID: 37201944 DOI: 10.1111/jopr.13705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 05/11/2023] [Accepted: 05/12/2023] [Indexed: 05/20/2023] Open
Abstract
PURPOSE This study evaluated the fatigue failure load (FFL) and the number of cycles for fatigue failure (CFF) of traditional (porcelain layer up) and reversed (zirconia layer up) designs of porcelain-veneered zirconia samples prepared with heat-pressing or file-splitting techniques. MATERIALS AND METHODS Zirconia discs were prepared and veneered with heat-pressed or machined feldspathic ceramic. The bilayer discs were bonded onto a dentin-analog according to the bilayer technique and sample design: traditional heat-pressing (T-HP), reversed heat-pressing (R-HP), traditional file-splitting with fusion ceramic (T-FC), reversed file-splitting with fusion ceramic R-FC), traditional file-splitting with resin cement (T-RC), and reversed file-splitting with resin cement (R-RC). The fatigue tests were performed using the stepwise approach at 20 Hz, 10,000 cycles/step, step-size of 200 N starting at 600 N, and proceeding until failure detection or up to 2600 N if enduring. The failure modes (from radial and/or cone cracks) were analyzed in a stereomicroscope. RESULTS The reversed design decreased the FFL and CFF of bilayers prepared with heat-pressing and file-splitting with fusion ceramic. The T-HP and T-FC reached the highest results, which were statistically similar between them. The bilayers prepared by the file-splitting with resin cement (T-RC and R-RC) were similar to the R-FC and R-HP groups regarding FFL and CFF. Almost all reverse layering samples failed by radial cracks. CONCLUSIONS The reverse layering design did not improve the fatigue behavior of porcelain veneered zirconia samples. The three bilayer techniques behaved similarly when used in the reversed design.
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Affiliation(s)
- Lisseth Patricia Claudio Contreras
- Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University (UNESP), São José dos Campos, São Paulo, Brazil
| | - Camila Silva Rodrigues
- Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University (UNESP), São José dos Campos, São Paulo, Brazil
- Graduate Program in Dentistry, Federal University of Pelotas (UFPel), Pelotas, Rio Grande do Sul, Brazil
| | - Camila Pauleski Zucuni
- Department of Restorative Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil
| | - Luiz Felipe Valandro
- Department of Restorative Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil
| | | | - Renata Marques de Melo
- Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University (UNESP), São José dos Campos, São Paulo, Brazil
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Pilecco RO, Machry RV, Ribeiro VF, Dal Piva AMDO, Tribst JPM, Kleverlaan CJ, Moraes RR, Pereira GKR. Impact of try-in paste removal on the fatigue behavior of bonded lithium disilicate ceramics. J Mech Behav Biomed Mater 2024; 151:106394. [PMID: 38218045 DOI: 10.1016/j.jmbbm.2024.106394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 01/06/2024] [Accepted: 01/07/2024] [Indexed: 01/15/2024]
Abstract
This in vitro study assessed the effectiveness of three cleaning protocols (air-water spray, 37% phosphoric acid, or Ivoclean) on lithium disilicate restorations' fatigue behavior after try-in paste application, compared to a clean condition. Lithium disilicate discs (IPS e.max CAD, Ivoclar) with Ø-= 12 mm and 1 mm thickness were prepared from prefabricated CAD-CAM blocks, polished, subjected to CAD-CAM milling topography simulation and crystallization. After, etching with 5% hydrofluoric acid and the application of try-in paste (Variolink try-in paste shade white; load of 2.5 N for 5 min) was performed. Discs that received try-in paste were divided into three groups according to the removal protocol: SPRAY - air-water spray for 30 s; HPO - active application of 37% phosphoric acid for 60 s; IVOC - application of Ivoclean for 20 s. Control group (CTRL group) did not receive the try-in paste application. Half of the specimens (n= 15) were tested in the baseline condition (24 h up to 7 days), and the others underwent 25,000 thermal cycles (5 - 55 °C) + 210 days of distilled water storage (37 °C). Additional specimens (n= 3) underwent monotonic testing (1 mm/min). Fatigue testing involved a cyclic fatigue approach (20 Hz, initial load = 100 N - 5000 cycles, step size = 50 N - 10,000 cycles) until a visible crack appeared. Fractographic and topographic analyses were performed. Fatigue data were statistically analyzed with two-way ANOVA, Kaplan-Meier log-rank (Mantel-Cox), and independent t-test (α= 0.05). In the baseline condition, the IVOC group resulted in a superior fatigue behavior compared to the CTRL and SPRAY groups, but similar to the HPO group. The HPO and SPRAY presented a similar fatigue behavior to the CTRL group. It was noticed a decrease in fatigue behavior after aging, which resulted in all the cleaning protocols leading to similar fatigue behavior compared to the CTRL group. On the SPRAY group surface, try-in pastes remnants were noticed. In summary, despite a detrimental impact at baseline conditions, all tested cleaning protocols seem proper to remove the try-in paste from the ceramic's surface in the long-term evaluation.
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Affiliation(s)
- Rafaela Oliveira Pilecco
- Post-Graduate Program in Oral Sciences, Center for Development of Advanced Materials, Division of Prosthodontics-Biomaterials, Universidade Federal de Santa Maria (UFSM), Santa Maria, RS, Brazil.
| | - Renan Vaz Machry
- Post-Graduate Program in Oral Sciences, Center for Development of Advanced Materials, Division of Prosthodontics-Biomaterials, Universidade Federal de Santa Maria (UFSM), Santa Maria, RS, Brazil.
| | | | - Amanda Maria de Oliveira Dal Piva
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam en Vrije Universiteit, Amsterdam, the Netherlands.
| | - João Paulo Mendes Tribst
- Department of Reconstructive Oral Care, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam en Vrije Universiteit, Amsterdam, the Netherlands.
| | - Cornelis Johannes Kleverlaan
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam en Vrije Universiteit, Amsterdam, the Netherlands.
| | - Rafael R Moraes
- Graduate Program in Dentistry, Universidade Federal de Pelotas (UFPel), Pelotas, RS, Brazil.
| | - Gabriel Kalil Rocha Pereira
- Post-Graduate Program in Oral Sciences, Center for Development of Advanced Materials, Division of Prosthodontics-Biomaterials, Universidade Federal de Santa Maria (UFSM), Santa Maria, RS, Brazil.
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Dalla-Nora F, Da Rosa LS, Pereira GKR, Valandro LF, Rippe MP. Is dentin analogue material a viable substitute for human dentin in fatigue behavior studies? J Mech Behav Biomed Mater 2024; 150:106312. [PMID: 38134583 DOI: 10.1016/j.jmbbm.2023.106312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/04/2023] [Accepted: 12/07/2023] [Indexed: 12/24/2023]
Abstract
This study aimed to compare the fatigue performance of a lithium disilicate ceramic cemented on different substrates (human dentin and glass fiber-reinforced epoxy resin - GFRER), treated with different types of conditioning (CTR - without surface conditioning; HF5 - 5% hydrofluoric acid; HF10 - 10% hydrofluoric acid; H3PO4 - phosphoric acid 37%; SAND - sandblasting with aluminum oxide). The occlusal surface of human molars (DENT group) (n = 15) was ground for dentin exposure and the root portion was cut, then the dentin slice (2.0 mm thick) was conditioned with 37% phosphoric acid and a dual-curing dental adhesive was applied. The GFRER in a round-rod format was cut into discs (Ø = 10 mm, 2.0 mm thick). Lithium disilicate glass ceramic blocks (IPS e.max CAD, Ivoclar, Schaan, Liechtenstein) were shaped into a cylinder format and cut, resulting in 90 discs (Ø = 10 mm, 1.5 mm thick). The substrate materials of each group were etched according to the groups and the ceramic was etched with 5% hydrofluoric acid for 30 s. A silane coupling agent was applied over the cementation surface in ceramic and GFRER surfaces and a dual cement was used for cementation (ceramic/GFRER or dentin). The disc/disc sets were submitted to thermocycling (25,000 cycles + storage for 6 months), and then tested in step-wise accelerated cyclic fatigue test. The failure pattern and topography were analyzed and the roughness and contact angle were measured before and after surface treatment. The DENT group presented the lowest load to failure values and number of cycles to failure in fatigue (637.33 N; 118.333), showing no statistical similarity with any of the other tested groups (p < 0.05). The topographic analysis showed that all proposed surface treatments modified the substrate surface when compared to the CTR group. All of the fractographical inspections demonstrated failure by radial crack. Considering the roughness analysis, the post-etched DENT group showed similar roughness to all groups of GFRER materials with their surface treated, except for SAND, which showed greater roughness and statistically different from the other groups. The DENT group (49.5) showed statistically different post-conditioning contact angle values from the HF10 group (96.5) and similar to the other groups. The glass fiber-reinforced epoxy resin was not able to simulate the results presented by the human dentin substrate when cemented to lithium disilicate regarding fatigue failure load and number of cycles for failure, regardless of the surface treatment. Lithium disilicate cemented on dentin analogue overestimates the load values for fatigue failure.
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Affiliation(s)
- F Dalla-Nora
- MSciD and PhD Post-Graduate Program in Oral Science [Prosthodontics Units], Faculty of Dentistry, Federal University of Santa Maria [UFSM], Avenue Roraima 1000, Building 26F, room 2383, Zip Code: 97105-900, Santa Maria, Rio Grande do Sul State, Brazil.
| | - L S Da Rosa
- MSciD and PhD Post-Graduate Program in Oral Science [Prosthodontics Units], Faculty of Dentistry, Federal University of Santa Maria [UFSM], Avenue Roraima 1000, Building 26F, room 2383, Zip Code: 97105-900, Santa Maria, Rio Grande do Sul State, Brazil.
| | - G K R Pereira
- MSciD and PhD Post-Graduate Program in Oral Science [Prosthodontics Units], Faculty of Dentistry, Federal University of Santa Maria [UFSM], Avenue Roraima 1000, Building 26F, room 2383, Zip Code: 97105-900, Santa Maria, Rio Grande do Sul State, Brazil.
| | - L F Valandro
- MSciD and PhD Post-Graduate Program in Oral Science [Prosthodontics Units], Faculty of Dentistry, Federal University of Santa Maria [UFSM], Avenue Roraima 1000, Building 26F, room 2383, Zip Code: 97105-900, Santa Maria, Rio Grande do Sul State, Brazil.
| | - M P Rippe
- MSciD and PhD Post-Graduate Program in Oral Science [Prosthodontics Units], Faculty of Dentistry, Federal University of Santa Maria [UFSM], Avenue Roraima 1000, Building 26F, room 2383, Zip Code: 97105-900, Santa Maria, Rio Grande do Sul State, Brazil.
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9
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da Rosa LS, Soares PM, Packaeser MG, Chiapinotto GF, Bacchi A, Tribst JPM, Kleverlaan CJ, Pereira GKR. Effect of abutment screw-access hole on the fatigue performance of implant-supported lithium-disilicate luted simplified restorations. J Mech Behav Biomed Mater 2024; 150:106254. [PMID: 38035645 DOI: 10.1016/j.jmbbm.2023.106254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 11/13/2023] [Accepted: 11/15/2023] [Indexed: 12/02/2023]
Abstract
The present study aimed to evaluate the impact of the existence of an abutment screw-access hole and the filling effects on the fatigue mechanical behavior of a luted lithium-disilicate glass-ceramic. Seventy-two discs (Ø = 10 mm, 1.0 mm in thickness) of lithium disilicate (IPS e.max CAD, Ivoclar AG) were obtained from prefabricated blocks. Thirty-six abutment specimens of an opaque zirconia (Yz - IPS e.max ZirCAD, Ivoclar AG) and titanium (Ti - Luminesse Ti-Cam discs, Talladium Inc.) were confectioned, and allocated according to 6 groups: Yz and Ti rigid (without screw access hole); Yz unfilled, Yz filled, Ti unfilled and Ti filled (with the screw access (Ø = 2.5 mm) in the center). For the unfilled groups, only a polytetrafluoroethylene tape was used. Resin composite (Tetric N-Ceram, Ivoclar AG) was applied to the screw access hole for the filled groups (Yz and Ti). A cyclic fatigue test was carried out (load of 200 N, 10,000 cycles each; 20 Hz of frequency, step size of 100 N until failure detection (radial/cone crack). The fatigue failure load (FFL) and number of cycles until failure (CFF) were recorded for statistical purposes. The stress distribution (MPa) was evaluated by finite element analysis. A statistically positive effect of the abutment material and the presence of the screw access hole was observed (p ≤ 0.05). The rigid groups (without screw access holes) depicted almost 100% of survival after the fatigue tests. Among the other groups, the Yz-filled group showed the best performance (p ≤ 0.05), followed by the Yz unfilled group. The Ti groups depicted lower values of FFL and CFF, with the Ti unfilled group showing the most unfavorable fatigue behavior (p ≤ 0.05). The lowest tensile stress concentration in the restorative material was observed with the use of rigid abutments, the filled groups depicted intermediate values, while unfilled groups showed the highest stress concentration (Yz rigid = 306.3 MPa; Ti rigid = 310.4 MPa < Yz filled = 490.7 MPa; Ti filled = 498.9 MPa < Yz unfilled = 707.6 MPa; Ti unfilled = 719.7 MPa). Therefore, the presence of a screw-access hole decreases the mechanical performance of a lithium disilicate ceramic regardless of the abutment material. In the presence of a screw-access hole, zirconia abutments depicted a higher fatigue failure load when compared with titanium. The filling of the abutment screw-access hole with resin composite increased the mechanical performance of the simulated restoration.
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Affiliation(s)
- Lucas Saldanha da Rosa
- Post-Graduate Program in Oral Sciences (Prosthodontics Unit), Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Pablo Machado Soares
- Post-Graduate Program in Oral Sciences (Prosthodontics Unit), Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Maria Gabriela Packaeser
- Post-Graduate Program in Oral Sciences (Prosthodontics Unit), Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Gratcheva Falcão Chiapinotto
- Post-Graduate Program in Oral Sciences (Prosthodontics Unit), Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Atais Bacchi
- Post-Graduate Program in Dentistry, Paulo Picanço School of Dentistry (FACPP), Fortaleza, Ceará State, Brazil.
| | - João Paulo Mendes Tribst
- Department of Reconstructive Oral Care, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, North Holland, the Netherlands.
| | - Cornelis Johannes Kleverlaan
- Department of Dental Materials, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, North Holland, the Netherlands.
| | - Gabriel Kalil Rocha Pereira
- Post-Graduate Program in Oral Sciences (Prosthodontics Unit), Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
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10
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Ozkan Irem D, Alpkilic DS, Isler Deger S. The effect of pre-ceramic soldering on marginal and internal fit of 4-unit zirconia frameworks and monolithic zirconia fixed dental prostheses. Odontology 2024; 112:169-176. [PMID: 37422770 DOI: 10.1007/s10266-023-00826-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 05/31/2023] [Indexed: 07/11/2023]
Abstract
The aim of this study is to evaluate the effect of pre-ceramic soldering on the marginal and internal fit of 4-unit zirconia fixed dental prostheses (FPDs) that have two abutments and two pontics. 4-unit zirconia frameworks (Zirkonzahn ICE Translucent) (Z Group) and monolithic zirconia (Zirkonzahn Prettau) (M Group) FPDs were manufactured. Groups were divided into two groups (n = 10) control (ZC and MC) and soldering (ZS and MS). Samples of ZS and MS groups were cut into two pieces under cooling water and soldered with a bonding material (DCM Zircon HotBond). The marginal and internal fit of the restorations were measured from 36 points of each sample and cement space volume was calculated using reverse engineering software (Geomagic Design X). The mean and standard deviations were submitted to Generalized Linear Mixed Model (GLMM) analysis (α = 0.05). Statistical differences between groups before and after pre-ceramic soldering on point measurements were found. In total cement spacing measurements, a significant difference was found amongst all groups (P < 0.05). However, in premolars, a statistically significant difference was found between ZC and ZS groups and MC and MS groups (P < 0.05). All discrepancies after pre-ceramic soldering were found to be lower than before.
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Affiliation(s)
| | - Dilara Seyma Alpkilic
- Department of Prosthodontics, Faculty of Dentistry, Istanbul University, Beyazit Yerleşkesi, Beyazit, 34452, Istanbul, Turkey.
| | - Sabire Isler Deger
- Department of Prosthodontics, Faculty of Dentistry, Istanbul University, Beyazit Yerleşkesi, Beyazit, 34452, Istanbul, Turkey
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11
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Pilecco RO, da Rosa LS, Pereira GKR, Tribst JPM, May LG, Valandro LF. The loss of resin cement adhesion to ceramic influences the fatigue behavior of bonded lithium disilicate restorations. J Mech Behav Biomed Mater 2023; 148:106169. [PMID: 37837872 DOI: 10.1016/j.jmbbm.2023.106169] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 10/06/2023] [Accepted: 10/06/2023] [Indexed: 10/16/2023]
Abstract
When partial and/or non-retentive preparation, such as those for occlusal veneers, is indicated, a proper and stable adhesion is essential. Therefore, the aim of this in vitro study was to evaluate the effect of loss of adhesion in different regions of the bonding interface on the fatigue behavior of simplified lithium disilicate restorations. For this, lithium disilicate (IPS e.max CAD) discs (1 mm thick and Ø = 10 mm) were fabricated, polished with #400-, #600-, #1200-grit silicon carbide (SiC) papers, and crystallized. As substrate, fiber-reinforced resin epoxy discs (2.5 mm thick and Ø = 10 mm) were fabricated and polished with #600-grit SiC paper. The ceramic bonding surface was treated with 5% hydrofluoric acid and a silane-containing primer (Monobond N), while the substrate was etched with 10% hydrofluoric acid followed by the application of the bonding system primers (Primer A + B). A lacquer (nail polish) was used to simulate the loss of adhesion in specific areas according to the study design to compose the testing groups: bonded (control; did not received nail polish application); - non-bonded (loss of adhesion in the whole specimen area); - margin (loss of adhesion in the ceramic margin); - center (loss of adhesion in the ceramic central area). The adhesive area of partially bonded groups was 50% of the adhesive surface. Then, the discs (n = 12) were bonded to the respective substrate using a resin cement (Multilink N), light-cured, water-stored for 90 days, and subjected to thermocycling (25,000 cycles, 5° to 55 °C) before testing. A cyclic fatigue test was run (20 Hz, initial load of 200 N for 5000 cycles, 50 N step size for 10,000 cycles each until specimen failure), and the fatigue failure load and number of cycles for failure were recorded. As complementary analysis, finite element analysis (FEA) and scanning electron microscopy analysis were performed. Kaplan-Meier log-rank (Mantel-Cox) was conducted for survival analysis. The results showed that as the loss of adhesion reaches the central area, the worse is the fatigue behavior and the higher is the stress peak concentration in the ceramic bonding surface. The bonded specimens presented better fatigue behavior and stress distribution compared to the others. In conclusion in a non-retentive preparation situation, proper adhesion is a must for the restoration fatigue behavior even after aging; while the loss of adhesion reaches central areas the mechanical functioning is compromised.
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Affiliation(s)
- Rafaela Oliveira Pilecco
- Post-Graduate Program in Oral Sciences, Center for Development of Advanced Materials, Division of Prosthodontics-Biomaterials, Federal University of Santa Maria (UFSM), Santa Maria, Brazil.
| | - Lucas Saldanha da Rosa
- Post-Graduate Program in Oral Sciences, Center for Development of Advanced Materials, Division of Prosthodontics-Biomaterials, Federal University of Santa Maria (UFSM), Santa Maria, Brazil.
| | - Gabriel Kalil Rocha Pereira
- Post-Graduate Program in Oral Sciences, Center for Development of Advanced Materials, Division of Prosthodontics-Biomaterials, Federal University of Santa Maria (UFSM), Santa Maria, Brazil.
| | - João Paulo Mendes Tribst
- Department of Reconstructive Oral Care, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam, the Netherlands.
| | - Liliana Gressler May
- Post-Graduate Program in Oral Sciences, Center for Development of Advanced Materials, Division of Prosthodontics-Biomaterials, Federal University of Santa Maria (UFSM), Santa Maria, Brazil.
| | - Luiz Felipe Valandro
- Post-Graduate Program in Oral Sciences, Center for Development of Advanced Materials, Division of Prosthodontics-Biomaterials, Federal University of Santa Maria (UFSM), Santa Maria, Brazil.
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12
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Aragonez GC, Dalla-Nora F, Soares PM, Pereira GKR, Valandro LF, Dos Santos SS, Rippe MP. Load-bearing capacity under fatigue of bonded-yttria tetragonal zirconia polycrystals and -yttria-stabilized zirconia: Effects of the viscosity of a dual-cured resin cement. J Mech Behav Biomed Mater 2023; 148:106233. [PMID: 37976685 DOI: 10.1016/j.jmbbm.2023.106233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 11/04/2023] [Accepted: 11/07/2023] [Indexed: 11/19/2023]
Abstract
This study aimed to evaluate the effect of low and high viscosities of dual-cured resin cement on the mechanical fatigue behavior of yttria tetragonal zirconia polycrystals (3Y-TZP) and yttria-stabilized zirconia (4YSZ) adhesively luted to a dentin analogue (glass fiber-reinforced epoxy resin). Ceramic discs were randomly divided into four groups (n = 20) based on the following study factors: dual-cured resin cement viscosities (low and high) and zirconia microstructure (3Y-TZP and 4YSZ). The discs were treated by air abrasion with aluminum oxide particles (50 μm), followed by the application of primer, and then luted with high or low viscosity resin cement to the dentin analogue. Subsequently, the luted sets underwent a step-stress fatigue test, which involved an initial load of 200 N, step increments of 100 N, 10,000 cycles per step, and a frequency of 20 Hz. Data on fatigue failure load (FFL) and the number of cycles for failure (CFF) were collected and analyzed using survival tests, including Kaplan-Meier and Mantel-Cox analyses, as well as Weibull analysis. Additionally, topography analysis, fractographic features, bonding interface analysis, and Raman spectroscopy were performed. The results revealed that 3Y-TZP exhibited superior fatigue behavior compared to 4YSZ, regardless of the viscosity of the resin cement used for luting. Among all groups, 3Y-Low exhibited the best fatigue performance, while 4YSZ luted with low or high viscosity resin cements yielded the lowest fatigue behavior (FFL). There were no significant differences in Weibull modulus among the groups. After air abrasion, both ceramics showed similar topography. Raman analysis indicated that the surface of 3Y-TZP ceramics prior to sintering had a monoclinic phase, which transitioned predominantly to tetragonal phase peaks after sintering. A similar transition was observed in 4YSZ ceramics. In summary, 3Y-TZP exhibited superior mechanical fatigue behavior compared to 4YSZ. The influence of resin cement viscosity on fatigue behavior was more pronounced in 3Y-TZP, with low-viscosity resin cement enhancing its performance. However, the mechanical fatigue behavior of 4YSZ was less affected by the viscosity of the dual-cured resin cement, showing similar results with both low and high viscosities. In conclusion, 3Y-TZP demonstrated superior mechanical fatigue behavior compared to 4YSZ. The impact of resin cement viscosity on fatigue behavior was more pronounced in 3Y-TZP, with low-viscosity resin cement enhancing its performance. Conversely, the mechanical fatigue behavior of 4YSZ was less sensitive to the viscosity of the dual-cured resin cement, resulting in similar outcomes with both low and high viscosities.
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Affiliation(s)
- Gabriela Carrão Aragonez
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Odontology, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Fernanda Dalla-Nora
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Odontology, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Pablo Machado Soares
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Odontology, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Gabriel Kalil Rocha Pereira
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Odontology, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Luiz Felipe Valandro
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Odontology, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Sailer Santos Dos Santos
- Laboratory of Inorganic Materials, Department of Chemistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Marília Pivetta Rippe
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Odontology, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
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13
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Freitas JS, Souza LFB, Dellazzana FZ, Silva TMRD, Ribeiro L, Pereira GKR, May LG. Advanced lithium disilicate: A comparative evaluation of translucency and fatigue failure load to other ceramics for monolithic restorations. J Mech Behav Biomed Mater 2023; 148:106192. [PMID: 37865017 DOI: 10.1016/j.jmbbm.2023.106192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/12/2023] [Accepted: 10/13/2023] [Indexed: 10/23/2023]
Abstract
The aim of this in vitro study was to evaluate the surface roughness, translucency, fatigue failure load (FFL), and number of cycles for fatigue failure (CFF) of a recently released lithia-based material called advanced lithium disilicate and three other ceramics indicated for monolithic restorations. First, ALD (advanced lithium disilicate, CEREC Tessera, Dentsply Sirona), LD (lithium disilicate, IPS e. max CAD, Ivoclar), LS (lithium silicate-disilicate, Suprinity, Vita Zahnfabrik), and 4Y-PSZ (Yttria-stabilized zirconia, IPS e.max ZirCAD MT, Ivoclar) discs (n = 15, Ø = 10 mm and thickness = 1.0 mm) were fabricated from CAD/CAM blocks/discs, A2 shade. The discs were sintered/crystallized and subsequently analyzed by a rugosimeter (Mitutoyo SJ-410) to determine Ra and Rz surface roughness parameters. Next, they were evaluated to determine the translucency parameter (TP) using a bench-top spectrophotometer (SP60, EX-Rite). The discs were subsequently cemented to glass fiber epoxy resin discs, and the specimens were tested under cyclic loading (Step-test), immersed in distilled water at a frequency of 20 Hz, with an initial cyclic load of 200 N for 5,000 cycles and increments of 50 N every 10,000 cycles until failure. Fatigue failure load (FFL) and number of cycles for fatigue failure (CFF) were recorded for subsequent Kaplan Meier analysis, with post-hoc Mantel-Cox and Weibull analysis (α = 0.05). Complementary fractographic, topographic and energy dispersive spectroscopy analyses (EDS) were performed. 4Y-PSZ showed higher survival (p < 0.05), with higher FFL and CFF (1077 N; 180,333 cycles), followed by LD (980 N; 161,000 cycles), LS (937 N; 152,333 cycles) and ALD (910 N; 147,000 cycles). No differences were observed between the tested groups regarding Weibull modulus. ALD presented TP (28.14) equal to DL (28.27) and higher than LS (25.51). All lithia-based materials had higher translucency than 4Y-PSZ (TP = 8.62) (p < 0.05). ALD appears to have a similar elemental composition to LD and LSD for oxygen and silicon. ALD and LSD have a similar zirconium content. Fractures originated on the cemented surface of the ceramic discs. Lithia-based ceramics showed lower surface roughness, with ALD (Ra = 0.04 μm; Rz = 0.66 μm) showing the lowest values (p < 0.05). Despite showing lower FFL when compared to LD and 4Y-PSZ, ALD has compatible translucency and mechanical fatigue performance with its indication for fabricating monolithic, anterior and posterior adhesively cemented single-unit restorations. However, further studies are needed to substantiate its clinical performance.
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Affiliation(s)
- Júlia Saccol Freitas
- MScD and PhD Post-Graduate Program in Oral Science, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Luiza Freitas Brum Souza
- MScD and PhD Post-Graduate Program in Oral Science, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Fernando Zurlo Dellazzana
- Faculty of Denstistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | | | - Luiza Ribeiro
- Faculty of Denstistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Gabriel Kalil Rocha Pereira
- MScD and PhD Post-Graduate Program in Oral Science, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Liliana Gressler May
- MScD and PhD Post-Graduate Program in Oral Science, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
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14
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Tomm AGF, Machado PS, Rosa LSD, Pereira GKR, Spazzin AO, Alessandretti R. Fatigue resistance of monolithic and multilayer zirconia crowns using veneer layering or CAD-on technique. Braz Dent J 2023; 34:150-159. [PMID: 38133089 PMCID: PMC10742353 DOI: 10.1590/0103-6440202305687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 11/24/2023] [Indexed: 12/23/2023] Open
Abstract
This study aims to evaluate the fatigue resistance of monolithic zirconia (Yz) and multilayer ceramic structures using the CAD-on technique in different thicknesses. Fifty (N=50) standardized single crowns preparations were made in fiberglass-reinforced epoxy resin (NEMA grade G10), digitalized, and restorations were machined in CAD-CAM, composing 5 groups (n= 10): Control: 1.5 mm (milled zirconia framework + manual layered porcelain); Yz monolithic 1.5 mm; Yz monolithic 1.0 mm; CAD-on 1.5 mm; and CAD-on 1.0 mm (milled zirconia framework 0.5 mm thickness bonded by a low fuse ceramic to a milled lithium disilicate layer of 1.0 mm or 0.5 mm, respectively). The G10 bases were conditioned with 10% hydrofluoric acid; the crowns were air abraded with 110 μm alumina particles; and then luted onto each other with self-adhesive resin cement. A cyclic fatigue test was performed (initial load: 400N for 10,000 cycles, frequency of 20 Hz, step size of 200N) until failure, and the data was submitted to a survival statistical analysis. No failures were observed at Yz monolithic 1.5 mm. High and similar performance was observed for Cad-On groups and Yz monolithic 1.0 mm. The control group depicted the worst behavior. The Weibull modulus of CAD-on 1.5 mm was higher than the control while being similar to the other conditions. Both the monolithic systems and the CAD-on technique showed high and similar fatigue fracture behavior and survival rates, which were also higher than the control bilayer system. Both systems reduced the occurrence of delamination failures, making them suitable for clinical use.
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Affiliation(s)
| | - Pablo Soares Machado
- Post-Graduate Program in Oral Sciences, Center for Development of Advanced Materials, Division of Prosthodontics-Biomaterials, Federal University of Santa Maria (UFSM), Santa Maria, Brazil
| | - Lucas Saldanha da Rosa
- Post-Graduate Program in Oral Sciences, Center for Development of Advanced Materials, Division of Prosthodontics-Biomaterials, Federal University of Santa Maria (UFSM), Santa Maria, Brazil
| | - Gabriel Kalil Rocha Pereira
- Post-Graduate Program in Oral Sciences, Center for Development of Advanced Materials, Division of Prosthodontics-Biomaterials, Federal University of Santa Maria (UFSM), Santa Maria, Brazil
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15
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Choo SS, Ko KH, Huh YH, Park CJ, Cho LR. Fatigue resistance of anterior monolithic crowns produced from CAD-CAM materials: An in vitro study. J Prosthet Dent 2023; 130:620-628. [PMID: 34980473 DOI: 10.1016/j.prosdent.2021.09.034] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 09/29/2021] [Accepted: 09/29/2021] [Indexed: 10/19/2022]
Abstract
STATEMENT OF PROBLEM Lithium disilicate and 5 mol% yttria partially stabilized zirconia (5Y-PSZ) are commonly used for anterior restorations. However, studies comparing the durability of 5Y-PSZ and lithium disilicates are sparse. PURPOSE The purpose of this in vitro study was to investigate the fracture load of anterior monolithic crowns made of 2 lithium disilicates and a 5Y-PSZ under dynamic loading. MATERIAL AND METHODS Titanium abutments of the maxillary incisors were prepared (N=48, 8 for each group). Monolithic anterior crowns were made from the lithium disilicates (e.max CAD, Rosetta SM) and 5Y-PSZ (Katana UTML). After cementation, the specimens were stored in water for 24 hours and then thermocycled 10 000 times. Dynamic loading (70 N, 200 000 cycles, 1 Hz) was applied to half the specimens. The fracture load was measured by using a universal testing machine. The fracture patterns were analyzed and fractography applied. Two-way ANOVA and the Fisher exact test were used for statistical analysis (α=.05). RESULTS The material and dynamic loading affected the fracture load of the anterior monolithic crowns (P<.05). However, there was no interaction between the material and the dynamic loading (P=.079). Both lithium disilicates had higher fracture loads than 5Y-PSZ (P<.05). The fracture load of each specimen was reduced after dynamic loading (P<.05). Lithium disilicate showed marginal and bulk fractures, and 5Y-PSZ presented catastrophic fractures (P<.001). CONCLUSIONS 5Y-PSZ materials with large grains and low flexural strength may be less resistant to fractures under dynamic loading than lithium disilicates.
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Affiliation(s)
- Seung-Sik Choo
- Graduate student, Department of Prosthodontics and Research Institute of Oral Science, College of Dentistry, Gangneung-Wonju National University, Gangneung, Republic of Korea
| | - Kyung-Ho Ko
- Assistant Professor, Department of Prosthodontics and Research Institute of Oral Science, College of Dentistry, Gangneung-Wonju National University, Gangneung, Republic of Korea
| | - Yoon-Hyuk Huh
- Associate Professor, Department of Prosthodontics and Research Institute of Oral Science, College of Dentistry, Gangneung-Wonju National University, Gangneung, Republic of Korea
| | - Chan-Jin Park
- Professor, Department of Prosthodontics and Research Institute of Oral Science, College of Dentistry, Gangneung-Wonju National University, Gangneung, Republic of Korea
| | - Lee-Ra Cho
- Professor, Department of Prosthodontics and Research Institute of Oral Science, College of Dentistry, Gangneung-Wonju National University, Gangneung, Republic of Korea.
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16
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Velho HC, Dapieve KS, Grassi EDA, Borges ALS, de Melo Marinho RM, Pereira GKR, Venturini AB, Valandro LF. Fatigue behavior, failure mode, and stress distribution of occlusal veneers: influence of the prosthetic preparation cusp inclinations and the type of restorative material. Clin Oral Investig 2023; 27:5539-5548. [PMID: 37490118 DOI: 10.1007/s00784-023-05173-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Accepted: 07/13/2023] [Indexed: 07/26/2023]
Abstract
OBJECTIVE To evaluate the effects of cusp inclination of the prosthetic preparation's occlusal surface and type of restorative material on the fatigue behavior, failure mode, and stress distribution of occlusal veneers. MATERIALS AND METHODS Glass fiber-reinforced epoxy resin prosthetic preparations for occlusal veneers with three different occlusal surface cusp inclination degrees (0°, 15°, and 30°) were produced and assigned into six testing groups (n = 11) according to the cusp inclination (0°, 15°, or 30°) and type of restorative material (lithium disilicate-LD or resin composite-RC). Despite different substrate preparation cusp inclination degrees, the restorations were designed maintaining 30° inclination between the cusps at the occlusal surface and a thickness of 0.7 mm at the central groove region of the restorations to be machined in a CAD/CAM system. After cementation, the specimens were stored for about 7 days (under water at 37 °C), and subsequently submitted to a load to failure test (n = 2) and an intermittent cyclic fatigue test (n = 9) (initial load: 100 N; step size: 50 N; cycles/step: 10,000; loading frequency: 20 Hz; loading piston: 6-mm-diameter stainless steel) until observing cracks. The data were analyzed by two-way ANOVA, Kaplan-Meier, and Mantel-Cox post hoc tests. Finite element analysis (FEA) and fractographic analyses were performed. RESULTS The fatigue performance of LD and RC occlusal veneers was evaluated based on different prosthetic preparation cusp inclinations. The 0° inclination showed the best fatigue performance for both materials (LD: 944N, RC: 861N), while the 15° and 30° inclinations had lower values (LD: 800N and 533N, RC: 739N and 717N, respectively). The study also found that for a 0° inclination, LD occlusal veneers performed better than RC ones (LD: 944 N > RC: 861N), while for a 30° inclination, RC occlusal veneers had better fatigue performance than LD ones (LD: 533N < RC: 717N). No significant difference was observed between the materials for a 15° inclination (LD: 800N = RC: 739N). The FEA results showed a higher tensile stress concentration on lithium disilicate than on resin composite occlusal veneers. All lithium disilicate occlusal veneers showed radial crack failures, while resin composite occlusal veneers showed Hertzian cone cracks and radial cracks combined. CONCLUSION Considering mechanical perspective only, RC occlusal veneers should be indicated when prosthetic preparation cusps inclinations are 30°. When 0° prosthetic preparation cusps inclinations are observed, LD occlusal veneers will behave mechanically better. When a 15° cusp inclination is preserved, both restorative materials behave similarly.
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Affiliation(s)
- Helder Callegaro Velho
- Post-Graduate Program in Oral Science, Prosthodontics-Biomaterials Unit, School of Dentistry, Center for Development of Advanced Materials, Federal University of Santa Maria, UFSM Campus, 1000 Roraima Av., T Street, Building 26H, Santa Maria, Rio Grande Do Sul, 97105-900, Brazil
| | - Kiara Serafini Dapieve
- Post-Graduate Program in Oral Science, Prosthodontics-Biomaterials Unit, School of Dentistry, Center for Development of Advanced Materials, Federal University of Santa Maria, UFSM Campus, 1000 Roraima Av., T Street, Building 26H, Santa Maria, Rio Grande Do Sul, 97105-900, Brazil
| | - Elisa Donária Aboucauch Grassi
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), 777, Engenheiro Francisco José Longo Av, São José Dos Campos, São Paulo, 12245-000, Brazil
| | - Alexandre Luiz Souto Borges
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), 777, Engenheiro Francisco José Longo Av, São José Dos Campos, São Paulo, 12245-000, Brazil
| | - Renata Marques de Melo Marinho
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), 777, Engenheiro Francisco José Longo Av, São José Dos Campos, São Paulo, 12245-000, Brazil
| | - Gabriel Kalil Rocha Pereira
- Post-Graduate Program in Oral Science, Prosthodontics-Biomaterials Unit, School of Dentistry, Center for Development of Advanced Materials, Federal University of Santa Maria, UFSM Campus, 1000 Roraima Av., T Street, Building 26H, Santa Maria, Rio Grande Do Sul, 97105-900, Brazil
| | - Andressa Borin Venturini
- Post-Graduate Program in Oral Science, Prosthodontics-Biomaterials Unit, School of Dentistry, Center for Development of Advanced Materials, Federal University of Santa Maria, UFSM Campus, 1000 Roraima Av., T Street, Building 26H, Santa Maria, Rio Grande Do Sul, 97105-900, Brazil
| | - Luiz Felipe Valandro
- Post-Graduate Program in Oral Science, Prosthodontics-Biomaterials Unit, School of Dentistry, Center for Development of Advanced Materials, Federal University of Santa Maria, UFSM Campus, 1000 Roraima Av., T Street, Building 26H, Santa Maria, Rio Grande Do Sul, 97105-900, Brazil.
- Prosthodontics-Biomaterials Unit, Faculty of Odontology, Federal University of Santa Maria, UFSM Campus, 1000 Roraima Av., T Street, Building 26F, Room 2386, Santa Maria, Rio Grande Do Sul, 97105-900, Brazil.
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Alves WG, Souza LFB, Pereira GKR, Valandro LF, Kapczinski MP, Mengatto CM, Fraga S. Fit and fatigue behavior of CAD-CAM lithium disilicate crowns. J Prosthet Dent 2023; 130:241.e1-241.e8. [PMID: 37328406 DOI: 10.1016/j.prosdent.2023.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 05/19/2023] [Accepted: 05/19/2023] [Indexed: 06/18/2023]
Abstract
STATEMENT OF PROBLEM New computer-aided design and computer-aided manufacturing (CAD-CAM) lithium disilicate glass-ceramics have been marketed. However, information concerning their biomechanical behavior is lacking. PURPOSE The purpose of this in vitro study was to compare the fit and fatigue behavior of two recently introduced CAD-CAM lithium disilicate materials with the standard IPS e.max CAD ceramic and to investigate the effect of the thermal treatment for crystallization on crown fit. MATERIAL AND METHODS Monolithic crowns (n=15) were milled from 3 CAD-CAM lithium disilicates: IPS e.max CAD (Ivoclar AG), Rosetta SM (Hass), and T-lithium (Shenzhen Upcera Dental Technology). Marginal and internal fit were evaluated using the replica technique before and after crystallization, and the fatigue behavior of the luted crowns was evaluated by the step-stress method. One-way ANOVA and the Tukey test were used to compare fit among the materials. Fatigue failure load was evaluated by the Kaplan-Meier and Mantel-Cox tests. The effect of crystallization on fit was evaluated with the paired t test (α=.05). RESULTS Marginal fit was different between IPS e.max CAD (74 μm) and Rosetta SM (63 μm) (P=.02). T-lithium was similar to the other ceramics (68 μm) (P>.05). Occlusal internal space was similar among all materials (P=.69). Fatigue failure loads of Rosetta SM (1160 N) and T-lithium (1063 N) were similar to IPS e.max CAD (1082 N) (P>.05). The fatigue failure load of Rosetta SM was higher than that of T-lithium (P=.04). Crystallization reduced the axial internal space of all materials (P<.05) without significantly affecting marginal fit (P>.05). CONCLUSIONS The fit and fatigue behavior of Rosetta SM and T-lithium were similar to that of IPS e.max CAD. Crystallization reduced the internal space of the crowns.
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Affiliation(s)
- William Garcia Alves
- Graduate student, Department of Conservative Dentistry, School of Dentistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil
| | - Luiza Freitas Brum Souza
- Postgraduate Student, Post-Graduate Program in Dental Science, Prosthodontics Unit, Department of Restorative Dentistry, Universidade Federal de Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil
| | - Gabriel Kalil Rocha Pereira
- Adjunct Professor, Department of Restorative Dentistry, Universidade Federal de Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil
| | - Luiz Felipe Valandro
- Professor, Department of Restorative Dentistry, Universidade Federal de Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil
| | - Myriam Pereira Kapczinski
- Associate Professor, Department of Conservative Dentistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil
| | - Cristiane Machado Mengatto
- Associate Professor, Department of Conservative Dentistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil
| | - Sara Fraga
- Adjunct Professor, Department of Conservative Dentistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil.
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18
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Rizzatto LV, Meneghetti D, Di Domênico M, Facenda JC, Weber KR, Corazza PH, Borba M. Effect of the type of resin cement on the fracture resistance of chairside CAD-CAM materials after aging. J Adv Prosthodont 2023; 15:136-144. [PMID: 37441719 PMCID: PMC10333098 DOI: 10.4047/jap.2023.15.3.136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 06/05/2023] [Accepted: 06/20/2023] [Indexed: 07/15/2023] Open
Abstract
PURPOSE The study objective was to evaluate the influence of the type of resin cement on the flexural strength and load to fracture of two chairside CAD-CAM materials after aging. MATERIALS AND METHODS A polymer-infiltrated ceramic network (PICN) and a nanoceramic resin (RNC) were used to produce the specimens. Two types of dual-cure resin cements, a self-adhesive and a universal, were investigated. Bilayer specimens were produced (n = 10) and aged for 6 months in a humid environment before the biaxial flexural strength test (σf). Bonded specimens were subjected to a mechanical aging protocol (50 N, 2 Hz, 37℃ water, 500,000 cycles) before the compressive load test (Lf). σf and Lf data were analyzed using two-way ANOVA and Tukey tests (α = .05). Chi-square test was used to analyze the relationship between failure mode and experimental group (α = .05). RESULTS The type of resin cement and the interaction between factors had no effect on the σf and Lf of the specimens, while the type of restorative material was significant. RNC had higher σf and Lf than PICN. There was a significant association among the type of cracks identified for specimens tested in Lf and the restorative material. CONCLUSION The type of resin cement had no effect on the flexural strength and load to fracture of the two investigated CAD-CAM chairside materials after aging.
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Affiliation(s)
| | - Daniel Meneghetti
- School of Dentistry, University of Passo Fundo, Passo Fundo, RS, Brazil
| | - Marielle Di Domênico
- Graduate Program in Dentistry, University of Passo Fundo, Passo Fundo, RS, Brazil
| | - Júlia Cadorin Facenda
- Graduate Program in Dentistry, University of Passo Fundo, Passo Fundo, RS, Brazil
- Graduate Program in Dentistry, Federal University of Pelotas, Pelotas, RS, Brazil
| | - Katia Raquel Weber
- Graduate Program in Dentistry, University of Passo Fundo, Passo Fundo, RS, Brazil
- Department of Dentistry, School of Health Sciences, Positivo University, Curitiba, PR, Brazil
| | | | - Márcia Borba
- Graduate Program in Dentistry, University of Passo Fundo, Passo Fundo, RS, Brazil
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19
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Weber KR, Meneghetti DE, Benetti P, Della Bona A, Griggs JA, Borba M. Influence of piston material on the fatigue behavior of a glass-ceramic. J Prosthet Dent 2023; 129:931-937. [PMID: 34482967 PMCID: PMC8888770 DOI: 10.1016/j.prosdent.2021.08.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 08/02/2021] [Accepted: 08/02/2021] [Indexed: 11/15/2022]
Abstract
STATEMENT OF PROBLEM The lack of standardization regarding the loading piston material used in fatigue tests could limit the interpretation of study findings. PURPOSE The purpose of this in vitro study was to evaluate the effect of the piston material on the fatigue behavior of a lithium disilicate glass-ceramic. MATERIAL AND METHODS Plate-shaped, 1.2-mm-thick, lithium disilicate glass-ceramic specimens were cemented onto a dentin analog substrate with resin cement. The specimens were divided into 4 groups according to the piston material used in the fatigue test (n=30): metal, glass fiber-reinforced epoxy resin, ceramic, and human tooth. The fatigue test was performed in a mechanical cycling machine by using the boundary technique at 2 Hz in distilled water at 37 °C. The fatigue data were analyzed by using the Weibull distribution and a lifetime-inverse power law relationship. Failures were evaluated with fractography and transillumination. RESULTS The Weibull modulus (β) was similar among groups. The exponent of crack growth (n) was significantly greater for glass fiber-reinforced epoxy resin and tooth groups than for metal and ceramic; therefore, the probability of failure (Pf) of glass-ceramic specimens loaded by resin and tooth pistons depended more on load amplitude. Specimens tested with tooth showed the highest value of K (characteristic lifetime), which is an indication of greater survival. Radial crack was the only failure mode observed for all experimental groups. CONCLUSIONS The piston material influenced the fatigue survival of the lithium disilicate glass-ceramic. The glass fiber-reinforced epoxy resin piston closely simulated the fatigue behavior induced by the human tooth on the evaluated glass-ceramic.
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Affiliation(s)
- Katia R Weber
- PhD student, Post-Graduation Program in Dentistry, Dental School, University of Passo Fundo (UPF), Passo Fundo, RS, Brazil
| | - Daniel E Meneghetti
- Predoctoral student, Dental School, University of Passo Fundo (UPF), Passo Fundo, RS, Brazil
| | - Paula Benetti
- Professor, Post-Graduation Program in Dentistry, Dental School, University of Passo Fundo (UPF), Passo Fundo, RS, Brazil
| | - Alvaro Della Bona
- Professor, Post-Graduation Program in Dentistry, Dental School, University of Passo Fundo (UPF), Passo Fundo, RS, Brazil
| | - Jason A Griggs
- Professor, Department of Biomedical Materials Science, University of Mississippi Medical Center, Jackson, Miss
| | - Márcia Borba
- Professor, Post-Graduation Program in Dentistry, University of Passo Fundo, Passo Fundo, RS, Brazil.
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20
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Gouda A, Sherif A, Wahba M, Morsi T. Effect of veneering material type and thickness ratio on flexural strength of bi-layered PEEK restorations before and after thermal cycling. Clin Oral Investig 2023; 27:2629-2639. [PMID: 36602589 PMCID: PMC10264476 DOI: 10.1007/s00784-022-04829-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 12/18/2022] [Indexed: 01/06/2023]
Abstract
OBJECTIVE The purpose of this study was evaluating the biaxial strength of bi-layered PEEK restorations before and after aging using different veneering materials in different thickness ratios. MATERIAL AND METHODS Ninety specimens of thickness 1.5 mm were divided into three groups according to their veneering material. Group (CAD LD): BioHPP discs veneered with CAD milled lithium disilicate (n=30), group (CAD C): BioHPP discs veneered with CAD milled composite (n=30), and group (LC): BioHPP discs veneered with conventionally layered composite (n=30). Each group was subdivided into 3 subgroups (n=10) according to the different thickness ratios between the core and the veneering material (TC:TV). Subgroup 1: TC:TV=1:0.5, subgroup 2: TC:TV=0.7:0.8, and subgroup 3: TC:TV=0.5:1. Half of the specimens of each subgroup were subjected to thermocycling, and the bi-axial flexural strength of all specimens was tested before and after aging. Three-way ANOVA followed by Bonferroni's post hoc test were used for data analysis. The significance level was set at P ≤ 0.05. RESULTS Material, thickness ratio, and aging all had a significant effect on biaxial flexural strength. (LC) group had the highest biaxial flexural strength. TC:TV=0.5:1 showed the lowest biaxial flexural strength. All groups showed significant decrease in biaxial flexural strength after aging. CONCLUSIONS Veneering material for PEEK together with the thickness ratio between the core and veneering material greatly affect the flexural strength of bi-layered restorations. Thermocycling negatively impacts the flexural strength of PEEK bi-layered restorations. CLINICAL SIGNIFICANCE According to the results of that study, PEEK cores are best veneered with conventionally layered composite with core to veneering thickness ratio being 1:0.5.
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Affiliation(s)
- Ahmed Gouda
- Postgraduate Student, Faculty of Oral and Dental Medicine, Future University in Egypt, Cairo, Egypt
| | - Ashraf Sherif
- Fixed Prosthodontics Department, Faculty of Oral and Dental Medicine, Future University in Egypt, Cairo, Egypt
| | - Mennatallah Wahba
- Fixed Prosthodontics Department, Faculty of Oral and Dental Medicine, Future University in Egypt, Cairo, Egypt
| | - Tarek Morsi
- Fixed Prosthodontics Department, Faculty of Dentistry, Ain Shams University, Cairo, Egypt
- Vice Dean Postgraduate Affairs. Faculty of Oral and Dental Medicine, Misr International University, Cairo, Egypt
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21
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Afshar K, Falahchai M, Ansarilari H, Tajziehchi G. Effect of CAD-CAM Framework Design Fabricated from Sintered Cobalt-Chromium Alloy on Fracture Resistance of Metal-Ceramic Restorations. Int J Dent 2023; 2023:3788590. [PMID: 39139497 PMCID: PMC11321897 DOI: 10.1155/2023/3788590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 03/29/2023] [Accepted: 04/27/2023] [Indexed: 08/15/2024] Open
Abstract
Introduction Porcelain fracture is a common problem of metal-ceramic restorations (MCRs). One suggested strategy to prevent it is to modify the metal framework design; however, the available information regarding the effect of framework design on porcelain fracture is scarce. Objective This study aimed to assess the effect of computer-aided design and computer-aided manufacturing (CAD-CAM) framework design fabricated from sintered cobalt-chromium (Co-Cr) alloy on fracture resistance of MCRs. Materials and Methods Twenty premolar metal dies were fabricated for this in vitro study. Ten standard frameworks were designed with 0.5 mm thickness, and 10 customized frameworks were designed with 1 mm thickness at the lingual margin and 0.5 mm thickness in all other areas. All specimens were fabricated from sintered Co-Cr alloy (Ceramill Sintron) using soft metal milling technology. After porcelain application, the specimens underwent thermocycling and cyclic loading for 3,000 cycles between 5 and 55°C. The fracture resistance was measured by a universal testing machine. The failure mode was also determined. Data were statistically analyzed by independent t-test (α = 0.05). Results The mean fracture resistance of porcelain was 2,379 ± 531 N in the standard and 2,557 ± 448 N in the customized group. No significant difference was found in fracture resistance of the two groups (P > 0.05). All specimens in both groups showed mixed failure. Conclusion The fracture resistance of porcelain and the failure mode were not affected by the framework design of MCRs fabricated from sintered Co-Cr alloy (Ceramill Sintron).
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Affiliation(s)
- Kourosh Afshar
- Department of Prosthodontics, Islamic Azad University Dental Branch, Tehran, Iran
| | - Mehran Falahchai
- Dental Sciences Research Center, Department of Prosthodontics, School of Dentistry, Guilan University of Medical Sciences, Rasht, Iran
| | - Homeira Ansarilari
- Department of Prosthodontics, Islamic Azad University Dental Branch, Tehran, Iran
| | - Gelareh Tajziehchi
- Department of Restorative Dentistry, School of Dentistry, Guilan University of Medical Sciences, Rasht, Iran
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Adabo GL, Longhini D, Baldochi MR, Bergamo ETP, Bonfante EA. Reliability and lifetime of lithium disilicate, 3Y-TZP, and 5Y-TZP zirconia crowns with different occlusal thicknesses. Clin Oral Investig 2023:10.1007/s00784-023-05001-6. [PMID: 37022529 DOI: 10.1007/s00784-023-05001-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 03/28/2023] [Indexed: 04/07/2023]
Abstract
OBJECTIVES To assess the probability of survival of crowns made with a 3Y-TZP, a 5Y-TZP, and a lithium disilicate. MATERIALS AND METHODS CAD-CAM premolar crowns with occlusal thicknesses of 1.0 mm or 1.5 mm and cemented on a metal dye. Step-stress accelerated life testing (SSALT) was performed to access the use level probability Weibull curves and reliability were calculated for the completion of a mission of 100,000 cycles at 300 to 1200 N. RESULTS All ceramics showed a high probability of survival (87-99%) at 300 N, irrespective of thickness. 3Y-TZP shows no significant decrease in the probability of survival up to 1200 N (83-96%). Lithium disilicate presented lower reliability than zirconia under the 600 N mission. 5Y-TZP showed lower reliability than 3Y-TZP at 1200 N. There was no significant difference in the Weibull modulus (3.23-7.12). 3Y-TZP had the highest characteristic strength (2483-2972 N), followed by 5Y-TZP (1512-1547 N) and lithium disilicate (971-1154 N). CONCLUSION Zirconia ceramics have a high probability of survival (up to 900 N-load), while lithium disilicate survives up to 300 N load only, irrespective of the thickness (1.0 mm or 1.5 mm). CLINICAL RELEVANCE The probability of survival of posterior crowns made with zirconia ceramics resists extreme loads while glass ceramics resist normal chewing loads. In addition, crowns with thinner occlusal face showed sufficient mechanical behavior.
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Grants
- 2016/09640-0, 2012/19078-7, 2021/06730-7, EMU 2016/18818-8, 2019/08693-1 Fundação de Amparo à Pesquisa do Estado de São Paulo
- 2016/09640-0, 2012/19078-7, 2021/06730-7, EMU 2016/18818-8, 2019/08693-1 Fundação de Amparo à Pesquisa do Estado de São Paulo
- 2016/09640-0, 2012/19078-7, 2021/06730-7, EMU 2016/18818-8, 2019/08693-1 Fundação de Amparo à Pesquisa do Estado de São Paulo
- Finance Code 001 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
- Finance Code 001 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
- 307255/2021-2 Conselho Nacional de Desenvolvimento Científico e Tecnológico
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Affiliation(s)
- Gelson Luis Adabo
- School of Dentistry, Sao Paulo State University (Unesp), Araraquara, Sao Paulo, Brazil.
| | - Diogo Longhini
- School of Dentistry, Sao Paulo State University (Unesp), Araraquara, Sao Paulo, Brazil
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23
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Velho HC, da Rosa LS, Dapieve KS, Borges ALS, Pereira GKR, Venturini AB, Valandro LF. How does the occlusal contact region influence the mechanical fatigue performance and fracture region of monolithic lithium disilicate ceramic crowns? J Mech Behav Biomed Mater 2023; 140:105746. [PMID: 36878081 DOI: 10.1016/j.jmbbm.2023.105746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/23/2023] [Accepted: 02/26/2023] [Indexed: 03/05/2023]
Abstract
OBJECTIVE To characterize the effect of the occlusal contact region on the mechanical fatigue performance and on the fracture region of monolithic lithium disilicate ceramic crowns. MATERIALS AND METHODS Monolithic lithium disilicate ceramic crowns were machined in a CAD/CAM system and adhesively luted onto glass-fiber reinforced epoxy resin preparations with resin cement. The crowns were divided into three groups (n = 16) according to load application region (cusp tip: restricted to cusp tips; cusp plane: restricted to cuspal inclined plane; or mixed: associating tip cusp and cuspal inclined plane). The specimens were submitted to a cyclic fatigue test (initial load: 200 N; step-size: 100 N; cycles/step: 20,000; loading frequency: 20 Hz; load applicator: 6 mm or 40 mm diameter stainless steel) until observing cracks (1st outcome) and fracture (2nd outcome). The data were analyzed by the Kaplan-Meier + Mantel-Cox post-hoc tests for both outcomes (cracks and fracture). Finite element analysis (FEA), occlusal contact region, contact radii measurements, and fractographic analyzes were performed. RESULTS The mixed group presented worse fatigue mechanical behavior (550 N / 85.000 cycles) compared to the cuspal inclined plane group (656 N / 111,250 cycles) (p < 0.05) for the first crack outcome, while the cusp tip group was similar to both groups (588 N / 97,500 cycles) (p > 0.05). The mixed group had the worst fatigue behavior (1413 N / 253,029 cycles) in relation to the other groups (Cusp tip: 1644 N / 293,312 cycles; Cuspal inclined plane: 1631 N / 295,174 cycles) considering the crown fracture outcome (p < 0.05). FEA showed higher tensile stress concentration areas just below the load application region. In addition, loading on the cuspal inclined plane induced a higher tensile stress concentration in the groove region. The most prevalent type of crown fracture was the wall fracture. Groove fracture was observed in 50% of the loading specimens exclusively on the cuspal inclined plane. CONCLUSION Load application on distinct occlusal contact regions affects the stress distribution pattern and consequently the mechanical fatigue performance and fracture region of the monolithic lithium disilicate ceramic crowns. A combination of loading at distinct regions is recommended to promote better evaluation of the fatigue behavior of a restored set.
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Affiliation(s)
- Helder Callegaro Velho
- MSciD and Ph.D. Post-Graduate Program in Oral Sciences, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Lucas Saldanha da Rosa
- MSciD and Ph.D. Post-Graduate Program in Oral Sciences, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Kiara Serafini Dapieve
- MSciD and Ph.D. Post-Graduate Program in Oral Sciences, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Alexandre Luiz Souto Borges
- Department of Dental Materials and Prosthodontics, São Paulo State University, São José dos Campos, São Paulo, Brazil.
| | - Gabriel Kalil Rocha Pereira
- MSciD and Ph.D. Post-Graduate Program in Oral Sciences, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Andressa Borin Venturini
- MSciD and Ph.D. Post-Graduate Program in Oral Sciences, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Luiz Felipe Valandro
- MSciD and Ph.D. Post-Graduate Program in Oral Sciences, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
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Packaeser MG, Aragonez GC, Machado PS, Borges ALS, Pereira GKR, Valandro LF, Rippe MP. High-versus low-viscosity resin cements: Its effect on the load-bearing capacity under fatigue of a translucent zirconia. J Mech Behav Biomed Mater 2023; 142:105829. [PMID: 37068429 DOI: 10.1016/j.jmbbm.2023.105829] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/28/2023] [Accepted: 04/02/2023] [Indexed: 04/05/2023]
Abstract
The purpose of the present study was to characterize the elastic modulus and Poisson's ratio of a resin cement with distinct viscosities, and to evaluate their impact on the static and fatigue strength of a translucent zirconia (4Y-PSZ) after air-abrasion surface treatment. Bar-shaped specimens of two different viscosities of resin cement (high and low) were obtained (25 × 10 × 3 mm). Sonelastic and Maxwell principles tests were performed to determine the elastic modulus and Poisson's ratio of each resin cement. Disc-shaped specimens of 4Y-PSZ were made (Ø = 15 mm, 1.2 mm in thickness) for the mechanical tests and allocated into groups according to two factors: surface treatment (presence or absence of air-abrasion with alumina particles; 45 μm grain-size); cement (absence, low or high viscosity). The static (n = 10) and cyclical (n = 15) biaxial flexural strength tests were performed by piston-on-three-balls geometry. A fatigue strength test was executed (20 Hz, initial stress of 60 MPa [12% of the mean static biaxial flexural strength], followed by increments of 25 MPa [5% of the mean static biaxial flexural strength] at each step of 10,000 cycles until the failure). The obtained data were analyzed by Weibull analysis. Survival rates were tabulated by the Kaplan-Meier test. Complementary analyses of surface roughness, topography, cross-sectional interfacial zone, fractography, and zirconia crystalline content (X-ray diffraction) were also performed. The evaluated resin cements with high and low viscosity presented similar elastic modulus (13.63 GPa; 12.74 GPa) and Poisson's ratio (0.32; 0.30), respectively. The air-abraded groups depicted higher mechanical strength of the zirconia ceramics than non-abraded groups (p˂ 0.05), regardless of the resin cement. 4Y-PSZ adhesively bonded to a high or low viscosity resin cement have statistically similar behavior (p˃ 0.05). The mechanical structural reliability of the 4Y-PSZ was not affected by the factors. Therefore, resin cement with high and low viscosity presented similar properties and potential to fill the zirconia surface, and did not affect the mechanical behavior of 4Y-PSZ. However, the air-abrasion surface treatment increased the static and fatigue flexural strength of the translucent zirconia.
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Dapieve KS, Velho HC, da Rosa LS, Pivetta JP, Maidana FC, Venturini AB, Kleverlaan CJ, Pereira GKR, Valandro LF. Ceramic surface conditioning, resin cement viscosity, and aging relationships affect the load-bearing capacity under fatigue of bonded glass-ceramics. J Mech Behav Biomed Mater 2023; 139:105667. [PMID: 36657192 DOI: 10.1016/j.jmbbm.2023.105667] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 01/03/2023] [Accepted: 01/05/2023] [Indexed: 01/09/2023]
Abstract
This study aimed to evaluate the influence of ceramic surface treatments, resin cement viscosities, and storage regimens on the fatigue performance of bonded glass-ceramics (lithium disilicate, LD; feldspathic, FEL). Ceramic discs (Ø = 10 mm; thickness = 1.5 mm) were allocated into eight groups per ceramic (n = 15), considering three factors: "ceramic surface treatment" in two levels - 5% hydrofluoric acid etching and silane-based coupling agent application (HF), or self-etching ceramic primer (E&P); "resin cement viscosity" in two levels - in high or low viscosity; and "storage regimen" in two levels - baseline, 24 h to 5 days; or aging, 180 days + 25,000 thermal cycles. Adhesive luting was performed onto glass fiber-reinforced epoxy resin discs (Ø = 10 mm; thickness = 2 mm) and the bonded assemblies were subjected to cyclic fatigue tests: initial load = 200 N; step-size = 25 N (FEL) and 50 N (LD); 10,000 cycles/step; 20 Hz. Scanning electron microscopy (SEM) inspections were performed. Regarding the LD ceramic, the fatigue behavior was reduced after aging for HF_HIGH and E&P_LOW conditions, while stable performance was observed for HF_LOW and E&P_HIGH. Regarding the FEL results, aging negatively affected HF_HIGH, E&P_HIGH, and E&P_LOW, being that only the HF_LOW condition presented a stable behavior. The failure initiated from defects on the etched surface of the ceramics, where the cross-sectional analysis commonly revealed unfilled areas. Long-term aging might induce a decrease in mechanical behavior. The 'ceramic microstructure/surface conditioning/resin cement viscosity relationships' modulate the fatigue performance of lithium disilicate and feldspathic glass-ceramics.
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Affiliation(s)
- Kiara Serafini Dapieve
- Post-Graduate Program in Oral Sciences, Prosthetic Dentistry Unit, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Helder Callegaro Velho
- Post-Graduate Program in Oral Sciences, Prosthetic Dentistry Unit, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Lucas Saldanha da Rosa
- Post-Graduate Program in Oral Sciences, Prosthetic Dentistry Unit, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Jordana Pavanelo Pivetta
- Post-Graduate Program in Oral Sciences, Prosthetic Dentistry Unit, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Fernanda Cocco Maidana
- Post-Graduate Program in Oral Sciences, Prosthetic Dentistry Unit, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Andressa Borin Venturini
- Post-Graduate Program in Oral Sciences, Prosthetic Dentistry Unit, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Cornelis Johannes Kleverlaan
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, North-Holland, the Netherlands.
| | - Gabriel Kalil Rocha Pereira
- Post-Graduate Program in Oral Sciences, Prosthetic Dentistry Unit, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Luiz Felipe Valandro
- Post-Graduate Program in Oral Sciences, Prosthetic Dentistry Unit, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
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Pilecco RO, Zucuni CP, Carvalho ABGD, Saavedra GDSFA, Marinho RMDM, Rocha Pereira GK, Valandro LF. Polishing the bonding surface, before or after crystallization, does not alter the fatigue behavior of bonded CAD-CAM lithium disilicate. J Mech Behav Biomed Mater 2023; 142:105794. [PMID: 37037152 DOI: 10.1016/j.jmbbm.2023.105794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 03/17/2023] [Accepted: 03/19/2023] [Indexed: 04/08/2023]
Abstract
The aim of this study was to assess if the finishing/polishing of the bonding surface of lithium disilicate ceramic, prior to or after crystallization, would affect the fatigue behavior of a bonded restorations. For this, lithium disilicate ceramic (IPS e.max CAD) discs (n = 15) were milled and randomly divided into 3 groups: CAD-CAM group which remained untouched; PRE group which received a finishing/polishing protocol (OptraFine system) prior to its crystallization; and POST group, which received the treatment after its crystallization. After surface treatments, ceramic and glass-fiber reinforced epoxy resin discs were paired and bonded using a resin cement (Multilink N). A cyclical fatigue test was conducted (frequency 20 Hz, initial load 200 N for 5000 cycles, step-size of 100 N for 10,000 cycles/step) until failure occurrence. Surface roughness and topography were analyzed. An initial descriptive analysis of surface roughness, FFL and CFF was performed to obtain the mean, standard deviation and confidence interval values (SPSS v. 21, SPSS Inc.) for statistical analysis. Roughness data was using one-way ANOVA with Tukey's post hoc test (α = 0.05), while the fatigue data was submitted to survival analysis with Kaplan-Meier test (α = 0.05) and Weibull modulus (Weibull++, Reliasoft). Neither the finishing/polishing procedure of the bonding surface, nor the moment (prior to or after crystallization), affected the fatigue behavior of bonded milled lithium disilicate. There were also no differences for mechanical reliability among conditions. Despite this, finishing/polishing reduced surface roughness and led to smoother topography. Finishing/polishing the bonding surface of milled lithium disilicate, before or after crystallization, does not alter the fatigue behavior of the bonded restorative set, although there is some influence on roughness and topography.
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Influence of thermo-mechanical aging on fracture resistance and wear of digitally standardized chairside computer-aided-designed/computer-assisted-manufactured restorations. J Dent 2023; 130:104450. [PMID: 36773741 DOI: 10.1016/j.jdent.2023.104450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 01/24/2023] [Accepted: 02/08/2023] [Indexed: 02/11/2023] Open
Abstract
OBJECTIVES To investigate the influence of thermal cycling and mechanical loading (TCML) aging on fracture resistance and wear behavior of various chairside computer-aided-designed/computer-assisted-manufactured (CAD/CAM) premolar crowns cemented on standardized tooth abutments. METHODS Eighty chairside CAD/CAM crowns were prepared using lithium disilicate (IPS e.max CAD; EM), zirconia-infiltrated lithium silicate (Celtra Duo; CD), polymer-infiltrated ceramic network (Vita Enamic; VE), and resin nanoceramics (Cerasmart; CS) (n = 20). The specimens were divided into two groups (n = 10). In one group, they were subjected to TCML: thermocycling (6000 cycles in distilled water at 5-55 °C) and mechanical loading (50 N for 1.2 × 106 cycles), while in control group they were stored in distilled water (37 °C for 24 h). The fracture load, height loss, and volume wear of the crowns were measured after TCML. Fractography was performed on fractured specimens. Data were analyzed using analysis of variance and multiple comparison tests (α=0.05). RESULTS The mean fracture loads of EM and CD were significantly higher than those of EC and CS (p<0.05). There was no significant change in the fracture load of any CAD/CAM crowns after TCML (p>0.05). CS exhibited a significantly higher volume wear than the other materials investigated. The wear tracts of all TCML crowns acted as failure origins during the fracture test. CONCLUSIONS The fracture resistance of glass-ceramic CAD/CAM crowns was significantly higher than that of resin composite crowns. A 5-year TCML aging did not affect the fracture resistance of CAD/CAM crowns investigated. However, TCML treatment produces a larger wear track in CS than in other materials. CLINICAL SIGNIFICANCE Appropriate chairside CAD/CAM restorative material should be selected for successful clinical practice after considering the fracture and wear resistance of the crowns.
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da Rosa LS, Velho HC, Tribst JPM, Valandro LF, Kleverlaan CJ, Pereira GKR. Weak adhesion between ceramic and resin cement impairs the load-bearing capacity under fatigue of lithium disilicate glass-ceramic crowns. J Mech Behav Biomed Mater 2023; 138:105604. [PMID: 36509013 DOI: 10.1016/j.jmbbm.2022.105604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 11/28/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022]
Abstract
OBJECTIVE To evaluate the fatigue behavior of lithium disilicate crowns with a simplified anatomy against progressive cement/ceramic debonding scenarios. MATERIALS AND METHODS Lithium disilicate crowns were fabricated via CAD/CAM and luted onto a dentin analogue material using resin cement following the manufacturer's instructions. Then, the different crown regions were isolated with paraffin oil for the absence of chemical adhesion according to four experimental groups (n = 15): Shoulder; Shoulder + Axial; Fully isolated; and Control (no insulation/fully bonded). Load to failure tests (n = 3) were run to determine cyclic fatigue parameters, and the specimens were subsequently submitted to a cyclic fatigue test (n = 12) (initial load 200 N for 5000 cycles, step 100 N, 15,000 cycles/step, frequency 20 Hz) until cracks were observed, and later fracture. The data were analyzed by Kaplan-Meier + Mantel-Cox post-hoc tests for both outcomes (cracks and fracture). Fractographic, cross-sectional surface, and finite element (FEA) analyzes were performed. RESULTS When it comes to crack occurrence when the chemical adhesion to the occlusal surface is compromised, there is worsening (p < 0.05) in fatigue behavior compared to groups where the occlusal portion of the crown is still bonded. Considering fracture occurrence, there was no difference (p > 0.05) among the tested groups. All cracks occurred in the occlusal portion, first as a radial crack at the ceramic intaglio surface, and posteriorly unleashing a Hertzian cone crack at the top surface, resulting in fractures on the frontal walls. The interface analysis showed no interference of the insulating agent. FEA showed that as the isolated areas increased, there was also an increase in both tensile and shear stresses concentration in the crown and in the cement layer. CONCLUSION The chemical adhesion between cement and ceramic is essential for better fatigue behavior of lithium disilicate crowns with a simplified anatomy, especially in the occlusal portion, but the restoration performance is impaired when such adhesion is compromised. There is an increase in crown and cement stress concentration with the progressive loss of chemical bonding of the crown's walls.
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Affiliation(s)
- Lucas Saldanha da Rosa
- MSciD and PhD Post-Graduate Program in Oral Sciences, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil.
| | - Helder Callegaro Velho
- MSciD and PhD Post-Graduate Program in Oral Sciences, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil.
| | - João Paulo Mendes Tribst
- Academic Centre for Dentistry Amsterdam (ACTA), Department of Oral Regenerative Medicine, University of Amsterdam and Vrije Universiteit Amsterdam, 1081 LA, Amsterdam, the Netherlands.
| | - Luiz Felipe Valandro
- MSciD and PhD Post-Graduate Program in Oral Sciences, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil.
| | - Cornelis Johannes Kleverlaan
- Academic Centre for Dentistry Amsterdam (ACTA), Department of Dental Material Sciences, University of Amsterdam and Vrije Universiteit Amsterdam, 1081 LA, Amsterdam, the Netherlands.
| | - Gabriel Kalil Rocha Pereira
- MSciD and PhD Post-Graduate Program in Oral Sciences, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil.
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A brief review on fatigue test of ceramic and some related matters in Dentistry. J Mech Behav Biomed Mater 2023; 138:105607. [PMID: 36549251 DOI: 10.1016/j.jmbbm.2022.105607] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 11/28/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022]
Abstract
The characteristics of dental ceramics have been extensively studied over the years to provide highly qualified materials for use in prosthetic restorations. The ability to adhere to dental substrates, outstanding aesthetics (translucency, color, and substrate masking ability) and improved mechanical properties provide these materials with optical features and high strength to withstand masticatory stimuli. Different classifications are adopted, and it is generally considered that glass-ceramics have better optical characteristics due to the high glass content, and polycrystalline ceramics have superior strength favored by their densified and organized crystals, hampering crack growth. This knowledge was largely built-up during years of scientific research through different testing methodologies, but mainly employing static loads. It is important to not only take into account the intensity of loads that these materials will be exposed to, but also the effect of the intermittence of cyclic load application leading to mechanical fatigue and the influence of factors related to the crack origin and their propagation under this condition. Furthermore, the bonding surface of ceramic restorations requires surface treatments that improve the bond strength to luting agents; however, these treatments require caution because of their potential to produce defects and affect the structural behavior. Moreover, ceramic restorations often require internal adjustments for proper seating or external adjustments for fitting the occlusal contact with the antagonist. In this sense, finishing/polishing protocols may alter the defect population, as luting agents may also interact by filling in the superficial defects on the restoration intaglio surface. Thus, the balance among all these factors will define the performance of a restorative setup, as well as the posterior exposure to the humid environment and the masticatory stimuli (cyclical loading), which may favor developing slow and subcritical growth of cracks in ceramic materials and the degradation of the bond interface. Therefore, it is essential that the concepts which explain the fatigue mechanism are understood, as well as the crack propagation and failure patterns of restorative ceramic materials.
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Noronha MDS, Carvalho MAD, Do AQ, Neto VGDA, Campos CH, Giannini M, Magne P. Effect of thickness and CAD-CAM material on fatigue resistance of endodontically treated molars restored with occlusal veneers. J Prosthodont 2023; 32:e19-e29. [PMID: 36087111 DOI: 10.1111/jopr.13606] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 09/06/2022] [Indexed: 11/30/2022] Open
Abstract
PURPOSE To evaluate the influence of the thickness and type of computer-aided design and computer-aided manufacturing (CAD-CAM) material on the fatigue resistance and failure mode of endodontically treated teeth (ETT) restored with occlusal veneers (OV). MATERIALS AND METHODS Seventy-five (N = 75) ETT were restored with Herculite XRV in the endodontic access. Five experimental groups (n = 15) were tested. Four groups had two different thicknesses (0.6-0.7 mm or 1.4-1.6 mm) and two different CAD-CAM materials: zirconia-reinforced lithium-silicate (LS/Celtra Duo) and composite resin (RC/Cerasmart). The fifth group (control) did not have occlusal veneers. All the specimens were subjected to accelerated fatigue (5 Hz frequency) with an occlusal load increasing up to 1800 N and 131,000 cycles. The number of cycles was recorded when the machine stopped or at the completion of the test. Fatigue resistance was analyzed using the Kaplan-Meier survival test (95% significance level, log-rank post hoc pairwise comparisons). The samples were categorized according to failure mode. The CAD-CAM materials were examined through scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). RESULTS No differences were found between the thicknesses, regardless of the type of the CAD-CAM material. The thick LS OV outperformed the RC and control groups. The thin RC OV and control groups showed a higher percentage of repairable and possibly repairable failures than the other groups. LS was more homogeneous under SEM, and the EDS analysis detected Si and Zr, but not Li. CONCLUSIONS A larger thickness did not improve the resistance of the CAD-CAM materials. Thick LS showed a higher cumulative survival rate to fatigue than the RC and control groups. The direct composite alone (control) survived similarly to the experimental groups, except for the thick LS.
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Affiliation(s)
- Mayara Dos Santos Noronha
- Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas, São Paulo, Brazil
| | | | - Anh Quynh Do
- Advanced Endodontics, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA
| | | | - Camila Heitor Campos
- Department of Oral Rehabilitation, School of Dentistry, Federal Fluminense University, Nova Friburgo, Brazil
| | - Marcelo Giannini
- Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas, São Paulo, Brazil
| | - Pascal Magne
- Division of Restorative Sciences, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA
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Lana TMDSD, Weber KR, Medeiros JA, Goedel F, Benetti P, Borba M. Fatigue-life and stress distribution of a glass-ceramic under different loading conditions. Braz Dent J 2023; 34:80-88. [PMID: 36888848 PMCID: PMC10027096 DOI: 10.1590/0103-6440202305129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 11/17/2022] [Indexed: 03/08/2023] Open
Abstract
This study aimed to evaluate the effect of different loading conditions on the mechanical behavior and stress distribution of a leucite-reinforced glass-ceramic. Plate-shaped ceramic specimens were obtained from leucite-reinforced glass-ceramic (1.5 × 8.4 × 8.3 mm) and adhesively cemented to a dentin analog substrate. Monotonic and cyclic contact fatigue tests were performed to simulate sphere-to-flat contact, using a 6 mm diameter spherical piston; and flat-to-flat contact, using a 3 mm diameter flat piston. For the monotonic test (n=20), a gradual compressive load (0.5 mm/min) was applied to the specimen using a universal testing machine. Failure load data were analyzed with Weibull statistics. The cyclic contact fatigue test was performed using protocols (load and a number of cycles) defined by the boundary technique (n=30). Fatigue data were analyzed using an inverse power law relationship and Weibull-lifetime distribution. The stress distribution was investigated using Finite Element Analysis (FEA). The monotonic and the fatigue Weibull modulus were similar among the two contact conditions. In fatigue, the slow crack growth exponent was greater for sphere-to-flat contact, which indicates that the load level had a greater effect on the specimen's probability of failure. In conclusion, FEA showed different stress distribution for the tested loading conditions. The stress distribution and probability of fatigue failure of specimens tested in sphere-to-flat contact showed greater dependency to load level.
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Affiliation(s)
| | - Kátia Raquel Weber
- Graduate Program in Dentistry, Dental School, University of Passo Fundo(UPF), Passo Fundo, Rio Grande do Sul, Brazil
| | - Juliana Arisi Medeiros
- Graduate Program in Dentistry, Dental School, University of Passo Fundo(UPF), Passo Fundo, Rio Grande do Sul, Brazil
| | - Fábio Goedel
- Engineering School, University of Passo Fundo(UPF), Passo Fundo, Rio Grande do Sul, Brazil
| | - Paula Benetti
- Graduate Program in Dentistry, Dental School, University of Passo Fundo(UPF), Passo Fundo, Rio Grande do Sul, Brazil
| | - Márcia Borba
- Graduate Program in Dentistry, Dental School, University of Passo Fundo(UPF), Passo Fundo, Rio Grande do Sul, Brazil
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Chen Y, Maghami E, Bai X, Huang C, Pow EHN, Tsoi JKH. Which dentine analogue material can replace human dentine for crown fatigue test? Dent Mater 2023; 39:86-100. [PMID: 36503862 DOI: 10.1016/j.dental.2022.11.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 11/19/2022] [Accepted: 11/25/2022] [Indexed: 12/13/2022]
Abstract
OBJECTIVE To seek dentine analogue materials in combined experimental, analytical, and numerical approaches on the mechanical properties and fatigue behaviours that could replace human dentine in a crown fatigue laboratory test. METHODS A woven glass fibre-filled epoxy (NEMA grade G10; G10) and a glass fibre-reinforced polyamide-nylon (30% glass fibre reinforced polyamide-nylon 6,6; RPN) were investigated and compared with human dentine (HD). Flexural strength and elastic modulus (n = 10) were tested on beam-shaped specimens via three-point bending, while indentation hardness (n = 3) was tested after fracture. Abutment substrates of G10, RPN and HD were prepared and resin-bonded with monolithic lithium disilicate crowns (n = 10), then subjected to wet cyclic loading in a step-stress manner (500 N initial load, 100 N step size, 100,000 cycles per step, 20 Hz frequency). Data were statistically analysed using Kruskal-Wallis one-way ANOVA followed by post-hoc comparisons (α = 0.05). Survival probability estimation was performed by Mantel-Cox Log-Rank test with 95% confidence intervals. The fatigue failure load (FFL) and the number of cycles until failure (NCF) were evaluated with Weibull statistics. Finite Element Models of the fatigue test were established for stress distribution analysis and lifetime prediction. Fractographic observations were qualitatively analysed. RESULTS The flexural strength of HD (164.27 ± 14.24 MPa), G10 (116.48 ± 5.93 MPa), and RPN (86.73 ± 3.56 MPa) were significantly different (p < 0.001), while no significant difference was observed in their flexural moduli (p = 0.377) and the indentation hardness between HD and RPN (p = 0.749). The wet cyclic fatigue test revealed comparable mean FFL and NCF of G10 and RPN to HD (p = 0.237 and 0.294, respectively) and similar survival probabilities for the three groups (p = 0.055). However, RPN promotes higher stability and lower deviation of fatigue test results than G10 in Weibull analysis and FEA. SIGNIFICANCE Even though dentine analogue materials might exhibit similar elastic properties and fatigue performance to human dentine, different reliabilities of fatigue on crown-dentine analogues were shown. RPN seems to be a better substrate that could provide higher reliability and predictability of laboratory study results.
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Affiliation(s)
- Yanning Chen
- Dental Materials Science, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - Ebrahim Maghami
- Department of Mechanical Engineering and Mechanics, College of Engineering, Drexel University, Philadelphia, PA 19104, USA
| | - Xuedong Bai
- Dental Materials Science, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - Cui Huang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory for Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Edmond Ho Nang Pow
- Prosthodontics, Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - James Kit Hon Tsoi
- Dental Materials Science, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China.
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İrem DÖ, Cömert ZY, Alpkılıç DŞ, Keleşoğlu E, İşler Değer S. The Effect of Preceramic Soldering on Fracture Resistance of 4-Unit Zirconia Fixed Dental Prostheses. J Prosthodont 2022; 31:815-821. [PMID: 35118772 DOI: 10.1111/jopr.13488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 01/25/2022] [Indexed: 01/04/2023] Open
Abstract
PURPOSE Preceramic soldering of zirconia may deliver better fitting restorations. However, there is not sufficient evidence regarding the influence of preceramic soldering of zirconia restorations on mechanical strength. The aim of this study was to evaluate the effect of preceramic soldering on the fracture load of 4-unit zirconia fixed dental prostheses (FDPs). MATERIALS AND METHODS Eighty samples of 4-unit FDPs between maxillary right first premolar and maxillary right second molar were prepared and two restorative materials were used as a framework (Z) and monolithic restoration (M). The samples were divided into two subgroups as control (C) and study (S). The restorations of study groups (S) were divided into two pieces and soldered with a bonding material (DCM HotBond Zirkon). The groups were divided into two subgroups for thermal cycle (T) application. After soldering and thermal cycling application, 4-point bending test was applied to the samples at a cross-head speed of 1 mm/min in a universal testing machine and the fracture load was recorded. The data was analyzed statistically, and the level of significance was set at α = 0.001. RESULTS Statistically significant differences were found among the groups, based on the results of maximum failure loads (p < 0.001). The highest mean failure load was observed in the ZCT(-) group (1094.1 + 139.77 N), while the lowest mean failure load was obtained in the ZST(+) group (627.7 + 82.14 N). No significant difference was found among the groups MC and MS, MC, and ZC groups (p > 0.001). Thermal aging application caused lower fracture resistance in control and soldering groups (p < 0.001). CONCLUSIONS The preceramic soldering applications affected zirconia group negatively. However, the values were above the clinically acceptable static load bearing capacity for posterior teeth. Soldering did not cause a statistically significant difference for the fracture strengths of monolithic zirconia groups. Thermal cycling affected the fracture strength of zirconia and monolithic zirconia restorations negatively.
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Affiliation(s)
| | | | - Dilara Şeyma Alpkılıç
- Department of Prosthodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
| | - Ergün Keleşoğlu
- Faculty of Materials Science and Technologies, Turkish-German University, Istanbul, Turkey
| | - Sabire İşler Değer
- Department of Prosthodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
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Alves LMM, Rodrigues CDS, Ramos NDC, Buizastrow J, Campos TMB, Bottino MA, Zhang Y, Melo RMD. Silica infiltration on translucent zirconia restorations: Effects on the antagonist wear and survivability. Dent Mater 2022; 38:2084-2095. [PMID: 36446649 PMCID: PMC9928576 DOI: 10.1016/j.dental.2022.11.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 09/23/2022] [Accepted: 11/11/2022] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To assess potential antagonist wear and survival probability of silica-infiltrated zirconia compared to glass-graded, glazed, and polished zirconia. METHODS Table top restorations made of 3Y-TZP (3Y), 5Y-PSZ (5Y), and lithium disilicate (LD) were bonded onto epoxy resin preparations. Each zirconia was divided into five groups according to the surface treatment: polishing; glaze; polishing-glaze; glass infiltration; and silica infiltration. The LD restorations received a glaze layer. Specimens were subjected to sliding fatigue wear using a steatite antagonist (1.25 ×106 cycles, 200 N). The presence of cracks, fractures, and/or debonding was checked every one/third of the total number of cycles was completed. Roughness, microstructural, Scanning electron microscopy, wear and residual stress analyses were conducted. Kaplan-Meier, Mantel-Cox (log-rank) and ANOVA tests were performed for statistical analyses. RESULTS The survival probability was different among the groups. Silica infiltration and polishing-glaze led to lower volume loss than glaze and glass-infiltration. Difference was observed for roughness among the zirconia and surface treatment, while lithium disilicate presented similar roughness compared to both glazed zirconia. Scanning electron microscopy revealed the removal of the surface treatment after sliding fatigue wear in all groups. Compressive stress was detected on 3Y surfaces, while tensile stress was observed on 5Y. SIGNIFICANCE 3Y and 5Y zirconia behaved similarly regarding antagonist wear, presenting higher antagonist wear than the glass ceramic. Silica-infiltrated and polished-glazed zirconia produced lower antagonist volume loss than glazed and glass-infiltrated zirconia. Silica-infiltrated 3Y and lithium disilicate restorations were the only groups to show survival probabilities lower than 85%.
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Affiliation(s)
- Larissa Marcia Martins Alves
- Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology, Av. Eng. Francisco José Longo, 777, Jardim São Dimas, 12245-000 São José dos Campos, SP, Brazil; Department of Biomaterials and Biomimetics, New York University College of Dentistry, 433 1st Ave., New York, NY 10010, United States
| | - Camila da Silva Rodrigues
- Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology, Av. Eng. Francisco José Longo, 777, Jardim São Dimas, 12245-000 São José dos Campos, SP, Brazil; Department of Biomaterials and Biomimetics, New York University College of Dentistry, 433 1st Ave., New York, NY 10010, United States
| | - Nathalia de Carvalho Ramos
- Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology, Av. Eng. Francisco José Longo, 777, Jardim São Dimas, 12245-000 São José dos Campos, SP, Brazil
| | - Jeff Buizastrow
- Department of Biomaterials and Biomimetics, New York University College of Dentistry, 433 1st Ave., New York, NY 10010, United States
| | - Tiago Moreira Bastos Campos
- Department of Physics, Aeronautics Technological Institute (ITA), Praça Marechal Eduardo Gomes, 50, 12228-900 São José dos Campos, SP, Brazil
| | - Marco Antonio Bottino
- Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology, Av. Eng. Francisco José Longo, 777, Jardim São Dimas, 12245-000 São José dos Campos, SP, Brazil
| | - Yu Zhang
- Department of Preventive and Restorative Sciences, School of Dental Medicine, University of Pennsylvania, PA 19104, United States
| | - Renata Marques de Melo
- Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology, Av. Eng. Francisco José Longo, 777, Jardim São Dimas, 12245-000 São José dos Campos, SP, Brazil.
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Souza LFB, da Rosa LS, Menna Barreto VS, Ribeiro VF, Fraga S, Kleverlaan CJ, Valandro LF, Pereira GKR. Pigmentation techniques of a 4YSZ: Effect on the fatigue mechanical behavior of a 4YSZ adhesively luted onto dentin analog. Dent Mater 2022; 38:2003-2013. [DOI: 10.1016/j.dental.2022.11.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 11/04/2022] [Accepted: 11/11/2022] [Indexed: 11/23/2022]
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Connector design effects on the in vitro fracture resistance of 3-unit monolithic prostheses produced from 4 CAD-CAM materials. J Prosthet Dent 2022; 128:1319.e1-1319.e10. [DOI: 10.1016/j.prosdent.2022.09.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 09/26/2022] [Accepted: 09/27/2022] [Indexed: 11/06/2022]
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Tsujimoto A, Barkmeier WW, Teixeira EC, Takamizawa T, Miyazaki M, Latta MA. Fatigue bond strength of dental adhesive systems: Historical background of test methodology, clinical considerations and future perspectives. JAPANESE DENTAL SCIENCE REVIEW 2022; 58:193-207. [PMID: 35789771 PMCID: PMC9250030 DOI: 10.1016/j.jdsr.2022.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 01/27/2022] [Accepted: 05/09/2022] [Indexed: 10/31/2022] Open
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Ruggiero MM, Gomes RS, Bergamo ETP, Freitas MIM, Bonfante EA, Del Bel Cury AA. Marginal and Internal Misfit of Occlusal Veneers Made in Resin-matrix Ceramics. Oper Dent 2022; 47:701-708. [DOI: 10.2341/21-115-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/25/2022] [Indexed: 11/30/2022]
Abstract
SUMMARY
Objective
Considering that misfit is a significant predictor of the clinical success of indirect restorations, the objective of this study was to evaluate the marginal and internal misfit of two computer-aided design and manufacturing (CAD/CAM) RMC ceramic materials used as occlusal veneers (OVs) of different thicknesses.
Methods and Materials
A CAD model of a mandibular first molar was obtained and OV preparations 0.5-, 1.0-, and 1.5-mm thick were modeled and milled in two different materials (n=10/group): resin nanoceramic (RNC) and polymer-infiltrated ceramic network (PICN). Using the same CAD model, tooth preparations were milled in fiber-reinforced epoxy resin (n=20/thickness). The marginal and internal misfit of the restorations was assessed by X-ray microtomography. The measurements of the marginal gap (MG) and absolute marginal discrepancy were performed in two locations on each slice, whereas internal gap (IG) measurements were performed at ten locations on each slice. The data obtained were analyzed using two-way analysis of variance and Tukey post-hoc tests (α=0.05).
Results
No significant effect was attributable to the material type or material–thickness interaction for the MG, absolute marginal discrepancy (AMD), or IG (p>0.05). However, the thickness significantly affected the IG of the restorations (p<0.05). CAD/CAM RNC and PICN systems presented similar MG and AMD for OVs 0.5-, 1.0-, and 1.5-mm thick. However, the IG varied between thicknesses.
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Affiliation(s)
- MM Ruggiero
- Mirelle Maria Ruggiero, DDS, MSc, Department of Prosthodontics and Periodontology, University of Campinas -Piracicaba Dental School, Piracicaba, SP, Brazil
| | - RS Gomes
- Rafael Soares Gomes, DDS, MSc, PhD, Department of Prosthodontics and Periodontology, University of Campinas -Piracicaba Dental School, Piracicaba, SP, Brazil
| | - ETP Bergamo
- Edmara Tatiely Pedroso Bergamo, DDS, MSc, PhD, Department of Prosthodontics and Periodontology, University of São Paulo - Bauru School of Dentistry, Bauru, SP, Brazil
| | - MIM Freitas
- Mariana Itaborai Moreira Freitas, DDS, MSc, Department of Prosthodontics and Periodontology, University of Campinas -Piracicaba Dental School, Piracicaba, SP, Brazil
| | - EA Bonfante
- Estevam Augusto Bonfante, DDS, MSc, PhD, Department of Prosthodontics and Periodontology, University of São Paulo -Bauru School of Dentistry, Bauru, SP, Brazil
| | - AA Del Bel Cury
- *Altair Antoninha Del Bel Cury, DDS, MSc, PhD, Department of Prosthodontics and Periodontology, University of Campinas - Piracicaba Dental School, Piracicaba, SP, Brazil
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Ferreira MC, Alessandretti R, Pereira GKR, Bacchi A, Maroli A, Gomes ÉA, Spazzin AO. Do preheated composite resin or adhesive resin layer strengthen the feldspar ceramic? J Prosthet Dent 2022:S0022-3913(22)00510-8. [PMID: 36202633 DOI: 10.1016/j.prosdent.2022.08.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 08/17/2022] [Accepted: 08/18/2022] [Indexed: 11/06/2022]
Abstract
STATEMENT OF PROBLEM Preheated composite resin and adhesive coating have been recommended as luting agents for ceramic veneers; however, information about the mechanical behavior of feldspathic porcelain veneers after using these methods is still limited. PURPOSE The purpose of this in vitro study was to evaluate the influence of the use of preheated composite resin or an adhesive resin layer on the strengthening of a feldspathic porcelain. MATERIAL AND METHODS Feldspathic porcelain disks were fabricated (N=210), etched (10% hydrofluoric acid for 90 seconds), and bonded according to resin-based luting agents (30 per group) for the biaxial flexural strength tests: photopolymerized resin cement, flowable composite resin, preheated composite resin, with or without previous adhesive coating. Characteristic strength and Weibull modulus were calculated. The viscosity of the luting agents was measured by using isothermal analyses. Finite element analysis simulated the flexural test. Fractographic and bonded interfaces were observed. RESULTS The use of preheated composite resin led to the lowest stress levels in the feldspathic porcelain veneers. However, it did not increase the ceramic strengthening compared with other luting agents, as higher values were observed with flowable composite resin (P<.05). The use of an adhesive resin layer had no significant effect on ceramic strengthening when associated with preheated composite resin or resin cement (P>.05). Preheated composite resin presented the highest viscosity and led to incomplete filling of the porcelain surface irregularities. Failures originated on the ceramic surface subjected to tensile stress and were typically associated with pores at the ceramic-luting agent interface. CONCLUSIONS The use of preheated composite resin or an adhesive resin layer did not have a positive effect on strengthening feldspathic porcelain.
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Affiliation(s)
- Michele C Ferreira
- Professor, School of Dentistry, Meridional Faculty, ATITUS, Passo Fundo, Rio Grande do Sul, Brazil; Post-Graduate student Program in Dentistry, School of Dentistry, University of Ribeirão Preto, UNAERP, Ribeirão Preto, São Paulo, Brazil
| | - Rodrigo Alessandretti
- Professor, MSciD Post-Graduate Program in Dentistry, School of Dentistry, Meridional Faculty - IMED, Passo Fundo, Rio Grande do Sul, Brazil
| | - Gabriel K R Pereira
- Professor, MSciD-PhD Post-Graduate Programs in Oral Science, Prosthodontics Units, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul, Brazil
| | - Ataís Bacchi
- Professor, MSciD Post-Graduate Program in Dentistry, Paulo Picanço School of Dentistry - FACPP, Fortaleza, Ceará, Brazil
| | - Angélica Maroli
- Professor, School of Dentistry, Meridional Faculty - ATITUS, Passo Fundo, Rio Grande do Sul, Brazil
| | - Érica A Gomes
- Professor, MsciD Post-Graduate Program in Dentistry, School of Dentistry, University of Ribeirão Preto - UNAERP, Ribeirão Preto, São Paulo, Brazil
| | - Aloísio O Spazzin
- Professor, MSciD Post-Graduate Program in Dentistry, School of Dentistry, Meridional Faculty - ATITUS, Passo Fundo, Rio Grande do Sul, Brazil.
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Velho HC, da Rosa LS, Temp RW, Cocco FM, Pereira GKR, May LG, Valandro LF. Adhesive application after ceramic surface treatment is detrimental to load-bearing capacity under fatigue of a lithium disilicate glass-ceramic. J Mech Behav Biomed Mater 2022; 135:105453. [PMID: 36126505 DOI: 10.1016/j.jmbbm.2022.105453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 08/30/2022] [Accepted: 09/03/2022] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To evaluate whether an adhesive application after surface treatment on a lithium disilicate ceramic (LD) has an influence on its load-bearing capacity under fatigue. METHODS LD discs (Ø= 10 mm; thickness= 1 mm) were allocated into 8 groups (n= 15), considering 3 factors: "ceramic surface treatment" - HF: hydrofluoric acid + universal primer application; or MEP: single-component ceramic primer; "adhesive application" - with or without; and "aging protocol" - baseline: 24 h to 7 days; or aging: 180 days of storage + 25,000 thermal cycles. The LD discs were adhesively bonded to glass fiber-reinforced epoxy resin discs (Ø= 10 mm; thickness= 2 mm) and stored according to the condition and each group. Cyclic fatigue testing (initial load= 100 N; step size= 100 N until600 N and after step size= 25 N to failure; 10,000 cycles/step; 20 Hz frequency) was performed. Fractographic and adhesive interface analyzes were also performed. The collected data were then analyzed by Kaplan Meier and Mantel-Cox tests and One-way ANOVA. RESULTS The adhesive application in the baseline condition had no influence on the load-bearing capacity under fatigue when the HF surface treatment was performed, however, adhesive application for the MEP treatment led to worse results than without it. The adhesive application in the aged condition showed worse fatigue outcomes for both treatments. All specimens presented radial cracks. MEP treatment followed by adhesive application presented the thickest luting layer. CONCLUSION The adhesive application after surface treatments of a lithium disilicate glass-ceramic is detrimental to its load-bearing capacity under fatigue when adhesively luted onto a supporting substrate.
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Affiliation(s)
- Helder Callegaro Velho
- Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Lucas Saldanha da Rosa
- Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Renatta Wrasse Temp
- Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Fernanda Maidana Cocco
- Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Gabriel Kalil Rocha Pereira
- Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Liliana Gressler May
- Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Luiz Felipe Valandro
- Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
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Guilardi LF, Pereira G, Giordani JC, Kleverlaan CJ, Valandro LF, Rippe MP. Cement Choice and the Fatigue Performance of Monolithic Zirconia Restorations. Oper Dent 2022; 47:461-472. [PMID: 35917240 DOI: 10.2341/20-143-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/21/2021] [Indexed: 11/23/2022]
Abstract
This study investigated the fatigue failure load of simplified monolithic yttria partially stabilized zirconia polycrystal restorations cemented to a dentin-like substrate using different luting systems. Disc-shaped ceramic (Zenostar T, 10 mm Ø × 0.7 mm thick) and dentin-like substrate (10 mm Ø × 2.8 mm thick) were produced and randomly allocated into eight groups, without or with thermocycling (TC=5-55°C/12,000×): "cement" (RelyX Luting 2 - glass ionomer cement [Ion], [Ion/TC]; RelyX U200 - self-adhesive resin cement [Self], [Self/TC]; Single Bond Universal+RelyX Ultimate - MDP-containing adhesive + resin cement [MDPAD + RC], [MDP-AD + RC/TC]; ED Primer II+Panavia F 2.0 - Primer + MDP-containing resin cement [PR + MDP-RC], [PR + MDP-RC/TC])). Each luting system was used as recommended by the manufacturer. Staircase methodology (20 Hz; 250,000 cycles) was applied for obtaining the fatigue failure loads. Fractographic characteristics were also assessed. At baseline, the Ion group presented the lowest fatigue load, although it was statistically similar to the Self group. The resin-based cement systems presented the highest fatigue performance, with the Ion group being only statistically equal to the Self group. Thermocycling influenced the groups differently. After aging, the MDP-AD + RC presented the highest mean, followed by the PR + MDP-RC and Self groups, while the Ion group had the lowest mean. Fractographic analysis depicted all failures as radial cracks starting at the zirconia intaglio surface. The luting system with MDP-containing adhesive applied prior to the resin cement presented the highest fatigue failure load after aging, presenting the best predictability of stable performance. Despite this, monolithic zirconia presents high load-bearing capability regardless of the luting agent.
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Affiliation(s)
- L F Guilardi
- Luis Felipe Guilardi, associate researcher, Post-Graduate Program in Oral Science (Prosthodontics Unit), Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil
| | - Gkr Pereira
- Gabriel Kalil Rocha Pereira, MsciD, PhD, adjunct professor, Post-Graduate Program in Oral Science (Prosthodontics Units), Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil
| | - J C Giordani
- João Carlos Giordani, undergraduate student, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil
| | - C J Kleverlaan
- Cornelis Johannes Kleverlaan, PhD, full professor, Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam, Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, Noord-Holland, The Netherlands
| | - L F Valandro
- Luiz Felipe Valandro, MSciD, PhD, full professor, Post-Graduate Program in Oral Science (Prosthodontics Units), Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil
| | - M P Rippe
- *Marilia Pivetta Rippe, MSciD, PhD, adjunct professor, Post-Graduate Program in Oral Science (Prosthodontics Units), Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil
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Effects of material and piston diameter on the fatigue behavior, failure mode, and stress distribution of feldspathic ceramic simplified restorations. J Mech Behav Biomed Mater 2022; 134:105398. [DOI: 10.1016/j.jmbbm.2022.105398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 07/16/2022] [Accepted: 07/20/2022] [Indexed: 11/21/2022]
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Thickness and internal adjustment of monolithic resin composite milled crowns: Effect on the load-bearing capacity under fatigue. J Mech Behav Biomed Mater 2022; 134:105407. [DOI: 10.1016/j.jmbbm.2022.105407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/23/2022] [Accepted: 07/26/2022] [Indexed: 11/24/2022]
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Souza LFB, Pilecco RO, Menna Barreto VS, Chiapinotto GF, Daudt NDF, Valandro LF, Pereira GKR. Pre-sintering pigmentation techniques do not affect the fatigue behavior of adhesively luted 4YSZ restorations. J Mech Behav Biomed Mater 2022; 132:105270. [PMID: 35617820 DOI: 10.1016/j.jmbbm.2022.105270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/05/2022] [Accepted: 05/11/2022] [Indexed: 11/20/2022]
Abstract
This study aims to characterize the effect of shading techniques on the fatigue behavior of a 4YSZ ceramic (4 mol% yttrium stabilized zirconia) adhesively bonded to a dentin analogue (fiber-reinforced epoxy resin). 4YSZ ceramic discs (IPS e.max ZirCAD, Ø = 10 mm and 1 mm of thickness) were allocated according to the factor 'shading technique' into 4 groups: Brush- unshaded ceramic disc (IPS e.max ZirCAD BL) pigmented at the pre-sintered stage with pigment solution applied manually using a round liner brush; Immersion- unshaded ceramic disc pigmented through immersion in the solution for 1 s on only one side of the ceramic disc; Manufacturer- specimens already shaded by the manufacturer (IPS e.max ZirCAD MT A2 - Manufacturer group); Control- a control condition with absence of pigment (i.e. non-pigmented specimens). The specimens were sintered and a spectrophotometer (SP60, EX- Rite) was used to ensure that the same perceived color (i.e. pigment saturation) was achieved in the different shading strategies (Manufacturer, Brush or Immersion groups). To do so, the color differences (ΔE00) were calculated using the CIEDE 2000 equation; and an ΔE00 of up to 1.77 was considered as an acceptability threshold. Dentin analogue discs were obtained (Ø = 10 mm and 2.5 mm of thickness) and randomly allocated into pairs with the 4YSZ ceramic discs. Next, the pairs were adhesively bonded using a resin cement (Multilink N). The bonded assemblies (n = 15) were tested for fatigue using the step-stress test method (frequency of 20 Hz; 10,000 cycles per step, initial load 200 N; step-size of 100 N, up to 700 N; and after, step-size of 50 N, until specimen failure/fracture or radial cracks). Fatigue failure load (FFL) and number of cycles for failure (CFF) were recorded for statistical analysis. Fractographic features were accessed, and complementary roughness, topography, grain size and phase content analyses were performed. No statistical differences were observed in the fatigue behavior among the non-shaded condition (Control group - 880 N) and the shaded specimens (Manufacturer - 887 N, Brush - 820 N, and Immersion - 850 N groups; p > 0.05). However, the use of a brush shading technique induced slightly inferior fatigue mechanical behavior of the restorative set compared to the specimens already shaded by the manufacturer (p = 0.027). No differences in Weibull modulus were observed among the tested groups. The specimens pigmented by the brush technique demonstrated a rougher surface, with statistically higher Rz values, in addition to a larger grain size in comparison to all other conditions (p< 0.05). No m-phase content was identified (only t and c phases were detected). Thus, the shading techniques used to provide a Vita classic A2 shade does not negatively affect the mechanical fatigue properties of a bonded 4YSZ ceramic. However, the brush technique has detrimental effect on the fatigue behavior compared to when the ceramic was already provided in a shaded format by its manufacturer.
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Affiliation(s)
- Luiza Freitas Brum Souza
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Rafaela Oliveira Pilecco
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | | | | | - Natália de Freitas Daudt
- MSciEng and PhD Post-Graduate Program in Mechanical Engineering, Faculty of Mechanical Engineering, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Luiz Felipe Valandro
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Gabriel Kalil Rocha Pereira
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
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Does adhesive luting promote improved fatigue performance of lithium disilicate simplified crowns? J Mech Behav Biomed Mater 2022; 134:105373. [PMID: 35868064 DOI: 10.1016/j.jmbbm.2022.105373] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 07/14/2022] [Indexed: 11/22/2022]
Abstract
The present study aimed to determine the influence of adhesive luting on the fatigue mechanical properties of simplified lithium disilicate crowns luted to dentin analogues preparations, and to compare two different approaches of simulation of a non-adhesive luting procedure. To this end, 30 prosthetic preparations of glass fiber-filled epoxy resin used as dentin analogues were milled and lithium disilicate crowns were pressed (1.5 mm thickness), which were allocated into three different groups: resin cement (RC), resin cement isolated by paraffin oil (RCI) and zinc phosphate cement (ZP). For luting procedures, the ceramic crowns of the RC and RCI groups had their internal surface treated with 5% hydrofluoric acid and universal primer. Afterwards, a thin layer of paraffin oil was applied onto the ceramic crown intaglio surface in the RCI group. The dentin analogues were treated with 10% hydrofluoric acid, followed by primer application and luting as recommended by the manufacturer. No previous surface treatments were performed for the ZP group, and the cement was applied as recommended. The fatigue test was run under cyclic fatigue (load 400-2000 N, step-size 100 N, 15,000 cycles/step, frequency 20 Hz) until failure detection (radial crack) by transillumination. The fatigue failure load (FFL), number of cycles until failure (CFF), and survival rate in each testing step were recorded. The RC group presented a higher FFL, CFF and survival rate compared to the other groups (p < 0.001), which were statistically equal to each other (p > 0.05). Weibull analysis detected no difference between groups for the Weibull module. Therefore, loss of adhesion between the evaluated substrates induces a significant reduction in load-bearing capacity under fatigue of the lithium disilicate crowns, strengthening the strong-importance of long-lasting adhesion for crown's survival. In addition, different methods for the simulation of non-adhesive conditions induce the same performance in the explored outcomes, confirming that both are valid approaches for laboratory studies.
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Ottoni R, Marocho SMS, Griggs JA, Borba M. CAD/CAM versus 3D-printing/pressed lithium disilicate monolithic crowns: adaptation and fatigue behavior. J Dent 2022; 123:104181. [DOI: 10.1016/j.jdent.2022.104181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 05/13/2022] [Accepted: 06/06/2022] [Indexed: 10/18/2022] Open
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Cadore-Rodrigues AC, Machry RV, Zucuni CP, Pereira GKR, Valandro LF. Grinding and polishing of the inner surface of monolithic simplified restorations made of zirconia polycrystals and lithium disilicate glass-ceramic: Effects on the load-bearing capacity under fatigue of the bonded restorations. J Mech Behav Biomed Mater 2021; 124:104833. [PMID: 34562764 DOI: 10.1016/j.jmbbm.2021.104833] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/01/2021] [Accepted: 09/07/2021] [Indexed: 10/20/2022]
Abstract
This study evaluated the effect of grinding and polishing the inner surface of monolithic discs made of zirconia polycrystals (ZR) and lithium disilicate glass-ceramic (LD) on the load-bearing capacity under fatigue of the restorations bonded onto a dentin analogue material (epoxy resin). ZR and LD ceramic discs (10 mm in diameter, 1 mm in thickness) were produced and randomly allocated into 10 groups considering the internal adjustment approach: Ctrl - No adjustment; F - Grinding with fine diamond bur (46 μm); F + Pol - Grinding with fine diamond bur followed by polishing with 2 tips (finisher and polisher); FF - Grinding with extrafine diamond bur (30 μm); FF + Pol - Grinding with extrafine diamond bur followed by polishing. In addition, discs (10 mm in diameter, 2.5 mm in thickness) of fiber reinforced epoxy resin were produced. Afterwards, the intaglio surface of the ZR discs were air-abraded with 45 μm alumina particles for 10 s, the LD and resin epoxy discs were etched with hydrofluoric acid (5%/20 s and 10%/60 s, respectively), and the treated discs were primed as recommended. Each ceramic disc was luted onto the epoxy resin disc with resin cement. Then, the samples were tested under a step-stress fatigue test (20 Hz, 10,000 cycles/step, step-size of 100 N starting at 200 N, and proceeding until failure detection). Fractographic, topographic and surface roughness analysis were also performed. The adjustments (grinding with or without polishing) (ZR: 733-880 N; LD: 1040-1106 N) triggered a detrimental effect on the fatigue behavior in both ceramics compared with the absence of treatment (control group; ZR: 973 N; LD: 1406 N). The polishing step had no effect on fatigue findings. Thus, grinding the inner surface of the tested ceramics should be avoided wherever possible to prevent introducing damage and its detrimental effects on the fatigue behavior.
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Affiliation(s)
- Ana Carolina Cadore-Rodrigues
- MSciD and PhD Post-Graduate Program in Oral Sciences (Prosthodontic Units), Faculty of Odontology, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul State, Brazil.
| | - Renan Vaz Machry
- MSciD and PhD Post-Graduate Program in Oral Sciences (Prosthodontic Units), Faculty of Odontology, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul State, Brazil.
| | - Camila Pauleski Zucuni
- MSciD and PhD Post-Graduate Program in Oral Sciences (Prosthodontic Units), Faculty of Odontology, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul State, Brazil.
| | - Gabriel Kalil Rocha Pereira
- MSciD and PhD Post-Graduate Program in Oral Sciences (Prosthodontic Units), Faculty of Odontology, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul State, Brazil.
| | - Luiz Felipe Valandro
- MSciD and PhD Post-Graduate Program in Oral Sciences (Prosthodontic Units), Faculty of Odontology, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul State, Brazil.
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Borges ALS, Tribst JPM, de Lima AL, Dal Piva AMDO, Özcan M. Effect of occlusal anatomy of CAD/CAM feldspathic posterior crowns in the stress concentration and fracture load. Clin Exp Dent Res 2021; 7:1190-1196. [PMID: 34240808 PMCID: PMC8638277 DOI: 10.1002/cre2.454] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 04/21/2021] [Accepted: 05/05/2021] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVES This study evaluated the effect of restoration occlusal design on the maximum fracture load and stress distribution of a feldspathic ceramic crown. MATERIALS AND METHODS Twenty dentin analogues were used to simulate a full-crown preparation. Next, 20 feldspathic crowns were milled according to the occlusal design parameter available in the CAD database (Young or Adult). The crowns were cemented with dual cure resin-cement and loaded until fracture at 1 mm/min crosshead speed. Data were analyzed by using one-way ANOVA and Tukey tests (p < 0.05). The same geometry and experimental setup was modeled and exported to the computer aided engineering software and tensile stress concentration was calculated using the finite element method with 300 N occlusal load simulation. RESULTS The occlusal anatomy significantly influenced the load-to-fracture (p < 0.05). Adult design showed higher mean values (1149 ± 201 N) than Young design (454 ± 77 N). The maximum principal stress criteria showed similar stress pattern for both designs, however, the highest stress concentration was calculated for Young design (91 MPa) in the occlusal surface. CONCLUSIONS An anatomy design with reduced cusp angulation and less evident occlusal sulcus can reduce the stress concentration and increase the fracture load for feldspathic CAD/CAM posterior crowns.
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Affiliation(s)
- Alexandre Luiz Souto Borges
- Department of Dental Materials and ProstheticsSão Paulo State University (UNESP), Institute of Science and TechnologySão José dos CamposBrazil
| | - João Paulo Mendes Tribst
- Department of Dental Materials and ProstheticsSão Paulo State University (UNESP), Institute of Science and TechnologySão José dos CamposBrazil
| | - Aline Lins de Lima
- Department of Dental Materials and ProstheticsSão Paulo State University (UNESP), Institute of Science and TechnologySão José dos CamposBrazil
| | - Amanda Maria de Oliveira Dal Piva
- Department of Dental Materials and ProstheticsSão Paulo State University (UNESP), Institute of Science and TechnologySão José dos CamposBrazil
| | - Mutlu Özcan
- Division of Dental Biomaterials, Center for Dental and Oral Medicine, Clinic for Reconstructive DentistryUniversity of ZurichZürichSwitzerland
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Velho HC, Dapieve KS, Valandro LF, Pereira GKR, Venturini AB. Cyclic fatigue tests on non-anatomic specimens of dental ceramic materials: A scoping review. J Mech Behav Biomed Mater 2021; 126:104985. [PMID: 34861521 DOI: 10.1016/j.jmbbm.2021.104985] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 11/15/2021] [Accepted: 11/18/2021] [Indexed: 11/16/2022]
Abstract
The aim of the present scoping review was to identify and discuss the methods, testing parameters, and characteristics used to induce cyclic fatigue on non-anatomic dental ceramic specimens. In vitro studies written in English which evaluated commercially-available non-anatomic dental ceramic specimens subjected to mechanical cyclic fatigue were selected. The search was performed in the PubMed, Scopus and Web of Science databases. The initial search yielded 1,636 articles, of which 81 were included. Based on the collected data, most of the included studies evaluated dental ceramic specimens cemented to supporting substrate (n= 42; 51.9%); used step-stress (n= 35; 42.2%) accelerated fatigue test, loading frequencies above 10 Hz (n= 31, 35.6%), stainless steel (n = 28, 32.6%) load applicator with spherical shaped tip 40 mm diameter (n= 25, 30.9%); applied only axial loads (n= 77, 95.1%); and considered a wet testing environment (n= 65, 78.3%). The definition of test geometry, method, and testing parameters must be cautiously considered according to the study objective and the scenario that is simulated. Accelerated fatigue tests, load frequencies up to 20 Hz, a 40 mm stainless steel spherical load applicator and a wet testing environment are the major common defined parameters presented in the existing literature. More studies exploring the influence of such factors on fatigue mechanism are necessary.
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Affiliation(s)
- Helder Callegaro Velho
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil.
| | - Kiara Serafini Dapieve
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil.
| | - Luiz Felipe Valandro
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil.
| | - Gabriel Kalil Rocha Pereira
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil.
| | - Andressa Borin Venturini
- MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil.
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Dapieve KS, Pilecco RO, Pivetta JP, Machry RV, Werner A, Kleverlaan CJ, Pereira GKR, Valandro LF. Is the application of a silane-based coupling agent necessary to stabilize the fatigue performance of bonded simplified lithium disilicate restorations? J Mech Behav Biomed Mater 2021; 126:104989. [PMID: 34864398 DOI: 10.1016/j.jmbbm.2021.104989] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 11/16/2021] [Accepted: 11/18/2021] [Indexed: 11/16/2022]
Abstract
This study evaluated the influence of ceramic surface conditioning and storage regimen (baseline vs. aging) on the fatigue performance of simplified lithium disilicate glass-ceramic restorations. A total of 90 ceramic discs (Ø= 10 mm; thickness= 1.0 mm) were allocated into 6 groups (n= 15), considering 2 factors: "ceramic surface treatment" - CA (only silane-based coupling agent, Monobond N), HF (5% hydrofluoric acid etching), or HF+CA (5% HF acid etching plus silane-based coupling agent); and "storage regimen" - baseline (24 hours - 5 days of distilled water at 37 °C), or long-term aging (180 days of distilled water at 37 °C + 25,000 thermal cycles). After intaglio ceramic conditioning, adhesive bonding (Multilink N) was performed onto epoxy resin discs (Ø= 10 mm; thickness= 2.5 mm) and the bonded sets were subjected to step-stress fatigue tests (initial load: 200 N; step-size: 50 N; 10,000 cycles per step; 20 Hz). Fatigue data were analyzed using Kaplan-Meier and Weibull statistical analyses. Fractography and topography analyses were also conducted. The fatigue findings demonstrated that the performance among groups for both baseline and aging conditions maintained a tendency: the CA groups had the worst behavior (baseline: 893 N/143,667 cycles; aging: 639 N/84,179 cycles), while the surface etching with HF (baseline: 1247 N/214,333 cycles; aging: 816.67 N/128,333 cycles) and HF+CA groups (baseline: 1290 N/222,333 cycles; aging: 900 N/145,000 cycles) had no statistically significant difference between them. The aging protocol reduced the performance of all groups. The groups with better fatigue performance (HF and HF+CA) did not have statistical differences regarding structural reliability (Weibull modulus). Most failures were radial cracks from the cementation interface, except for CA aging specimens, with 27% failing from debonding. The HF etching led to noteworthy surface topographical alterations. Micromechanical interlocking resulting from HF acid etching remained prevalent in the fatigue behavior. Thus, the silane-based coupling agent (Monobond N) does not need to be applied after HF etching in terms of fatigue behavior outcomes.
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Affiliation(s)
- Kiara Serafini Dapieve
- MSciD and PhD Post-Graduate Program in Oral Science, Prosthetic Dentistry Unit, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Rafaela Oliveira Pilecco
- MSciD and PhD Post-Graduate Program in Oral Science, Prosthetic Dentistry Unit, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Jordana Pavanelo Pivetta
- MSciD and PhD Post-Graduate Program in Oral Science, Prosthetic Dentistry Unit, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Renan Vaz Machry
- MSciD and PhD Post-Graduate Program in Oral Science, Prosthetic Dentistry Unit, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Arie Werner
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, Noord-Holland, the Netherlands.
| | - Cornelis Johannes Kleverlaan
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, Noord-Holland, the Netherlands.
| | - Gabriel Kalil Rocha Pereira
- MSciD and PhD Post-Graduate Program in Oral Science, Prosthetic Dentistry Unit, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Luiz Felipe Valandro
- MSciD and PhD Post-Graduate Program in Oral Science, Prosthetic Dentistry Unit, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
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