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Yamaguchi S, Li H, Sakai T, Lee C, Kitagawa H, Imazato S. CAD-CAM resin composites: Effective components for further development. Dent Mater 2024; 40:527-530. [PMID: 38228428 DOI: 10.1016/j.dental.2024.01.002] [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: 01/09/2024] [Indexed: 01/18/2024]
Abstract
OBJECTIVE This paper summarizes the effective components of computer-aided design and computer-aided manufacturing (CAD-CAM) resin composites that contribute to achieving greater mechanical properties and further development. METHODS In silico multi-scale analysis, in silico nonlinear dynamic finite element analysis (FEA), and artificial intelligence (AI) were used to explore the effective components of CAD-CAM resin composites. The effects of the filler diameter and silane coupling ratio on the mechanical properties of CAD-CAM resin composites have been clarified through multi-scale analysis. The effects of the filler contents, and filler and monomer compositions have been investigated by AI algorithms. The fracture behavior of CAD-CAM composite crown was analyzed using in silico non-linear dynamic FEA. The longevity of CAD-CAM composite crown was assessed through step-stress accelerating life testing (SSALT). RESULTS As the filler diameter decreases, there is an increase in elastic moduli and compressive strengths at the macroscale. At the nanoscale, a decrease in the filler diameter results in a decrease in the maximum value of the maximum principal strain. When the silane coupling ratio decreases, there is a decrease in the elastic modulus and compressive strength. According to the exhaustive search and feature importance analysis based on the AI algorithm, the combination of certain components was narrowed down to achieve a flexural strength of 269.5 MPa. The in silico non-linear FEA successfully detected the sign of the initial crack of the CAD-CAM composite molar crown. The SSALT revealed that CAD-CAM resin composite molar crowns containing nanofillers with a high fraction of resin matrix demonstrated great longevity. SIGNIFICANCE This paper summarized the effective components of CAD-CAM resin composites for their further development. The integration of in vitro and in silico approaches will expedite the advancement of CAD-CAM resin composites, offering benefits such as time efficiency and reduction of material waste for researchers and manufacturers.
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Affiliation(s)
- Satoshi Yamaguchi
- Department of Dental Biomaterials, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Hefei Li
- Department of Dental Biomaterials, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Takahiko Sakai
- Department of Fixed Prosthodontics and Orofacial Function, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Chunwoo Lee
- Department of Dental Biomaterials, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Haruaki Kitagawa
- Department of Dental Biomaterials, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Satoshi Imazato
- Department of Dental Biomaterials, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan
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Hoshino IAE, Dos Santos PH, Briso ALF, Sundfeld RH, Yamaguchi S, Rocha EP, Anchieta RB. Biomechanical performance of three fiberglass post cementation techniques: Imaging, in vitro, and in silico analysis. J Prosthodont Res 2023; 67:103-111. [PMID: 35264548 DOI: 10.2186/jpr.jpr_d_21_00253] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
PURPOSE The structural integrity of the resin cement layer, the bond strength, and the biomechanical behavior of different fiberglass post cementation techniques were evaluated. METHODS Thirty-three bovine incisors were divided into three groups (n = 11): conventional fiberglass post (CFP), conventional fiberglass post in flared root canals (CFL), and relined fiberglass post (RFP). Six specimens from each group were submitted for high-resolution microcomputed tomography (μCT) to evaluate the integrity and presence/volume of voids at the resin cement layer. Finite element analysis (FEA) of two three-dimensional (3D) models of each group were conducted, one considered ideal (without interface defects) and another containing the conditions identified in the μCT analysis. Push-out bond strength tests were conducted for all specimens. RESULTS The CFL group had the greatest mean values of void (Thirds cervical: 73.67; middle: 95.67; apical: 47.33) and gap concentration (Thirds cervical: 14.67; middle: 15.83; apical: 8.33) compared with CFP and RFP. A significant difference in bond strength was observed between the cervical (1.33 MPa) and middle thirds (1.85 MPa) compared with the apical third (4.85 MPa) of the CFL. A significant difference was observed in the bond strength in the CFL (1.33 MPa) and RFP (3.29 MPa) in the cervical third, which were statistically similar to the bond strength of the CFP. The tensile stress distributions were similar in most structures, localized in the cervical region on the lingual surface. CONCLUSIONS Structural defects in the interface layer might influence the bond strength and biomechanical behavior under the different fiberglass post cementations.
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Affiliation(s)
- Isis Almela Endo Hoshino
- Department of Preventive Dentistry and Restorative Dentistry, São Paulo State University (UNESP), School of Dentistry, Araçatuba, SP, Brazil
| | - Paulo Henrique Dos Santos
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), School of Dentistry, Araçatuba, SP, Brazil
| | - Andre Luiz Fraga Briso
- Department of Preventive Dentistry and Restorative Dentistry, São Paulo State University (UNESP), School of Dentistry, Araçatuba, SP, Brazil
| | - Renato Herman Sundfeld
- Department of Preventive Dentistry and Restorative Dentistry, São Paulo State University (UNESP), School of Dentistry, Araçatuba, SP, Brazil
| | - Satoshi Yamaguchi
- Department of Biomaterials Science, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - Eduardo Passos Rocha
- Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), School of Dentistry, Araçatuba, SP, Brazil
| | - Rodolfo Bruniera Anchieta
- Department of Preventive Dentistry and Restorative Dentistry, São Paulo State University (UNESP), School of Dentistry, Araçatuba, SP, Brazil.,Department of Prosthodontics, Centro Universitario do Norte Paulista- UNIPOS UNORP, São José do Rio Preto, SP, Brazil
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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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Prott LS, Spitznagel FA, Bonfante EA, Malassa MA, Gierthmuehlen PC. Monolithic zirconia crowns: effect of thickness reduction on fatigue behavior and failure load. J Adv Prosthodont 2021; 13:269-280. [PMID: 34777717 PMCID: PMC8558575 DOI: 10.4047/jap.2021.13.5.269] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 08/30/2021] [Accepted: 09/14/2021] [Indexed: 11/23/2022] Open
Abstract
PURPOSE The objective of this study was to evaluate the effect of thickness reduction and fatigue on the failure load of monolithic zirconia crowns. MATERIALS AND METHODS 140 CAD-CAM fabricated crowns (3Y-TZP, inCorisTZI, Dentsply-Sirona) with different ceramic thicknesses (2.0, 1.5, 1.0, 0.8, 0.5 mm, respectively, named G2, G1.5, G1, G0.8, and G0.5) were investigated. Dies of a mandibular first molar were made of composite resin. The zirconia crowns were luted with a resin composite cement (RelyX Unicem 2 Automix, 3M ESPE). Half of the specimens (n = 14 per group) were mouth-motion-fatigued (1.2 million cycles, 1.6 Hz, 200 N/ 5 – 55℃, groups named G2-F, G1.5-F, G1-F, G0.8-F, and G0.5-F). Single-load to failure was performed using a universal testing-machine. Fracture modes were analyzed. Data were statistically analyzed using a Weibull 2-parameter distribution (90% CI) to determine the characteristic strength and Weibull modulus differences among the groups. RESULTS Three crowns (21%) of G0.8 and five crowns (36%) of G0.5 showed cracks after fatigue. Characteristic strength was the highest for G2, followed by G1.5. Intermediate values were observed for G1 and G1-F, followed by significantly lower values for G0.8, G0.8-F, and G0.5, and the lowest for G0.5-F. Weibull modulus was the lowest for G0.8, intermediate for G0.8-F and G0.5, and significantly higher for the remaining groups. Fatigue only affected G0.5-F. CONCLUSION Reduced crown thickness lead to reduced characteristic strength, even under failure loads that exceed physiological chewing forces. Fatigue significantly reduced the failure load of 0.5 mm monolithic 3Y-TZP crowns.
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Affiliation(s)
- Lea Sophia Prott
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University, Düsseldorf, Germany
| | - Frank Akito Spitznagel
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University, Düsseldorf, Germany
| | - Estevam Augusto Bonfante
- Department of Prosthodontics and Periodontology, Bauru School of Dentistry, University of Sao Paulo, Bauru, SP, Brazil
| | | | - Petra Christine Gierthmuehlen
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University, Düsseldorf, Germany
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Lima JMDC, Tribst JPM, Anami LC, de Melo RM, Moura DMD, Souza ROA, Bottino MA. Long-term fracture load of all-ceramic crowns: Effects of veneering ceramic thickness, application techniques, and cooling protocol. J Clin Exp Dent 2020; 12:e1078-e1085. [PMID: 33262875 PMCID: PMC7680567 DOI: 10.4317/jced.57352] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 07/02/2020] [Indexed: 11/14/2022] Open
Abstract
Background To evaluate, in vitro, the effects of the cooling protocol, application technique, and veneering ceramic thickness on the fracture resistance of ceramic crowns with Y-TZP frameworks.
Material and Methods 80 frameworks were made from zirconia by the CAD/CAM technique and divided into 8 groups (n = 10) according to the factors: “application technique” (stratified-L and pressed -P), “thickness” (1 mm and 2 mm), and “cooling protocol” (slow-S and fast-F) of the feldspathic veneering ceramic. After, all crowns were cemented over G10 preparations with resin cement (Panavia F, Kuraray), mechanically cycled (2x106 cycles, 200 N, 3Hz), and subjected to the axial compression resistance test (0.5 mm/min, 10 kN). The data (N) underwent descriptive statistical analysis by 3-way ANOVA and Tukey’s test (5%). Fracture analysis was performed to determine the possible origin of failure.
Results The factors “cooling protocol” (P=0.0058) and “application” technique (P=0.0001) influenced the fracture resistance of the crowns. For pressed veneer technique, the P2S (4608.9±464.5). A presented significantly higher results than that P2F(3621.1±523.0)BCD (Tukey’s test). For the stratified technique, this difference was not observed (P>0.05). The thickness of the veneering ceramic was not significant regardless of the cooling protocol and technique (P>0.05). The predominant failure mode was chipping of the ceramic veneer originating in the subsurface.
Conclusions The pressed technique, used with a slow-cooling protocol, leads to the best outcome for the veneering of all-ceramic crowns. Key words:Zirconia, ceramics, cooling protocol, thickness, application technique.
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Affiliation(s)
| | - João-Paulo-Mendes Tribst
- DDs, MSc, PhD, Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology, São José dos Campos, São Paulo, Brazil
| | - Lilian-Costa Anami
- DDs, MSc, PhD, Departmentof Dentistry, Santo Amaro University, São Paulo, SP, Brazil
| | - Renata-Marques de Melo
- DDs, MSc, PhD, Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology, São José dos Campos, São Paulo, Brazil
| | - Dayanne-Monielle-Duarte Moura
- DDs, MSc, PhD, Department of Dentistry, Division of Prosthodontics, Federal University of Rio Grande do Norte (UFRN), Natal/RN, Brazil
| | - Rodrigo-Othávio-Assunção Souza
- DDs, MSc, PhD, Department of Dentistry, Division of Prosthodontics, Federal University of Rio Grande do Norte (UFRN), Natal/RN, Brazil
| | - Marco-Antonio Bottino
- DDs, MSc, PhD, Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology, São José dos Campos, São Paulo, Brazil
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Dal Piva AMDO, Tribst JPM, Benalcázar Jalkh EB, Anami LC, Bonfante EA, Bottino MA. Minimal tooth preparation for posterior monolithic ceramic crowns: Effect on the mechanical behavior, reliability and translucency. Dent Mater 2020; 37:e140-e150. [PMID: 33246664 DOI: 10.1016/j.dental.2020.11.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 08/10/2020] [Accepted: 11/02/2020] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Despite the increased use of monolithic crowns, their performance has yet to be determined when the minimal tooth preparation (MTP) principle is considered. The goal of this study was to evaluate the effect of MTP on the mechanical behavior, reliability and translucency of posterior monolithic ceramic crowns. METHODS Dentin analogues were machined using two preparation designs (0.5 or 1 mm reduction) to receive first molar crowns in order to evaluate the monolithic crown performance. Next, 126 crowns were divided (21/g) according to the material (High translucent zirconia - YZHT, Zirconia reinforced lithium silicate - ZLS and Hybrid ceramic - HC) and thickness (0.5 or 1 mm). Tensile stress concentration was calculated using the finite element method. The crowns were adhesivelly cemented and step stress fatigued to calculate reliability for missions at 600 and 1000 N. Translucency was analyzed in 10 discs of each material and thickness. RESULTS Higher stress concentration was found in thinner crowns and those with higher elastic modulus. YZHT crowns were suspended when fatigue reached 1500 N load, thus 1-parameter Weibull was used to analyze the data. Reliability was only affected by thickness at 1000 N. ZLS.5 showed lower survival than HC.5, which was similar to the groups that presented 100% survival. YZHT showed the highest strength and data scattering. ZLS1 (22.3 ± 1.4) presented higher translucency than HC1 (19.2 ± 0.6) and YZHT1 (12.0 ± 2.9), whereas ZLS.5 and HC.5 were similar to each other (26.5 ± 2.3, 26.7 ± 2.2) and superior to YZHT.5 (12.7 ± 1.2). SIGNIFICANCE HC.5 combined high reliability and translucency with low stress concentration, yielding better crown performance and tooth preservation.
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Affiliation(s)
- Amanda Maria de Oliveira Dal Piva
- PhD Graduate Program in Restorative Dentistry, São Paulo State University (Unesp), Institute of Science and Technology, Av. Eng. Francisco José Longo, nº 777, Jardim São Dimas, 12245-000 São José dos Campos, SP, Brazil.
| | - João Paulo Mendes Tribst
- PhD Graduate Program in Restorative Dentistry, São Paulo State University (Unesp), Institute of Science and Technology, Av. Eng. Francisco José Longo, nº 777, Jardim São Dimas, 12245-000 São José dos Campos, SP, Brazil.
| | - Ernesto Byron Benalcázar Jalkh
- Department of Prosthodontics and Periodontology, University of São Paulo - Bauru School of Dentistry. Alameda Dr. Octávio Pinheiro Brisolla, 9-75, 17012-901, Bauru, SP, Brazil.
| | - Lilian Costa Anami
- PhD Graduate Program in Restorative Dentistry, São Paulo State University (Unesp), Institute of Science and Technology, Av. Eng. Francisco José Longo, nº 777, Jardim São Dimas, 12245-000 São José dos Campos, SP, Brazil.
| | - Estevam Augusto Bonfante
- Department of Prosthodontics and Periodontology, University of São Paulo - Bauru School of Dentistry. Alameda Dr. Octávio Pinheiro Brisolla, 9-75, 17012-901, Bauru, SP, Brazil.
| | - Marco Antonio Bottino
- PhD Graduate Program in Restorative Dentistry, São Paulo State University (Unesp), Institute of Science and Technology, Av. Eng. Francisco José Longo, nº 777, Jardim São Dimas, 12245-000 São José dos Campos, SP, Brazil.
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Monolithic CAD/CAM laminate veneers: Reliability and failure modes. Dent Mater 2020; 36:724-732. [DOI: 10.1016/j.dental.2020.03.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 02/12/2020] [Accepted: 03/12/2020] [Indexed: 12/20/2022]
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Rayyan MM, Abdallah J, Segaan LG, Bonfante EA, Osman E. Static and Fatigue Loading of Veneered Implant-Supported Fixed Dental Prostheses. J Prosthodont 2020; 29:679-685. [PMID: 32271486 DOI: 10.1111/jopr.13173] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 04/03/2020] [Accepted: 04/03/2020] [Indexed: 12/01/2022] Open
Abstract
PURPOSE This study aimed to compare the load to failure and the probability of survival of porcelain fused to zirconia (PFZ) three-unit, implant-supported, fixed dental prostheses (FDPs) to those of indirect composites veneered to either zirconia (CVZ) or milled fiber-reinforced composite (FRC) frameworks under static and fatigue loading. MATERIALS AND METHODS One-hundred and twenty posterior three-unit FDP (second premolar pontic) frameworks were fabricated via milling from a single Standard Tessellation Language (STL) file. The FDPs were divided into three groups. Each group (n = 40) was subjected to static (n = 20) and fatigue (n = 20) loading tests, as follows: (1) PFZ: zirconia framework layered with porcelain veneer; (2) CVZ: zirconia framework veneered with indirect composite resin; and (3) FRC: FRC framework veneered with indirect composite resin. After porcelain veneering onto sintered zirconia frameworks, or resin composite veneering onto zirconia or FRC frameworks, FDPs were cemented on their abutments using self-adhesive resin cement. After thermal cycling, half of the FDPs were subjected to an accelerated fatigue test. The other half of the FDPs were subjected to single load-to-failure (SLF) testing at a crosshead speed (1 mm/min). Lifetime analysis was conducted to determine the probability of survival, and fractographic analysis was performed. RESULTS Significant differences were observed among the studied groups for SLF with the highest characteristic strength values observed for PFZ (2154 N), followed by 1905.47 N for CVZ and 1679.56 N for FRC. The probability of survival for 100,000 cycles at 500 N was the highest for FRC (98%) and CVZ (100%) and was significantly lower for PFZ (88%). Different fracture patterns were observed in the fractography. CONCLUSIONS In fatigue testing, which simulates masticatory function better than static tests, a higher probability of survival was observed for FRC and CVZ than for PFZ. Framework fractures were not observed only for the FRC group, indicating that chairside repair with the addition of indirect composite could be performed for continued function.
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Affiliation(s)
- Mohammad M Rayyan
- Professor, Department of Oral Rehabilitation Sciences, Faculty of Dentistry, Beirut Arab University, Beirut, Lebanon
| | - Jihad Abdallah
- Clinical Professor, Department of Oral and Surgical Sciences, Faculty of Dentistry, Beirut Arab University, Beirut, Lebanon
| | - Lucette G Segaan
- Professor, Department of Oral Rehabilitation Sciences, Faculty of Dentistry, Beirut Arab University, Beirut, Lebanon
| | - Estevam A Bonfante
- Assistant Professor, Department of Prosthodontics and Periodontology, University of São Paulo - Bauru School of Dentistry, Bauru, SP, Brazil
| | - Essam Osman
- Professor, Department of Oral Rehabilitation Sciences, Faculty of Dentistry, Beirut Arab University, Beirut, Lebanon
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Bergamo ET, Bordin D, Ramalho IS, Lopes AC, Gomes RS, Kaizer M, Witek L, Bonfante EA, Coelho PG, Del Bel Cury AA. Zirconia-reinforced lithium silicate crowns: Effect of thickness on survival and failure mode. Dent Mater 2019; 35:1007-1016. [DOI: 10.1016/j.dental.2019.04.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 02/12/2019] [Accepted: 04/12/2019] [Indexed: 10/26/2022]
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de Andrade GS, Tribst JPM, Dal Piva AMDO, Bottino MA, Borges ALS, Valandro LF, Özcan M. A study on stress distribution to cement layer and root dentin for post and cores made of CAD/CAM materials with different elasticity modulus in the absence of ferrule. J Clin Exp Dent 2019; 11:e1-e8. [PMID: 30697387 PMCID: PMC6343998 DOI: 10.4317/jced.55295] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 12/17/2018] [Indexed: 11/05/2022] Open
Abstract
Background To evaluate the stress distribution in a maxillary central incisor with different post and cores made of six CAD/CAM materials with different elastic modulus in the absence of ferrule using the finite element analysis. Material and Methods A three-dimensional endodontically treated maxillary central incisor restored with an all-ceramic crown was modelled in Rhinoceros (5.0 SR8, McNeel). The geometries were analyzed in ANSYS 17.2 (ANSYS Inc.) considering isotropic, homogeneous, linearly elastic materials with perfectly bonded contacts. The elastic moduli (E) of the post-and-cores defined the groups to be compared: nanoceramic resin (E=12.8GPa); composite resin (E=16GPa); hybrid ceramic (E=34.7GPa); lithium disilicate (E=95GPa); titanium (Ti-Al6-V4) (E=112GPa); and Y-TZP material (E=209.3GPa). The set was constrained in the cortical bone and loaded (45°/100 N) on the incisor palatine face. Stress distribution was analyzed by Maximum Principal Stress criteria for the crown-core cement line, Post-and-core's cement line, Post-and-core system and Dentin. Results The stress distribution at the crown-core cement line (11.4 - 13.2 MPa) was inversely proportional to the increase of the elastic modulus of the post-core approaches, while it was direct proportional on the post-and-core (4.7 - 40 MPa) and cement line (4.1 - 6.2 MPa). Stress distribution on the dentin was similar for all groups (24.7 - 25.3). Conclusions Post-and-core made by CAD/CAM seems to be an efficient treatment alternative, since it is a conservative approach, promotes better aesthetic quality and it allows the control of the cement line thickness. Key words:Endodontically treated teeth, Post-and-core technique, Ceramic crown, Finite element analysis, Biomimetics.
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Affiliation(s)
- Guilherme-Schmidt de Andrade
- DDs, MSc Student in Prosthodontics, Department of Dental Materials and Proshodontics, São Paulo State University (Unesp), Institute of Science and Technology, São José dos Campos / SP, Brazil. Address: Av Engenheiro Francisco José Longo, 777, Jardim São Dimas, São José dos Campos, São Paulo, Brazil
| | - João-Paulo-Mendes Tribst
- DDs, MSc, PhD Student, Department of Dental Materials and Proshodontics, São Paulo State University (Unesp), Institute of Science and Technology, São José dos Campos / SP, Brazil. Address: Av Engenheiro Francisco José Longo, 777, Jardim São Dimas, São José dos Campos, São Paulo, Brazil
| | - Amanda-Maria-de Oliveira Dal Piva
- DDs, MSc, PhD Student, Department of Dental Materials and Proshodontics, São Paulo State University (Unesp), Institute of Science and Technology, São José dos Campos / SP, Brazil. Address: Av Engenheiro Francisco José Longo, 777, Jardim São Dimas, São José dos Campos, São Paulo, Brazil
| | - Marco-Antonio Bottino
- DDs, MSc, PhD, Professor, Department of Dental Materials and Proshodontics, São Paulo State University (Unesp), Institute of Science and Technology, São José dos Campos / SP, Brazil. Address: Av Engenheiro Francisco José Longo, 777, Jardim São Dimas, São José dos Campos, São Paulo, Brazil
| | - Alexandre-Luiz-Souto Borges
- DDs, MSc, PhD, Adjunct Professor, Department of Dental Materials and Proshodontics, São Paulo State University (Unesp), Institute of Science and Technology, São José dos Campos / SP, Brazil. Address: Av Engenheiro Francisco José Longo, 777, Jardim São Dimas, São José dos Campos, São Paulo, Brazil
| | - Luiz-Felipe Valandro
- DDs, MSc, PhD, Professor, Federal University of Santa Maria, Prosthodontic Unit, Faculty of Odontology, Santa Maria, Rio Grande do Sul State, Brazil
| | - Mutlu Özcan
- DDs, MSc, PhD, Professor, University of Zurich, Dental Materials Unit, Center for Dental and Oral Medicine, Clinic for Fixed and Removable Prosthodontics and Dental Materials Science, Zurich, Switzerland
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Heintze SD, Monreal D, Reinhardt M, Eser A, Peschke A, Reinshagen J, Rousson V. Fatigue resistance of all-ceramic fixed partial dentures - Fatigue tests and finite element analysis. Dent Mater 2018; 34:494-507. [PMID: 29395474 DOI: 10.1016/j.dental.2017.12.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 12/11/2017] [Accepted: 12/16/2017] [Indexed: 10/18/2022]
Abstract
OBJECTIVE To estimate the fatigue resistance of a new translucent zirconia material in comparison to lithium disilicate for 3-unit fixed partial dentures (FPDs). METHODS Eighteen 3-unit FPDs (replacement of first upper molar) with a connector size of 4mm×4mm were dry milled with a five-axis milling machine (Zenotec Select, Wieland, Germany) using discs made of a new translucent zirconia material (IPS e.max ZirCAD MT, Ivoclar Vivadent). Another 9 FPDs with a reduced connector size (3mm×4mm) were milled. The zirconia FPDs were sintered at 1500°C. For a comparison, 9 FPDs were made of IPS e.max Press, using the same dimensions. These IPS e.max Press FPDs were ground from a wax disc (Wieland), invested and pressed at 920°C. All FPDs were glazed twice. The FPDs were adhesively luted to PMMA dies with Multilink Automix. Dynamic cyclic loading was carried out on the molar pontic using Dyna-Mess testing machines (Stolberg, Germany) with 2×106 cycles at 2Hz in water (37°C). Two specimens per group and load were subjected to decreasing load levels (at least 4) until the two specimens no longer showed any failures. Another third specimen was subjected to this load to confirm the result. All the specimens were evaluated under a stereo microscope (20× magnification). The number of cycles reached before observing a failure, and their dependence on the load and on the material, were modeled, using a Weibull model. This made it possible to estimate the fatigue resistance as the maximum load for which one would observe less than 1% failure after 2×106 cycles. In addition to the experimental study, Finite Element Modeling (FEM) simulations were conducted to predict the force to failure for IPS e.max ZirCAD MT and IPS e.max Press with a reduced cross-section of the connectors. RESULTS The failure mode of the zirconia FPDs was mostly the fracture of the distal connector, whereas the failure mode of the lithium disilicate FPDs observed to be the fracture of the connectors or multiple cracks of the pontic. The fatigue resistance with 1% fracture probability was estimated to be 488N for the IPS e.max ZirCAD MT FPDs (453N for repeated test), 365N for IPS e.max ZirCAD MT FPDs with reduced connector size and 286N for the e.max Press FPDs. All three IPS e.max ZirCAD groups statistically performed significantly better than IPS e.max Press (p<0.001). On the other hand, no significant difference could be established between the two IPS e.max ZirCAD MT3 groups with a 4mm×4mm connector size (p>0.05). The allowable maximum principal stress (σmax) which did not lead to failure during fatigue testing for IPS e.max ZirCAD MT3 was calculated between 208MPa and 223MPa for FPDs with 4mm×4mm connectors for 2×106 cycles. This value could also be verified for the FPDs of the same material with 3mm×4mm connectors. On the other hand fatigue strength in terms of σmax at 2×106 cycles of IPS e.max Press was calculated to be between 78 and 90MPa. SIGNIFICANCE The fatigue resistance of the translucent zirconia 3-unit FPDs was about 60-70% higher than that of the lithium disilicate 3-unit FPDs, which may justify their use for molar replacements, provided that a minimal connector size of 4mm×4mm is observed. Even with a limited number of specimens (n=9) per group it was possible to statistically differentiate between the tested groups.
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Affiliation(s)
- S D Heintze
- R&D, Ivoclar Vivadent AG, Bendererstrasse 2, FL-9494 Schaan, Liechtenstein.
| | - D Monreal
- R&D, Ivoclar Vivadent AG, Bendererstrasse 2, FL-9494 Schaan, Liechtenstein
| | - M Reinhardt
- R&D, Ivoclar Vivadent AG, Bendererstrasse 2, FL-9494 Schaan, Liechtenstein
| | - A Eser
- R&D, Ivoclar Vivadent AG, Bendererstrasse 2, FL-9494 Schaan, Liechtenstein
| | - A Peschke
- R&D, Ivoclar Vivadent AG, Bendererstrasse 2, FL-9494 Schaan, Liechtenstein
| | | | - V Rousson
- University Hospital Lausanne, Biostatistical Division, Institute for Social and Preventive Medicine, Switzerland
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Soares LM, Soares C, Miranda ME, Basting RT. Influence of Core-Veneer Thickness Ratio on the Fracture Load and Failure Mode of Zirconia Crowns. J Prosthodont 2017; 28:209-215. [DOI: 10.1111/jopr.12601] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/07/2017] [Indexed: 11/30/2022] Open
Affiliation(s)
- Luciana Mara Soares
- Department of Restorative Dentistry; Herman Ostrow School of Dentistry of USC; Los Angeles CA
| | | | - Milton Edson Miranda
- Department of Prosthodontics; São Leopoldo Mandic Institute and Dental Research Center; Campinas São Paulo Brazil
| | - Roberta Tarkany Basting
- Department of Restorative Dentistry; São Leopoldo Mandic Institute and Dental Research Center; Campinas São Paulo Brazil
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Heintze S, Eser A, Monreal D, Rousson V. Using a chewing simulator for fatigue testing of metal ceramic crowns. J Mech Behav Biomed Mater 2017; 65:770-780. [DOI: 10.1016/j.jmbbm.2016.09.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 08/29/2016] [Accepted: 09/01/2016] [Indexed: 11/26/2022]
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Pinto PA, Colas G, Filleter T, De Souza GM. Surface and Mechanical Characterization of Dental Yttria-Stabilized Tetragonal Zirconia Polycrystals (3Y-TZP) After Different Aging Processes. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2016; 22:1179-1188. [PMID: 27780486 DOI: 10.1017/s1431927616011843] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Yttria-stabilized tetragonal zirconia polycrystals (3Y-TZP) is a ceramic material used in indirect dental restorations. However, phase transformation at body temperature may compromise the material's mechanical properties, affecting the clinical performance of the restoration. The effect of mastication on 3Y-TZP aging has not been investigated. 3Y-TZP specimens (IPS E-max ZirCAD and Z5) were aged in three different modes (n=13): no aging (control), hydrothermal aging (HA), or chewing simulation (CS). Mechanical properties and surface topography were analyzed. Analysis of variance showed that neither aging protocol (p=0.692) nor material (p=0.283) or the interaction between them (p=0.216) had a significant effect on flexural strength, values ranged from 928.8 MPa (IPSHA) to 1,080.6 MPa (Z5HA). Nanoindentation analysis showed that material, aging protocol, and the interaction between them had a significant effect (p<0.001) on surface hardness and reduced Young's modulus. The compositional analysis revealed similar yttrium content for all the experimental conditions (aging: p=0.997; material: p=0.248; interaction material×aging: p=0.720). Atomic force microscopy showed an effect of aging protocols on phase transformation, with samples submitted to CS exhibiting features compatible with maximized phase transformation, such as increased volume of the material microstructure at the surface leading to an increase in surface roughness.
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Affiliation(s)
- Palena A Pinto
- 1Faculty of Dentistry,University of Toronto,Edward Street #352E,Toronto,ON,Canada,M5G 1G6
| | - Guillaume Colas
- 2Department of Mechanical and Industrial Engineering,University of Toronto,5 King's College Road #MB115,Toronto,ON,Canada,M5S 3G8
| | - Tobin Filleter
- 2Department of Mechanical and Industrial Engineering,University of Toronto,5 King's College Road #MB115,Toronto,ON,Canada,M5S 3G8
| | - Grace M De Souza
- 1Faculty of Dentistry,University of Toronto,Edward Street #352E,Toronto,ON,Canada,M5G 1G6
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De Souza GM, Zykus A, Ghahnavyeh RR, Lawrence SK, Bahr DF. Effect of accelerated aging on dental zirconia-based materials. J Mech Behav Biomed Mater 2016; 65:256-263. [PMID: 27595931 DOI: 10.1016/j.jmbbm.2016.08.023] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 08/14/2016] [Accepted: 08/17/2016] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To investigate the effect of aging on phase transformation and mechanical properties of yttria-tetragonal zirconia polycrystal (Y-TZP). MATERIALS AND METHODS Fully-sintered Y-TZP slabs, IPS E-max ZirCAD (ZC - Ivoclar) and Z-5 ceramic (Z5 - C5 Medical Werks), were artificially aged in autoclave for: 0, 30, 60 or 90min. Flexural strength (FS), crystalline changes (X-ray diffraction analysis - XRD) and surface topography were analyzed. 0 and 90min-aged samples were evaluated by nanoindentation to measure hardness and modulus, and results were compared using Wilcoxan Mann Whitney rank sum test (p≤0.05). FS results were compared using two-way ANOVA and Tukey HSD (α=0.05). RESULTS Material factor had significant effect (p=0.001) on flexural strength (Z5=966.95MPa; ZC=847.82MPa), but aging did not. Nanoindentation showed incidence of typical load/depth curves combined with some exhibiting features compatible with cracking. When typical curves were considered, aging had no effect on the modulus and hardness, but hardness was dependent on material type. A steady increase in the m phase related to aging time was observed for ZC samples. The maximum incidence of m phase was 6.56% for Z5/60min. SIGNIFICANCE Flexural strength is not affected by surface transformation in dental Y-TZP. Hydrothermal aging has an effect on m content and surface topography of different zirconia brands, but mechanical tests that can precisely characterize surface changes in aged Y-TZP are still missing.
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Affiliation(s)
- Grace M De Souza
- Department of Clinical Sciences, Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, ON, Canada M5G1G6.
| | - Angelica Zykus
- Department of Clinical Sciences, Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, ON, Canada M5G1G6
| | - Reza R Ghahnavyeh
- Department of Clinical Sciences, Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, ON, Canada M5G1G6
| | - Samantha K Lawrence
- School of Materials Engineering, Purdue University, 701 West Stadium Avenue, West Lafayette, IN 47907-2045, USA
| | - David F Bahr
- School of Materials Engineering, Purdue University, 701 West Stadium Avenue, West Lafayette, IN 47907-2045, USA
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Bonfante EA, Suzuki M, Hirata R, Bonfante G, Fardin VP, Coelho PG. Resin composite repair for implant-supported crowns. J Biomed Mater Res B Appl Biomater 2016; 105:1481-1489. [DOI: 10.1002/jbm.b.33683] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 03/29/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Estevam A. Bonfante
- Department of Prosthodontics; University of São Paulo, Bauru College of Dentistry; Bauru SP Brazil
| | - Marcelo Suzuki
- Department of Operative Dentistry and Prosthodontics; Tufts University School of Dental Medicine; Boston Massachusetts
| | - Ronaldo Hirata
- Department of Biomaterials and Biomimetics; New York University College of Dentistry; New York New York 10010
| | - Gerson Bonfante
- Department of Prosthodontics; University of São Paulo, Bauru College of Dentistry; Bauru SP Brazil
| | - Vinicius P. Fardin
- Department of Prosthodontics; University of São Paulo, Bauru College of Dentistry; Bauru SP Brazil
- Department of Biomaterials and Biomimetics; New York University College of Dentistry; New York New York 10010
| | - Paulo G. Coelho
- Department of Biomaterials and Biomimetics; New York University College of Dentistry; New York New York 10010
- Director for Research; Department of Periodontology and Implant Dentistry; New York University College of Dentistry; New York New York
- Affiliated Faculty; Division of Engineering; New York University Abu Dhabi; Abu Dhabi United Arab Emirates
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Turk AG, Ulusoy M, Yuce M, Akin H. Effect of different veneering techniques on the fracture strength of metal and zirconia frameworks. J Adv Prosthodont 2016; 7:454-9. [PMID: 26816575 PMCID: PMC4722149 DOI: 10.4047/jap.2015.7.6.454] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 09/02/2015] [Accepted: 10/20/2015] [Indexed: 11/08/2022] Open
Abstract
PURPOSE To determine whether the fracture strengths and failure types differed between metal and zirconia frameworks veneered with pressable or layering ceramics. MATERIALS AND METHODS A phantom molar tooth was prepared and duplicated in 40 cobalt-chromium abutments. Twenty metal (IPS d.SIGN 15, Ivoclar, Vivadent, Schaan, Liechtenstein) and 20 zirconia (IPS e.max ZirCAD, Ivoclar) frameworks were fabricated on the abutments. Each framework group was randomly divided into 2 subgroups according to the veneering material: pressable and layering ceramics (n=10). Forty molar crowns were fabricated, cemented onto the corresponding abutments and then thermocycled (5-55℃, 10,000 cycles). A load was applied in a universal testing machine until a fracture occurred on the crowns. In addition, failure types were examined using a stereomicroscope. Fracture load data were analyzed using one-way ANOVA and Tukey HSD post-hoc tests at a significance level of 0.05. RESULTS The highest strength value was seen in metal-pressable (MP) group, whereas zirconia-pressable (ZP) group exhibited the lowest one. Moreover, group MP showed significantly higher fracture loads than group ZP (P=.015) and zirconia-layering (ZL) (P=.038) group. No significant difference in fracture strength was detected between groups MP and ML, and groups ZP and ZL (P>.05). Predominant fracture types were cohesive for metal groups and adhesive for zirconia groups. CONCLUSION Fracture strength of a restoration with a metal or a zirconia framework was independent of the veneering techniques. However, the pressing technique over metal frameworks resisted significantly higher fracture loads than zirconia frameworks.
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Affiliation(s)
- Ayse Gozde Turk
- Department of Prosthodontics, Faculty of Dentistry, University of Ege, Izmir, Turkey
| | - Mubin Ulusoy
- Department of Prosthodontics, Faculty of Dentistry, University of Ege, Izmir, Turkey
| | | | - Hakan Akin
- Department of Prosthodontics, Faculty of Dentistry, Cumhuriyet University, Sivas, Turkey
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18
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Anami LC, Lima JMC, Valandro LF, Kleverlaan CJ, Feilzer AJ, Bottino MA. Fatigue Resistance of Y-TZP/Porcelain Crowns is Not Influenced by the Conditioning of the Intaglio Surface. Oper Dent 2015; 41:E1-12. [PMID: 26266655 DOI: 10.2341/14-166-l] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVES The objective of this study was to investigate the effects of treatments of the intaglio surface of Y-TZP frameworks and luting agents on the fatigue resistance of all-ceramic crowns. METHODS A research design was chosen that attempted to reduce the likelihood of Hertzian cracking and to increase the probability of fracture initiation at the intaglio surface of the framework. Ninety identical preparations were machined in a dentin-like epoxy composite. Each preparation was restored with a Y-TZP framework made by a CAD/CAM system and veneered using feldspathic ceramic. Prior to cementation the intaglio surface of the ceramic was treated using one of four treatments: 1) cleaning with isopropyl alcohol; 2) application of an overglaze; 3) sandblasting with 125 μm aluminum oxide powder; and 4) sandblasting with 30 μm silica powder (CJ). One of three luting cements were used: 1) zinc phosphate; 2) glass ionomer; and 3) adhesive resin cement (PN). All three cements were tested against frameworks that were alcohol cleaned. Only the PN cements were tested against frameworks that had been sandblasted or glazed. Altogether, six groups of 15 specimens each were tested. Fatigue resistance was evaluated using stepwise loads at 1.4 Hz until failure: 5000 cycles at maximum load of 200 N, followed by 10,000 cycles at maximum loads of 800, 1000, 1200, and 1400 N. The cement thickness and failure modes were analyzed using a stereomicroscope and scanning electron microscopy. The results were analyzed using the Kaplan-Meier and Mantel-Cox log rank tests (5%), a one-way analysis of variance, Tukey multiple comparison test, and Weibull nonparametric test. RESULTS The predominant failure mode was chipping of the veneer. The crowns cemented with the adhesive resin cement exhibited chipping failure at higher mean loads than did crowns cemented with cements that usually do not bond strongly with dentin. When the adhesive cement was used, glazing and sandblasting intaglio framework surface treatments exhibited lower mean loads at chipping than did crowns whose intaglio surface was only cleaned with alcohol. Weibull analysis indicated that all specimens had a high ratio of late-to-early failures. CONCLUSIONS The fatigue experiment produced a pattern of failures that is very similar to that observed in clinical trials of Y-TZP crowns that are veneered with feldspathic porcelain. Crowns cemented with an adhesive resin cement exhibited chipping at a significantly higher mean load than those cemented with luting cements that do not usually form strong bonds with dentin. When cemented with adhesive resin cement, glazing or sandblasting the intaglio surface of the framework significantly reduced the mean fatigue loads at which chipping of veneers occurred, as compared to crowns whose intaglio surface had only been cleaned with alcohol. For this cement glazing or sandblasting the intaglio surface of the crown is not recommended.
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Bonfante EA, Suzuki M, Lorenzoni FC, Sena LA, Hirata R, Bonfante G, Coelho PG. Probability of survival of implant-supported metal ceramic and CAD/CAM resin nanoceramic crowns. Dent Mater 2015; 31:e168-77. [DOI: 10.1016/j.dental.2015.05.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Revised: 03/28/2015] [Accepted: 05/15/2015] [Indexed: 01/22/2023]
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20
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Wendler M, Belli R, Petschelt A, Lohbauer U. Characterization of residual stresses in zirconia veneered bilayers assessed via sharp and blunt indentation. Dent Mater 2015; 31:948-57. [DOI: 10.1016/j.dental.2015.05.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 05/06/2015] [Accepted: 05/07/2015] [Indexed: 11/24/2022]
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Delben JA, Barão VA, Ferreira MB, da Silva NR, Thompson VP, Assunção WG. Influence of abutment-to-fixture design on reliability and failure mode of all-ceramic crown systems. Dent Mater 2014; 30:408-16. [DOI: 10.1016/j.dental.2014.01.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 01/07/2014] [Accepted: 01/14/2014] [Indexed: 11/16/2022]
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Abstract
Zirconium dioxide as core ceramic material for dental crowns and bridges, possess high strength, chemical stability and superior aesthetics after veneering. Veneering ceramic is considered to be the weakest part of all-ceramic restorations. The adhesion between the core and veneering porcelain is based on the manner in which the connection occurs in metal-ceramic structures. Standard procedures for connecting zirconia to hard dental tissues and veneering materials do not achieve the required strength of bonding.
The aim of the paper is to investigate different surface treatments of the zirconium dioxide ceramic core and find the best, for achieving highest adhesive bonding values to veneering porcelain. The study was primarily designed to investigate the bonding strength of the veneering porcelain to zirconia with in vitro Macro shear bond strength test. The specimens with different surface treatment of the zirconia were divided in five groups of twelve according to the treatment of zirconium surface and results showed highest bonding values for specimens treated with Rocatec system.
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Stoner BR, Griggs JA, Neidigh J, Piascik JR. Evidence of yttrium silicate inclusions in YSZ-porcelain veneers. J Biomed Mater Res B Appl Biomater 2013; 102:441-6. [PMID: 24106151 DOI: 10.1002/jbm.b.33021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 07/29/2013] [Accepted: 08/01/2013] [Indexed: 11/07/2022]
Abstract
This report introduces the discovery of crystalline defects that can form in the porcelain veneering layer when in contact with yttria-stabilized zirconia (YSZ). The focus was on dental prostheses and understanding the defects that form in the YSZ/porcelain system; however the data reported herein may have broader implications toward the use and stability of YSZ-based ceramics in general. Specimens were cut from fully sintered YSZ plates and veneering porcelain was applied (<1 mm thick) to one surface and fired under manufacturer's recommended protocol. Scanning electron microscopy (SEM) with integrated electron dispersive X-ray (EDAX) was used for microstructural and elemental analysis. EDAX, for chemical analysis and transmission electron diffraction (TED) for structural analysis were both performed in the transmission electron microscope (TEM). Additionally, in order to spatially resolve Y-rich precipitates, micro-CT scans were conducted at varying depths within the porcelain veneer. Local EDAX (SEM) was performed in the regions of visible inclusions and showed significant increases in yttrium concentration. TEM specimens also showed apparent inclusions in the porcelain and selected area electron diffraction was performed on these regions and found the inclusions to be crystalline and identified as either yttrium-silicate (Y2 SiO5 ) or yttrium-disilicate (Y2 Si2 O7 ). Micro-CT data showed that yttrium-silicate precipitates were distributed throughout the thickness of the porcelain veneer. Future studies are needed to determine whether many of the premature failures associated with this materials system may be the result of crystalline flaws that form as a result of high temperature yttrium diffusion near the surfaces of YSZ.
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Affiliation(s)
- Brian R Stoner
- Center for Materials and Electronic Technologies, RTI International, RTP, North Carolina
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Lima JM, Souza ACO, Anami LC, Bottino MA, Melo RM, Souza RO. Effects of thickness, processing technique, and cooling rate protocol on the flexural strength of a bilayer ceramic system. Dent Mater 2013; 29:1063-72. [DOI: 10.1016/j.dental.2013.07.019] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Revised: 04/26/2013] [Accepted: 07/24/2013] [Indexed: 11/28/2022]
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Belli R, Petschelt A, Lohbauer U. Thermal-induced residual stresses affect the fractographic patterns of zirconia-veneer dental prostheses. J Mech Behav Biomed Mater 2013; 21:167-77. [DOI: 10.1016/j.jmbbm.2012.10.022] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 10/10/2012] [Accepted: 10/21/2012] [Indexed: 10/27/2022]
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26
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Monaco C, Tucci A, Esposito L, Scotti R. Microstructural changes produced by abrading Y-TZP in presintered and sintered conditions. J Dent 2013; 41:121-6. [DOI: 10.1016/j.jdent.2012.06.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2011] [Revised: 06/29/2012] [Accepted: 06/30/2012] [Indexed: 10/28/2022] Open
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Sasse M, Eschbach S, Kern M. Randomized clinical trial on single retainer all-ceramic resin-bonded fixed partial dentures: Influence of the bonding system after up to 55 months. J Dent 2012; 40:783-6. [PMID: 22659339 DOI: 10.1016/j.jdent.2012.05.009] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Revised: 05/21/2012] [Accepted: 05/22/2012] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES This study evaluated the clinical outcome of all-ceramic resin-bonded fixed partial dentures (RBFPDs) with a cantilevered single-retainer design. METHODS Thirty anterior zirconia ceramic RBFPDs were inserted using either a phosphate monomer containing resin (Panavia 21 TC; N=16) or an adhesive bonding system with a phosphoric acid acrylate primer (Multilink-Automix with Metal/Zirconia primer; N=14). RESULTS During a mean observation time of 41.7 months one debonding occurred in each group. Both RBFPDs could be rebonded successfully resulting in a three-year survival rate of 100%. CONCLUSION Independent of the bonding system cantilevered zirconia ceramic RBFPDs showed promising results during the first three years. CLINICAL SIGNIFICANCE Single-retainer zirconia ceramic RBFPD present an alternative treatment option offering good aesthetics, a minimal invasive preparation, a high biocompatibility and can even be used to treat juvenile patients who do not yet come into consideration for implant placement. No significant influence of the bonding system used was detected so far.
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Affiliation(s)
- Martin Sasse
- Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Christian-Albrechts University, Arnold-Heller Strasse 16, Kiel, Germany.
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Aboushelib MN, Elmahy WA, Ghazy MH. Internal adaptation, marginal accuracy and microleakage of a pressable versus a machinable ceramic laminate veneers. J Dent 2012; 40:670-7. [PMID: 22542500 DOI: 10.1016/j.jdent.2012.04.019] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 04/19/2012] [Accepted: 04/20/2012] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVES The aim of this study was to evaluate the internal adaptation and marginal properties of ceramic laminate veneers fabricated using pressable and machinable CAD/CAM techniques. MATERIALS AND METHODS 40 ceramic laminate veneers were fabricated by either milling ceramic blocks using a CAD/CAM system (group 1 n=20) or press-on veneering using lost wax technique (group 2 n=20). The veneers were acid etched using hydrofluoric acid, silanated, and cemented on their corresponding prepared teeth. All specimens were stored under water (37 °C) for 60 days, then received thermocycling (15,000 cycles between 5 and 55 °C and dwell time of 90 s) followed by cyclic loading (100,000 cycles between 50 and 100 N) before immersion in basic fuchsine dye for 24 h. Half of the specimens in each group were sectioned in labio-lingual direction and the rest were horizontally sectioned using precision cutting machine (n=10). Dye penetration, internal cement film thickness, and vertical and horizontal marginal gaps at the incisal and cervical regions were measured (α=0.05). RESULTS Pressable ceramic veneers demonstrated significantly lower (F=8.916, P<0.005) vertical and horizontal marginal gaps at the cervical and incisal margins and lower cement film thickness (F=50.921, P<0.001) compared to machinable ceramic veneers. The inferior marginal properties of machinable ceramic veneers were associated with significantly higher microleakage values. CONCLUSIONS Pressable ceramic laminate veneers produced higher marginal adaptation, homogenous and thinner cement film thickness, and improved resistance to microleakage compared to machinable ceramic veneers. CLINICAL SIGNIFICANCE The manufacturing process influences internal and marginal fit of ceramic veneers. Therefore, dentist and laboratory technicians should choose a manufacturing process with careful consideration.
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Mosharraf R, Rismanchian M, Savabi O, Ashtiani AH. Influence of surface modification techniques on shear bond strength between different zirconia cores and veneering ceramics. J Adv Prosthodont 2011; 3:221-8. [PMID: 22259706 PMCID: PMC3259448 DOI: 10.4047/jap.2011.3.4.221] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Revised: 11/18/2011] [Accepted: 11/25/2011] [Indexed: 11/08/2022] Open
Abstract
PURPOSE Veneering porcelain might be delaminated from underlying zirconia-based ceramics. The aim of this study was the evaluation of the effect of different surface treatments and type of zirconia (white or colored) on shear bond strength (SBS) of zirconia core and its veneering porcelain. MATERIALS AND METHODS Eighty zirconia disks (40 white and 40 colored; 10 mm in diameter and 4 mm thick) were treated with three different mechanical surface conditioning methods (Sandblasting with 110 µm Al2O3 particle, grinding, sandblasting and liner application). One group had received no treatment. These disks were veneered with 3 mm thick and 5 mm diameter Cercon Ceram Kiss porcelain and SBS test was conducted (cross-head speed = 1 mm/min). Two and one way ANOVA, Tukey's HSD Past hoc, and T-test were selected to analyzed the data (α=0.05). RESULTS In this study, the factor of different types of zirconia ceramics (P=.462) had no significant effect on SBS, but the factors of different surface modification techniques (P=.005) and interaction effect (P=.018) had a significant effect on SBS. Within colored zirconia group, there were no significant differences in mean SBS among the four surface treatment subgroups (P=0.183). Within white zirconia group, "Ground group" exhibited a significantly lower SBS value than "as milled" or control (P=0.001) and liner (P=.05) groups. CONCLUSION Type of zirconia did not have any effect on bond strength between zirconia core and veneer ceramic. Surface treatment had different effects on the SBS of the different zirconia types and grinding dramatically decreased the SBS of white zirconia-porcelain.
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Affiliation(s)
- Ramin Mosharraf
- Department of Prosthodontics and Torabinejad Dental Research Center, School of Dentistry. Isfahan University of Medical Sciences, Isfahan, Iran
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Baldassarri M, Zhang Y, Thompson VP, Rekow ED, Stappert CFJ. Reliability and failure modes of implant-supported zirconium-oxide fixed dental prostheses related to veneering techniques. J Dent 2011; 39:489-98. [PMID: 21557985 DOI: 10.1016/j.jdent.2011.04.006] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Revised: 04/17/2011] [Accepted: 04/19/2011] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVES To compare fatigue failure modes and reliability of hand-veneered and over-pressed implant-supported three-unit zirconium-oxide fixed-dental-prostheses(FDPs). METHODS Sixty-four custom-made zirconium-oxide abutments (n=32/group) and thirty-two zirconium-oxide FDP-frameworks were CAD/CAM manufactured. Frameworks were veneered with hand-built up or over-pressed porcelain (n=16/group). Step-stress-accelerated-life-testing (SSALT) was performed in water applying a distributed contact load at the buccal cusp-pontic-area. Post failure examinations were carried out using optical (polarized-reflected-light) and scanning electron microscopy (SEM) to visualize crack propagation and failure modes. Reliability was compared using cumulative-damage step-stress analysis (Alta-7-Pro, Reliasoft). RESULTS Crack propagation was observed in the veneering porcelain during fatigue. The majority of zirconium-oxide FDPs demonstrated porcelain chipping as the dominant failure mode. Nevertheless, fracture of the zirconium-oxide frameworks was also observed. Over-pressed FDPs failed earlier at a mean failure load of 696 ± 149N relative to hand-veneered at 882 ± 61N (profile I). Weibull-stress-number of cycles-unreliability-curves were generated. The reliability (2-sided at 90% confidence bounds) for a 400N load at 100K cycles indicated values of 0.84 (0.98-0.24) for the hand-veneered FDPs and 0.50 (0.82-0.09) for their over-pressed counterparts. CONCLUSIONS Both zirconium-oxide FDP systems were resistant under accelerated-life-time-testing. Over-pressed specimens were more susceptible to fatigue loading with earlier veneer chipping.
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Affiliation(s)
- Marta Baldassarri
- Department of Periodontology and Implant Dentistry, Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York 10010, USA
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Heintze SD, Albrecht T, Cavalleri A, Steiner M. A new method to test the fracture probability of all-ceramic crowns with a dual-axis chewing simulator. Dent Mater 2010; 27:e10-9. [PMID: 20932564 DOI: 10.1016/j.dental.2010.09.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2009] [Revised: 06/01/2010] [Accepted: 09/06/2010] [Indexed: 10/19/2022]
Abstract
OBJECTIVES The purpose of this study was to validate a new laboratory method to test all-ceramic systems with regard to the proportion of failures. METHODS Sixteen standardized mandibular molar crowns consisting of two different materials (IPS Empress, IPS e.max Press) were adhesively luted on CAD/CAM milled PMMA abutments (first lower molar, circular chamfer). All crowns were loaded applying an eccentric force in a Willytec chewing simulator (steel stylus, Ø 2.4 mm, 2 mm lateral movement from fossa to cuspal tip) with stepwise increase of the load (3, 5, 9 kg, 100,000 cycles each, 0.8 Hz) and simultaneous thermocycling (5°C/55°C×417 per phase). Another four crowns of each material were subjected to force measurements with a 3D force sensor during dynamic loading of each loading phase using two different lateral movements (from fossa to cusp and vice versa). RESULTS The cumulative forces for the three directions in space were much higher compared to the static load of the chewing simulator (maximal force at 3 kg 60 N, 5 kg 160 N, 9 kg 240 N). There was no statistically significant difference in the mean or maximal force between the two materials or two different lateral movements. During dynamic loading, no fractures occurred in the molar crowns made of IPS e.max Press, whereas 50% of the IPS Empress crowns showed failures (75% fractures and 25% chippings) (log-rank test p=0.002). Most of the Empress crowns fractured during the third loading phase (9 kg). CONCLUSIONS The forces that the dead weights exerted during dynamic loading were 2-3 times higher than those during static loading. None of the lithium disilicate ceramic molar crowns fractured, whereas half of the leucite reinforced molar crowns failed during dynamic loading.
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Affiliation(s)
- S D Heintze
- R&D, Preclinical Research, Ivoclar Vivadent AG, Bendererstrasse 2, FL-9494 Schaan, Liechtenstein.
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