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Heidari N, Amawi R, Seweryniak P, Bakitian F, Vult von Steyern P. Fracture Resistance and Fracture Behaviour of Monolithic Multi-Layered Translucent Zirconia Fixed Dental Prostheses with Different Placing Strategies of Connector: An in vitro Study. Clin Cosmet Investig Dent 2022; 14:61-69. [PMID: 35345450 PMCID: PMC8957397 DOI: 10.2147/ccide.s344941] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 02/03/2022] [Indexed: 11/23/2022] Open
Abstract
Purpose To evaluate the effect of different placing strategies performed in the connector area on fracture resistance and fracture behaviour of monolithic multi-layered translucent zirconia fixed dental prostheses (FDPs). Materials and Methods Thirty 3-unit monolithic FDPs were produced and divided into three groups (n = 10) based on the different strategies for placing the connector area of FDPs in multi-layered zirconia blank with varying contents of yttria ranging from 4 to 5 mol%. The groups were as follows: FDPs with connectors placed in dentin layer with 4 mol% yttria content, FDPs with connectors placed in gradient layer, and FDPs with connectors placed in translucent layer with 5 mol% yttria content. A final group (n = 10) of conventional monolithic zirconia with a monolayer of yttria content (4 mol%) has been used as a control group. The specimens were artificially aged using thermocycling and pre-loading procedures and subsequently loaded to fracture using a universal testing machine. Fracture loads and fracture behaviour were analyzed using one-way ANOVA and Fisher’s exact tests and statistically evaluated (p ≤ 0.05). Results There were no significant differences in fracture loads among the groups based on the placing strategies of the connector area of the FDPs in the multi-layered translucent zirconia blank (p > 0.05). There was no significant difference in fracture loads between monolithic multi-layered translucent zirconia and conventional monolithic translucent zirconia materials (p > 0.05). Fracture behaviour of FDPs with connector area placed in translucent layer differed significantly compared to FDPs with connector area placed in dentin layer and FDPs in control group (p = 0.004). Conclusion The placing strategies of the connector used in the computer aided design and manufacturing procedures do not considerably affect fracture resistance of monolithic FDPs made of multi-layered translucent zirconia. Monolithic FDPs made of multi-layered translucent zirconia show comparable strength to FDPs made of conventional translucent zirconia, but with different fracture behaviour.
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Affiliation(s)
- Nada Heidari
- Department of Materials Science and Technology, Malmö University, Malmö, Sweden
| | - Rasha Amawi
- Department of Materials Science and Technology, Malmö University, Malmö, Sweden
| | | | - Fahad Bakitian
- Department of Restorative Dentistry, Umm Al-Qura University, Makkah, Saudi Arabia
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Müller N, Al-Haj Husain N, Chen L, Özcan M. Adhesion of Different Resin Cements to Zirconia: Effect of Incremental versus Bulk Build Up, Use of Mould and Ageing. MATERIALS 2022; 15:ma15062186. [PMID: 35329640 PMCID: PMC8950668 DOI: 10.3390/ma15062186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/11/2022] [Accepted: 03/13/2022] [Indexed: 11/21/2022]
Abstract
Bonding to zirconia presents a great challenge, as the clinical guidelines for predictable adhesion are not sufficiently validated. The aim of this study was to assess the influence of various bonding methodologies of various resin cements on zirconia, using different aging protocols. Manufactured zirconia specimens (N = 300 and n = 20 per group) were randomly assigned to three luting protocols: 1—in mould incremental build up; 2—in mould incremental build up with mould removal; 3—in mould non-incremental bulk build up. Five dual, photo- and chemical-cure resin cements were used, namely, Variolink Esthetic (Ivoclar), Tetric (Ivoclar), Panavia (Kuraray), TheraCem (Bisco), and RelyX UniCem (3M ESPE), and were applied on primed zirconia using photopolymerization protocols. Thereafter, the specimens were subjected to the following three ageing methods: 1—dry; 2—thermocycling (×5000; 5−55 °C); 3—3−6 months of water storage. Using a universal testing machine, the specimens were loaded under shear, at 1 mm/min crosshead speed. An analysis of the data was performed using three-way ANOVA and the Bonferroni method. The moulding type, ageing and luting cement significantly affected the results (p < 0.05). Among all the protocols under dry conditions, TheraCem (16 ± 3; 11 ± 1; 16 ± 3) showed the best bond strength, while, after thermocycling, TheraCem (7 ± 2) and Tetric (7 ± 2) performed the best with Protocol 1. In Protocol 2, RelyX (7 ± 3) presented the highest result, followed by TheraCem (5 ± 3) and Tetric (5 ± 1) (p < 0.05). Using Protocol 3, RelyX (10 ± 6) showed the highest result, followed by TheraCem (7 ± 2) and Panavia21 (7 ± 2) (p < 0.05). Six months after water storage, TheraCem presented the highest result (10 ± 2) in Protocol 1, while, in Protocols 2 and 3, Tetric (10 ± 2; 15 ± 5) presented the highest result, followed by TheraCem (6 ± 2; 8 ± 3). Adhesion tests using the incremental or bulk method, using moulds, showed the highest results, but removing the mould, and the subsequent ageing, caused a decrease in the adhesion of the resin cements tested on zirconia, probably due to water absorption, with the exclusion of Tetric.
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Affiliation(s)
- Nicolas Müller
- Center of Dental Medicine, Division of Dental Biomaterials, Clinic for Reconstructive Dentistry, University of Zurich, Plattenstrasse 22, 8032 Zurich, Switzerland; (N.M.); (N.A.-H.H.)
| | - Nadin Al-Haj Husain
- Center of Dental Medicine, Division of Dental Biomaterials, Clinic for Reconstructive Dentistry, University of Zurich, Plattenstrasse 22, 8032 Zurich, Switzerland; (N.M.); (N.A.-H.H.)
- Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, 3010 Bern, Switzerland
| | | | - Mutlu Özcan
- Center of Dental Medicine, Division of Dental Biomaterials, Clinic for Reconstructive Dentistry, University of Zurich, Plattenstrasse 22, 8032 Zurich, Switzerland; (N.M.); (N.A.-H.H.)
- Correspondence: ; Tel.: +41-44-6343251; Fax: +41-44-6344305
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Alqutaibi AY, Ghulam O, Krsoum M, Binmahmoud S, Taher H, Elmalky W, Zafar MS. Revolution of Current Dental Zirconia: A Comprehensive Review. Molecules 2022; 27:1699. [PMID: 35268800 PMCID: PMC8911694 DOI: 10.3390/molecules27051699] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 02/16/2022] [Accepted: 03/02/2022] [Indexed: 01/27/2023] Open
Abstract
The aim of this article is to comprehensively review the revolution of dental zirconia (Zir), including its types, properties, applications, and cementation procedures. A comprehensive search of PubMed and Embase was conducted. The search was limited to manuscripts published in English. The final search was conducted in October 2021. Newly developed monolithic Zir ceramics have substantially enhanced esthetics and translucency. However, this material must be further studied in vitro and in vivo to determine its long-term ability to maintain its exceptional properties. According to the literature, monolithic translucent Zir has had promising results and a high survival rate. Thus, the utilization of this material is indicated when strength and esthetics are needed. Both the materials and methods used for cementation of monolithic Zir have significantly improved, encouraging dentists to use this material, especially when a conservative approach is required. Zir restorations showed promising outcomes, particularly for monolithic Zir crowns supported with implant and fixed dental prostheses.
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Affiliation(s)
- Ahmed Yaseen Alqutaibi
- Department of Prosthodontics, College of Dentistry, Taibah University, Al Madinah 41311, Saudi Arabia;
- Department of Prosthodontics, College of Dentistry, Ibb University, Ibb 70270, Yemen
| | - Omar Ghulam
- Dental Department, Prince Mohammad bin Abdulaziz Hospital (Ministry of National Guard-Health Affairs), Madinah 42324, Saudi Arabia; (O.G.); (M.K.); (H.T.)
| | - Majid Krsoum
- Dental Department, Prince Mohammad bin Abdulaziz Hospital (Ministry of National Guard-Health Affairs), Madinah 42324, Saudi Arabia; (O.G.); (M.K.); (H.T.)
| | - Suhail Binmahmoud
- Dental Department, Prince Sultan Armed Forces Hospital, Madinah 42375, Saudi Arabia;
| | - Hasan Taher
- Dental Department, Prince Mohammad bin Abdulaziz Hospital (Ministry of National Guard-Health Affairs), Madinah 42324, Saudi Arabia; (O.G.); (M.K.); (H.T.)
| | - Wael Elmalky
- Department of Restorative Dentistry, College of Dentistry, Taibah University, Al Madinah 41311, Saudi Arabia;
| | - Muhammad Sohail Zafar
- Department of Restorative Dentistry, College of Dentistry, Taibah University, Al Madinah 41311, Saudi Arabia;
- Department of Dental Materials, Islamic International Dental College, Riphah International University, Islamabad 44000, Pakistan
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Alammar A, Blatz MB. The resin bond to high‐translucent zirconia—A systematic review. J ESTHET RESTOR DENT 2022; 34:117-135. [DOI: 10.1111/jerd.12876] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/20/2021] [Accepted: 12/31/2021] [Indexed: 02/01/2023]
Affiliation(s)
- Amirah Alammar
- Sijam Medical Center, Private Practice Riyadh Saudi Arabia
| | - Markus B. Blatz
- School of Dental Medicine, Department of Preventive and Restorative Sciences University of Pennsylvania Philadelphia Pennsylvania USA
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Hinz S, Bensel T, Bömicke W, Henningsen A, Rudolph J, Boeckler AF. Impact of the Veneering Technique and Framework Material on the Failure Loads of All-Ceramic Computer-Aided Design/Computer-Aided Manufacturing Fixed Partial Dentures. MATERIALS 2022; 15:ma15030756. [PMID: 35160701 PMCID: PMC8836578 DOI: 10.3390/ma15030756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 01/08/2022] [Accepted: 01/15/2022] [Indexed: 02/04/2023]
Abstract
Objectives: Zirconia (Y-TZP) ceramics are considered as posterior fixed partial denture (FPD) materials; however, their applications are limited due to chipping. The use of monolithic lithium disilicate (LiDi) glass ceramics in posterior FPDs can be advantageous. This in vitro study aims to compare the loads until failure of posterior Y-TZP-FPDs and LiDi-FPDs before and after aging.
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Affiliation(s)
- Sebastian Hinz
- Department of Prosthodontics, Martin-Luther-University Halle-Wittenberg, Magdeburgerstraße 16, 06112 Halle, Germany; (J.R.); (A.F.B.)
- Correspondence: (S.H.); (T.B.)
| | - Tobias Bensel
- Department of Prosthodontics, Martin-Luther-University Halle-Wittenberg, Magdeburgerstraße 16, 06112 Halle, Germany; (J.R.); (A.F.B.)
- Correspondence: (S.H.); (T.B.)
| | - Wolfgang Bömicke
- Department of Prosthetic Dentistry, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany;
| | - Anders Henningsen
- Department of Oral and Maxillofacial Surgery, University Hospital Hamburg-Eppendorf, 20246 Hamburg, Germany;
| | - Judith Rudolph
- Department of Prosthodontics, Martin-Luther-University Halle-Wittenberg, Magdeburgerstraße 16, 06112 Halle, Germany; (J.R.); (A.F.B.)
| | - Arne F. Boeckler
- Department of Prosthodontics, Martin-Luther-University Halle-Wittenberg, Magdeburgerstraße 16, 06112 Halle, Germany; (J.R.); (A.F.B.)
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Juntavee N, Juntavee A, Phattharasophachai T. Biaxial Flexural Strength of Different Monolithic Zirconia upon Post-Sintering Processes. Eur J Dent 2022; 16:585-593. [PMID: 35016234 PMCID: PMC9507572 DOI: 10.1055/s-0041-1735937] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
OBJECTIVE Different post-sintering processes are expected to be a reason for alteration in the strength of zirconia. This study evaluated the effect of post-sintering processes on the flexural strength of different types of monolithic zirconia. MATERIALS AND METHODS A total of 120 classical- (Cz) and high-translucent (Hz) monolithic zirconia discs (1.2 mm thickness and 14 mm in Ø) were prepared, sintered, and randomly divided into four groups to be surface-treated with (1) as-glazed (AG); (2) finished and polished (FP); (3) finished, polished, and overglazed (FPOG); and (4) finished, polished, and heat-treated (FPHT) technique (n = 15). Biaxial flexural strength (σ) was determined on a piston-on-three ball in a universal testing machine at a speed of 0.5 mm/min. STATISTICAL ANALYSIS Analysis of variance, and post hoc Bonferroni multiple comparisons were determined for significant differences (α = 0.05). Weibull analysis was applied for survival probability, Weibull modulus (m), and characteristic strength (σ0). The microstructures were examined with a scanning electron microscope and X-ray diffraction. RESULTS The mean ± standard deviation value of σ (MPa), m, and σ0 were 1,626.43 ± 184.38, 9.51, and 1,709.79 for CzAG; 1,734.98 ± 136.15, 12.83, and 1,799.17 for CzFP; 1,636.92 ± 130.11, 14.66, and 1,697.63 for CzFPOG; and 1,590.78 ± 161.74, 10.13, and 1,663.82 for CzFPHT; 643.30 ± 118.59, 5.59, and 695.55 for HzAG; 671.52 ± 96.77, 3.28, and 782.61 for HzFP; 556.33 ± 122.85, 4.76, and 607.01 for HzFPOG; and 598.36 ± 57.96, 11.22, and 624.89 for HzFPHT. The σ was significantly affected by the post-sintering process and type of zirconia (p < 0.05), but not by their interactions (p > 0.05). The Cz indicated a significantly higher σ than Hz. The FP process significantly enhanced σ more than other treatment procedures. CONCLUSION Post-sintering processes enabled an alteration in σ of zirconia. FP enhanced σ, while FPOG and FPHT resulted in a reduction of σ. Glazing tends to induce defects at the glazing interface, while heat treatment induces a phase change to tetragonal, both resulted in reducing σ. Finishing and polishing for both Cz and Hz monolithic zirconia is recommended, while overglazed or heat-treated is not suggested.
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Affiliation(s)
- Niwut Juntavee
- Department of Prosthodontics, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
| | - Apa Juntavee
- Department of Preventive Dentistry, Division of Pediatric Dentistry, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
| | - Thipradi Phattharasophachai
- Division of Biomaterials and Prosthodontics Research, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
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Jalali H, Mostafavi AS, Balaghi F. The Effect of Coloring Beverages on Color Stability of Hybrid Ceramics with Different Surface Treatments. PESQUISA BRASILEIRA EM ODONTOPEDIATRIA E CLÍNICA INTEGRADA 2022. [DOI: 10.1590/pboci.2022.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Surface and bulk properties of zirconia as a function of composition and aging. J Mech Behav Biomed Mater 2021; 126:104994. [PMID: 34864575 DOI: 10.1016/j.jmbbm.2021.104994] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/18/2021] [Accepted: 11/21/2021] [Indexed: 01/08/2023]
Abstract
Yttria-stabilized zirconia (Y-SZ) materials with different levels of translucency have been used for indirect dental restorations. Y-SZ composition and microstructure are modified to improve translucency, and it is not clear how these materials respond to aging. This study evaluated the effect of hydrothermal aging (HA) performed in an autoclave on the properties of four dental Y-SZ materials with different compositions. Sintered bar-shaped specimens (14 x 4 x 2 mm) were prepared from four different zirconia-based materials (n = 40): low translucency 3 mol % Y-SZ (3Y-LT; Ceramill ZI, Amann Girrbach); high translucency 4 mol % Y-SZ (4Y-HT; Ceramill Zolid); and two high translucency 5 mol % Y-SZ (5Y-HT - Lava Esthetic, 3M; 5Y-SHT - Ceramill Zolid FX). Fully sintered specimens were exposed to HA for different times (control - 0 h, 5 h, 10 h, or 15 h at 134 °C, 2 bar pressure) and characterized for surface roughness, flexural strength (three-point bending), hardness and elastic modulus (nanoindentation), surface wettability (sessile drop technique) and crystalline content (x-ray diffraction, XRD). Data was analyzed by two-way ANOVA and Tukey HSD (p < 0.05). Zirconia composition significantly affected roughness (p = 0.016). Zirconia*aging interaction affected flexural strength (p = 0.012), surface wettability (p < 0.001), and hardness (p = 0.002). Zirconia composition (p = 0.011) and aging (p = 0.001) affected elastic modulus, while the interaction effect was not significant (p = 0.94). HA affects zirconia-based materials in different degrees. For 3Y-LT and 4Y-HT, surface and bulk properties were affected by aging to a similar extent. However, surface and bulk properties may change during clinical use as a result of prolonged degradation of Y-SZ.
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Ziyad TA, Abu-Naba'a LA, Almohammed SN. Optical properties of CAD-CAM monolithic systems compared: three multi-layered zirconia and one lithium disilicate system. Heliyon 2021; 7:e08151. [PMID: 34712853 PMCID: PMC8529506 DOI: 10.1016/j.heliyon.2021.e08151] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 08/03/2021] [Accepted: 10/06/2021] [Indexed: 02/04/2023] Open
Abstract
Objective this in vitro investigation aims to evaluate and compare optical properties of three types of esthetic CAD-CAM monolithic multi-layered zirconia materials with a control (conventional lithium disilicate, IPS e. max CAD). Methods Four monolithic CAD-CAM ceramic materials were investigated: Ceramill Zolid® FX Multilayer (ZF), IPS e. max® ZirCAD MT Multi (ZM), Katana® STML (KS) and one lithium disilicate glass-ceramics as a control (IPS e. max® CAD LT; LC). A total of 72 (15 × 15 × 1 mm) samples were CAD CAM fabricated and sintered based on sample-size power calculations, and each material comprised 18 samples. The translucency and opalescence parameters with the contrast ratio were evaluated with a dental spectrophotometer over the backgrounds of black and white. The data were analyzed by ANOVA, then Bonferroni post hoc comparison test was made between groups. The statistical significance was set at p < 0.05. Results Zirconia materials revealed lower optical properties than the lithium disilicate control LC (P < 0.05). TP values ranged from 14.174 to 20.439. No differences were detected between the zirconia products in terms of TP and CR (P = 1.000). OP values ranged from 5.068 to 10.097. The lowest OP values were found statistically significant for ZF followed by KS and ZM (P = 1.000). LC had the highest TP and OP values, as well as the lowest CR (p < 0.05). Conclusions The optical properties of monolithic zirconia systems tested here are still lower than those of lithium disilicate glass-ceramics. The only difference observed between the monolithic CAD CAM zirconia materials, was for the low opalescence parameter for the ZF. Clinical significance Multi-layered monolithic zirconia systems have better esthetics by shade layers resembling natural tooth color gradients. CAD-CAM technology allowed for in-office milling and shaping of restorations using these systems. This study reports on their optical properties affecting human vision/perception of natural tooth shade to conclude about their use in the esthetic zones.
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Affiliation(s)
- Tareq A Ziyad
- PROSTHODONTICS Program, Department of Prosthodontics, Faculty of Dentistry, Jordan University of Science and Technology, Irbid, Jordan
| | - Layla A Abu-Naba'a
- Department of Prosthodontics, Jordan University of Science and Technology, Irbid, Jordan
| | - Saleh N Almohammed
- Department of Prosthodontics, Jordan University of Science and Technology, Irbid, Jordan
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SHAFIGH ELNAZ, ASHRAFI MEHRAN. A REVIEW OF MECHANICAL BEHAVIOR OF DENTAL CERAMIC RESTORATIONS. J MECH MED BIOL 2021. [DOI: 10.1142/s0219519421500639] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Dental ceramics are well known for restoring the function and aesthetic of lost or damaged teeth. Understanding these materials’ mechanical and aesthetic properties can make a suitable choice for those materials. The longevity of dental ceramics depends on several factors, including manufacturing method, clinical process, and the oral cavity’s aqueous environment. Failure mechanisms in restorative ceramics are complex and a combination of several factors. Different microstructures in the crystalline phase will involve the propagation of cracks and eventually the fatigue of ceramic materials. Large grains reduce mechanical performance compared to small grain sizes. Aesthetic materials used for veneering are weaker than the core materials and fail when even subjected to small loads. The soft bonding in the core–veneer interface and possible residual stresses created during the veneering method are drawbacks of these systems. Studies on the mechanical behavior of these materials have grown significantly in recent years and provide helpful information about static and fatigue experimentation and the failure behavior of various materials used in dental crowns.
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Affiliation(s)
- ELNAZ SHAFIGH
- Operative Dentistry Department, Faculty of Dentistry, AJA University of Medical Sciences, Tehran, Iran
| | - MEHRAN ASHRAFI
- Operative Dentistry Department, Faculty of Dentistry, AJA University of Medical Sciences, Tehran, Iran
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Juntavee N, Juntavee A, Phattharasophachai T. Fracture toughness of different monolithic zirconia upon post-sintering processes. J Clin Exp Dent 2021; 13:e1006-e1014. [PMID: 34667496 PMCID: PMC8501869 DOI: 10.4317/jced.58717] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 08/24/2021] [Indexed: 11/09/2022] Open
Abstract
Background Surface treatments are expected to be a reason for alteration in fracture resistance of zirconia. This study evaluated the effect of post-sintering processes on the fracture toughness of different types of monolithic zirconia.
Material and Methods Classical- (Cz) and high-translucent (Hz) monolithic zirconia discs (1.2 mm thickness, 14 mm in Ø) were prepared, and randomly divided for surface treatments with 1) as-glazed (AG); 2) finished and polished (FP); 3) finished, polished, and overglazed (FPOG); and 4) finished, polished, and heat-treated (FPHT) technique (n=15/group). Fracture toughness (KIC) was determined with indentation fracture toughness method at load 1 kg for AG, FPOG and 10 kg for FP, FPHT with 15 sec dwelling time. Weibull analysis was applied for survival probability, Weibull modulus (m), and characteristic toughness (K0). Microstructures were examined with SEM and XRD. ANOVA and multiple comparisons were determined for significant differences (α=0.05).
Results The mean±sd value of KIC (MPa.m1/2), m, and K0 were 1.60±0.19, 7.27, 1.71 for CzAG; 9.57±0.89, 9.97, 10.96 for CzFP; 1.61±0.15, 10.56, 1.68 for CzFPOG; 6.45±0.31, 20.31, 6.60 for CzFPHT; 1.45±0.13, 10.91, 1.51 for HzAG; 6.58±0.24, 27.00, 6.70 for HzFP; 1.24±0.05, 23.90, 1.27 for HzFPOG; and 5.07±0.16, 30.51, 5.15 for HzFPHT. The KIC was significantly affected by the post-sintering process, type of zirconia (p<0.05). The Cz indicated a significantly higher KIC than Hz. The FP significantly enhanced KIC, while OG was unable to raise KIC. HT reduced KIC due to reverse phase transformation.
Conclusions Post-sintering processes caused alteration in fracture resistance of zirconia. Fracture toughness was enhanced with FP, but not with either OG or HT process for both Cz and Hz. Surface treatment of zirconia through a finished-polished process is recommended, while glazing and heat-treated are not suggested. Key words:Fracture toughness, glazing, heat treatment, polishing, post-sintering process, zirconia.
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Affiliation(s)
- Niwut Juntavee
- Department of Prosthodontics, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
| | - Apa Juntavee
- Division of Pediatric Dentistry, Department of Preventive Dentistry, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
| | - Thipradi Phattharasophachai
- Division of Biomaterials and Prosthodontics Research, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
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Shelar P, Abdolvand H, Butler S. On the behaviour of zirconia-based dental materials: A review. J Mech Behav Biomed Mater 2021; 124:104861. [PMID: 34600431 DOI: 10.1016/j.jmbbm.2021.104861] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 09/23/2021] [Accepted: 09/24/2021] [Indexed: 11/28/2022]
Abstract
Zirconia-based dental materials are extensively used in clinical practice due to their tooth-like appearance, biofunctionality, biocompatibility, and affordability. However, premature clinical failures of veneering porcelains raise a concern about their integrity. Extensive studies have been performed over a decade to resolve this issue, but it is challenging to reference all information effectively. A single source identifying the significance of potential parameters on material performance has not previously been available. An evidence-based meta-narrative review technique was used to review the characteristic parameters that can affect the overall behaviour of zirconia-based materials. Keywords were chosen to assess manuscripts based on scientific coherence with this paper's research objective. Online keyword searches were carried out on ScienceDirect, PubMed, and SAGE databases for relevant published manuscripts from year 1985-2020.261 out of 3170 identified manuscripts were included. A total of 10 parameters were identified and classified into the material, manufacturing, and geometric aspects. The effect of every parameter was reviewed on the performance of the material. A discrepancy in findings was observed and is attributed to the fact that there is no standard methodology. This review acts as a single source that summarizes various parameters' contribution to zirconia-based dental materials' performance. This review facilitates manufacturing improvements by accounting for every parameter's effect on overall performance.
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Affiliation(s)
- Prashant Shelar
- Department of Mechanical & Materials Engineering, Western University, London, Ontario, Canada
| | - Hamidreza Abdolvand
- Department of Mechanical & Materials Engineering, Western University, London, Ontario, Canada
| | - Sheila Butler
- Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada.
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Zandinejad A, Das O, Barmak AB, Kuttolamadom M, Revilla-León M. The Flexural Strength and Flexural Modulus of Stereolithography Additively Manufactured Zirconia with Different Porosities. J Prosthodont 2021; 31:434-440. [PMID: 34580962 DOI: 10.1111/jopr.13430] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 09/01/2021] [Accepted: 09/09/2021] [Indexed: 11/28/2022] Open
Abstract
PURPOSE Additive manufacturing (AM) technologies are capable of fabricating complex geometries with different porosities. However, the effect of such porosities on mechanical properties of stereolithography (SLA) AM zirconia with different porosities is unclear. The purpose of this in vitro study was to investigate the mechanical properties namely flexural strength, and flexural modulus of AM zirconia with different porosities. MATERIALS AND METHODS A bar (25 × 4 × 3 mm) for flexural strength test (ISO standard 6872/2015) was designed by CAD software program and standard tessellation language (STL) file was obtained. The STL file was used to fabricate a total of 80 bars in four groups. Three experimental groups each containing 20 samples were manufactured using an SLA ceramic printer (CeraMaker 900; 3DCeram Co) and zirconia material (3DMix ZrO2 paste; 3DCeram Co) with different sintering post processing to achieve different porosities including 0%-porosity (AMZ0), 20%-porosity (AMZ20), and 40%-porosity (AMZ40). The same STL file was used for subtractive manufacturing or milling of 20 zirconia bars as control group (CNCZ) with the same dimensions using a commercial zirconia. Three-point bending tests were performed for all groups following ISO standard 6872/2015 specification using a universal testing machine. Outcomes measured included load at fracture, mean flexural strength, and flexural modulus and they were compared across the experimental groups using a one-way ANOVA. Post hoc pair wise comparison between each pair of the groups were performed using Tukey test. RESULTS There was a significant difference between the four groups, in terms of fracture load, flexural strength and flexural modulus using one-way ANOVA. AM zirconia with 0% porosity (AMZ0) showed the highest value for fracture load (1132.7 ± 220.6 N), flexural strength (755.1 ± 147.1 MPa) and flexural modulus (41,273 ± 2193 MPa) and AM zirconia with 40% porosity (AMZ40) showed the lowest fracture load (72.13 ± 13.42 N), flexural strength (48.09 ± 8.95 MPa) and flexural modulus (7177 ± 506 MPa). Tukey's pairwise comparisons detected a significant difference between all the possible pairs for all variables except flexural modulus between AMZ0 and CNCZ. The Weibull moduli presented the lowest value for AMZ20 (4.4) followed by AMZ40 (6.1), AMZ0 (6.1), and the highest value was for CNCZ (8.1). CONCLUSION AM zirconia with 0% porosity showed significantly higher flexural strength and flexural modulus when compared to milled and AM zirconia with 20% and 40% porosities.
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Affiliation(s)
| | - Omprakash Das
- College of Engineering, Texas A&M University, College Station, TX
| | | | | | - Marta Revilla-León
- College of Dentistry, Texas A&M University, Dallas, TX.,School of Dentistry, University of Washington, Seattle, WA.,Revilla Research Center, Madrid, Spain
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Manziuc MM, Gasparik C, Burde AV, Dudea D. Color and masking properties of translucent monolithic zirconia before and after glazing. J Prosthodont Res 2021; 65:303-310. [PMID: 33116028 DOI: 10.2186/jpr.jpr_d_20_00039] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Purpose 1. to assess the ability of four brands of translucent monolithic zirconia with different thicknesses to mask discolored substrates; 2. to assess the influence of glazing upon their color coordinates and masking properties.Methods Sixty samples of shade A1 (0.8, 1.5, and 2.0 mm thickness) from: ZirCAD/MT, Katana/HT, Vita YZ/HT, Cercon/HT were fabricated and glazed using a standardized laboratory procedure. CIE L*a*b* parameters were recorded on composite substrates, (IPS Natural Die Material Kit) (ND1=reference; ND2, ND3, ND4, ND5=test backgrounds), before and after glazing. The color changes of zirconia samples induced by glazing were analyzed. Masking properties was calculated as the color difference between CIE L*a*b* parameters of the samples placed on reference and test substrates with CIEDE2000(1:1:1) formula. The effect of material, thickness, substrate, and glazing on the color of monolithic zirconia was analyzed with ANOVA test and the multiple comparisons were analyzed with Tukey HSD tests (α=0.05).Results After glazing, lightness L* significantly increased, while chromatic coordinates a* and b* decreased (p<0.05). Significant differences in the masking properties of the four materials (p<0.001) were found, with IPS e.max ZirCAD/MT having the lowest masking effect (p<0.001). Thickness, substrate and glazing had a significant effect on the color masking properties of monolithic zirconia (p<0.001).Conclusions Masking properties of translucent zirconia were significantly influenced by the materials, the thickness and the color of the substrate; moreover, glazing improved the masking ability for all zirconia samples.
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Affiliation(s)
- Manuela Maria Manziuc
- Department of Prosthetic Dentistry and Dental Materials, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Cristina Gasparik
- Department of Prosthetic Dentistry and Dental Materials, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Alexandru Victor Burde
- Department of Prosthetic Dentistry and Dental Materials, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Diana Dudea
- Department of Prosthetic Dentistry and Dental Materials, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
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Çakmak G, Donmez MB, Kashkari A, Johnston WM, Yilmaz B. Effect of thickness, cement shade, and coffee thermocycling on the optical properties of zirconia reinforced lithium silicate ceramic. J ESTHET RESTOR DENT 2021; 33:1132-1138. [PMID: 34390305 PMCID: PMC9292539 DOI: 10.1111/jerd.12808] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 07/11/2021] [Accepted: 07/28/2021] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To investigate the effect of thickness, cement shade, and coffee thermocycling (CTC) on the optical properties of zirconia reinforced lithium silicate (ZLS) paired with different shades of a resin cement. MATERIALS AND METHODS Thirty ZLS specimens were prepared in two different thicknesses (0.8 and 1.5 mm) and three different resin cement shades (Tr, A2, and A3) were applied (n = 5). Color determinations were done before and after 5000 CTC by using a noncontact spectroradiometer. Color change due to CTC and relative translucency parameter (RTP) before and after CTC were calculated by using CIEDE2000. Data were analyzed using ANOVA and Bonferroni-corrected t-tests(α = 0.05). RESULTS Material thickness and resin cement shade (P < 0.001) affected baseline color. Material thickness affected color difference (P = 0.025). Thickness, resin cement shade, and CTC (P ≤ 0.0001) affected RTP. The difference between the color changes of the 0.8- and 1.5-mm specimens combined with A2 shade cement after CTC was significant (P = 0.01). RTPs of all pairs decreased after CTC (P < 0.001). CONCLUSIONS Cement shade and material thickness affected the baseline color. The thickness of ZLS affected the color change after CTC only with A2 resin cement and the color change was less when the ZLS was thicker. CTC reduced the translucency of all pairs. CLINICAL SIGNIFICANCE Clinicians and patients should be aware of a potential color change after long-term coffee consumption when zirconia reinforced lithium silicate is used particularly for laminate veneers with A2 shade of the tested resin cement.
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Affiliation(s)
- Gülce Çakmak
- Buser Foundation Scholar for Implant Dentistry, Department of Reconstructive Dentistry and Gerodontology, School of Dental MedicineUniversity of BernBernSwitzerland
| | - Mustafa Borga Donmez
- Department of ProsthodonticsBiruni University Faculty of DentistryIstanbulTurkey
| | - Afnan Kashkari
- Restorative and Esthetic DentistryJohns Hopkins Aramco HealthcareDhahranSaudi Arabia
| | - William M. Johnston
- Division of Restorative and Prosthetic DentistryThe Ohio State University College of DentistryColumbusOhio
| | - Burak Yilmaz
- Department of Reconstructive Dentistry and Gerodontology, School of Dental MedicineUniversity of Bern, BernSwitzerland
- Department of Restorative, Preventive and Pediatric Dentistry, School of Dental MedicineUniversity of BernBernSwitzerland
- Division of Restorative and Prosthetic DentistryThe Ohio State UniversityOhioUSA
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Oliveira AR, Jodha KS, Marocho SS, Galhano GA. Characterization of Reinforced and Unreinforced Glass-Ceramic Veneers. Oper Dent 2021; 46:339-347. [PMID: 34251455 DOI: 10.2341/20-067-l] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2020] [Indexed: 11/23/2022]
Abstract
This study aimed to characterize the surface topography, effect of polishing on surface roughness, residual stresses, and hardness in two glass-ceramic veneers. Fifty-two (52) upper incisors were collected, prepared, and scanned for ceramic veneers. Half of the teeth were restored with veneers made up of feldspathic ceramic (FE), and the other half with zirconia-reinforced lithium silicate ceramic (SZ). All the veneers were designed and milled using a CAD/CAM system and later cemented following the manufacturer's guideline. An optical microscope analyzed the topography of the specimens before and after polishing. The surface roughness was measured using the roughness meter (n=12) and the topographical analysis was carried out using an atomic force microscope (n=6). The residual stresses and Vickers' hardness were evaluated by the indentation method in a micro-hardness indenter (n=6). The surface roughness was analyzed using a three-way analysis of variance (ANOVA) followed by a post hoc Tukey test. The Student t-test was used to compare the residual stresses and hardness between the two ceramics. The topographical analysis revealed that both glass-ceramic veneers had similar percentages of specimens with cracks, before (34.6%) and after (42.3%) polishing. The surface roughness decreased after polishing (p<0.001), and the polishing smoothed out the surface of the veneers. The zirconia-reinforced lithium silicate veneer had a lower roughness as compared to the feldspathic one after polishing, while the residual stresses (p=0.722) and hardness (p=0.782) were statistically similar for both ceramic veneers.
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SEVMEZ H, YILMAZ H. Comparison Of The Effect Of Surface Conditioning Methods On The Bond Strength Of Different Zirconia Reinforced Lithium Silicate And Hybrid Ceramics To Resin Cement. CLINICAL AND EXPERIMENTAL HEALTH SCIENCES 2021. [DOI: 10.33808/clinexphealthsci.867710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Paken G, Yıldırım B, Ünal M, Tekeli A, Kırarslan Ö. Colour agreement between try-in paste and resin cement: effect of background on zirconia-reinforced lithium silicate. Aust Dent J 2021; 66:406-412. [PMID: 34212396 DOI: 10.1111/adj.12866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/25/2021] [Indexed: 11/27/2022]
Abstract
PURPOSE To investigate colour agreement between different shades of Panavia V5 resin cement and their try-in pastes under zirconia-reinforced lithium silicate ceramics. METHODS Forty-four zirconia-reinforced lithium silicate ceramic specimens were prepared at 0.8 ± 0.01 mm thickness. Composite resin tooth-shaded background specimens were obtained in two shades. Resin cement specimens were fabricated at 0.1-mm thickness. Colour difference values (ΔE) between Aquagel and both the try-in paste and resin cement were calculated using the CIE-Lab system. The CIEDE2000 (ΔE00) colour formula was used to determine colour differences. The three-way ANOVA test and a multiple comparisons test were used for statistical analysis (α = 0.05). RESULTS A statistically significant difference was found between the ΔE00 values obtained from the cement shade colour measurements for all specimens (P < 0.05). According to the three-way ANOVA test, lower ΔE00 values were observed in the try-in paste group compared to the resin cement group. The ΔE00 values were significantly affected by the cement shade and tooth-shaded background (P < 0.05). CONCLUSIONS The colour agreement between the try-in pastes and the corresponding resin cement differed, and the try-in pastes could not mask the dark dental background as much as the corresponding resin cement.
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Affiliation(s)
- G Paken
- School of Dentistry, Department of Prosthodontics, Usak University, Usak, Turkey
| | - B Yıldırım
- School of Dentistry, Department of Prosthodontics, Usak University, Usak, Turkey
| | - M Ünal
- School of Dentistry, Department of Prosthodontics, Usak University, Usak, Turkey
| | - A Tekeli
- School of Dentistry, Department of Prosthodontics, Usak University, Usak, Turkey
| | - Ö Kırarslan
- School of Dentistry, Department of Prosthodontics, Usak University, Usak, Turkey
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Too TDC, Inokoshi M, Nozaki K, Shimizubata M, Nakai H, Liu H, Minakuchi S. Influence of sintering conditions on translucency, biaxial flexural strength, microstructure, and low-temperature degradation of highly translucent dental zirconia. Dent Mater J 2021; 40:1320-1328. [PMID: 34193728 DOI: 10.4012/dmj.2020-448] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
There is limited research on the influence of different sintering temperatures on the properties of highly translucent zirconia ceramics. This study demonstrated the influence of different sintering temperatures on the translucency, crystallographic structure, biaxial flexural strength, microstructure, and low-temperature degradation (LTD) of three highly translucent zirconia grades, i.e., 3 mol% yttria-stabilized tetragonal zirconia polycrystals (3Y-TZP), 4 mol% yttria-partially-stabilized zirconia (4Y-PSZ), and 5 mol% yttria-PSZ (5Y-PSZ). The specimens were characterized using colorimetry, X-ray diffraction, scanning electron microscopy, Weibull analysis, and LTD tests (134°C; 20 h). The increase in the sintering temperature did not affect the translucency of 3Y-TZP, whereas it increased the translucencies of 4Y-PSZ and 5Y-PSZ. All the zirconia grades exhibited grain enlargement and unchanged biaxial flexural strengths with the increase in the sintering temperature. The degradation of 3Y-TZP and 4Y-PSZ at a sintering temperature of 1,600°C was faster than that at other sintering temperatures.
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Affiliation(s)
- Thaw Di Cho Too
- Department of Gerodontology and Oral Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Masanao Inokoshi
- Department of Gerodontology and Oral Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Kosuke Nozaki
- Department of Fixed Prosthodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Makoto Shimizubata
- Department of Gerodontology and Oral Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Hiroto Nakai
- Department of Gerodontology and Oral Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Hengyi Liu
- Department of Gerodontology and Oral Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Shunsuke Minakuchi
- Department of Gerodontology and Oral Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
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Mešić K, Majnarić I, Mehulić K. Effect of Aging on the Microstructure and Optical Properties of Translucent ZrO 2 Ceramics. Acta Stomatol Croat 2021; 55:114-128. [PMID: 34248145 PMCID: PMC8255040 DOI: 10.15644/asc55/2/1] [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: 03/30/2021] [Accepted: 05/31/2021] [Indexed: 02/04/2023] Open
Abstract
Objectives The development and placement of translucent zirconia ceramics on the dental materials market is in full swing. This research aimed to investigate how aging protocols affect the microstructure, color parameters and translucency of a new-generation monolithic zirconia ceramic. Material and methods Translucent zirconia ceramics KATANA-Zirconia STML with different surface treatments (as sintered - control, glazed, polished) was tested using two aging protocols (hydrothermal degradation in autoclave at 134 °C and 2 bars for three hours, chemical degradation in four-percent acetic acid at 80 °C for 16 hours) in order to examine phase composition using X-ray diffraction analysis and ΔE, ΔL and ΔC color parameters through spectrophotometry. The translucency parameter (TP) was calculated using parameters L*, a* and b* on a black and white surface. Results Regardless of the surface treatment, aging protocols did not cause a tetragonal-to-monoclinic phase transformation, although hydrothermal degradation in the autoclave transformed the hybrid tetragonal-cubic structure of all specimens to a tetragonal one. All polished and glazed specimens during chemical degradation demonstrated a significant color change ΔE. Lightness ΔL significantly changed in polished specimens aged in the autoclave. In all specimens, ΔC underwent a change manifested through statistically insignificant yellowing. None of the aging protocols altered the translucency of specimens. Conclusions Aging, regardless of the final surface treatment, did not manifest a monoclinic phase in the specimens. A tetragonal-cubic microstructure dominates. Unlike polishing, glazing the surface of translucent zirconia ceramics contributed to minor changes in color, lightness and chromaticity. The translucency of translucent zirconia ceramics remains stable regardless of aging and surface treatment.
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Affiliation(s)
- Korina Mešić
- DMD; Polyvalent Dental Office, 10 000 Zagreb, Croatia
| | - Igor Majnarić
- Associate Professor; Faculty of Graphic Arts, 10 000 Zagreb, Croatia
| | - Ketij Mehulić
- Professor; Dental Clinic, University Hospital Centre Zagreb, 10 000 Zagreb, Croatia
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Kim JE, Kwon YC, Kim S, Park YB, Shim JS, Moon HS. Effect of Acid Mixtures on Surface Properties and Biaxial Flexural Strength of As-Sintered and Air-Abraded Zirconia. MATERIALS 2021; 14:ma14092359. [PMID: 34062894 PMCID: PMC8125152 DOI: 10.3390/ma14092359] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/28/2021] [Accepted: 04/28/2021] [Indexed: 11/17/2022]
Abstract
The aim of this work was to evaluate the effects of application time of an acid mixture solution on the surface roughness, phase transformation, and biaxial flexural strength of 3Y-TZP after sintering or air abrasion. For the biaxial flexural strength measurement, 220 3Y-TZP disk-shaped specimens were prepared after as-sintering or air abrasion. The etching solution comprised a mixture of hydrofluoric acid, sulfuric acid, hydrogen peroxide, methyl alcohol, and purified water. The samples were divided into 11 subgroups according to the etching times (Control, 1, 2, 3, 5, 8, 10, 12, 15, 20, and 30 min). The results showed that acid treatment on both as-sintered and air-abraded 3Y-TZP surfaces increased the surface roughness. However, it had no significant effects on the monoclinic phase or flexural strength of as-sintered zirconia. The monoclinic phase and flexural strength of air-abraded zirconia increased sharply after air abrasion; however, they gradually decreased after acid treatment, to a similar level to the case of the untreated surface. Surface treatment with acid mixture increased the roughness, but the lack of increase of monoclinic phase is thought to be because the loose monoclinic particles remaining on the surface were removed through the etching process.
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Affiliation(s)
- Jong-Eun Kim
- Department of Prosthodontics, Yonsei University College of Dentistry, 50-1 Yonsei-Ro, SeodaemunGu, Seoul 03722, Korea; (J.-E.K.); (S.K.); (Y.-B.P.); (J.-S.S.)
| | - Yong-Chan Kwon
- CLF Dental Laboratory, 227 Moraenae-ro, Seodaemun Gu, Seoul 03695, Korea;
| | - Sunjai Kim
- Department of Prosthodontics, Yonsei University College of Dentistry, 50-1 Yonsei-Ro, SeodaemunGu, Seoul 03722, Korea; (J.-E.K.); (S.K.); (Y.-B.P.); (J.-S.S.)
| | - Young-Bum Park
- Department of Prosthodontics, Yonsei University College of Dentistry, 50-1 Yonsei-Ro, SeodaemunGu, Seoul 03722, Korea; (J.-E.K.); (S.K.); (Y.-B.P.); (J.-S.S.)
| | - June-Sung Shim
- Department of Prosthodontics, Yonsei University College of Dentistry, 50-1 Yonsei-Ro, SeodaemunGu, Seoul 03722, Korea; (J.-E.K.); (S.K.); (Y.-B.P.); (J.-S.S.)
| | - Hong-Seok Moon
- Department of Prosthodontics, Yonsei University College of Dentistry, 50-1 Yonsei-Ro, SeodaemunGu, Seoul 03722, Korea; (J.-E.K.); (S.K.); (Y.-B.P.); (J.-S.S.)
- Correspondence: ; Tel.: +82-2-2228-3155
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Wille S, Sieper K, Kern M. Wear resistance of crowns made from different CAM/CAD materials. Dent Mater 2021; 37:e407-e413. [PMID: 33875248 DOI: 10.1016/j.dental.2021.03.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 02/26/2021] [Accepted: 03/29/2021] [Indexed: 11/19/2022]
Abstract
OBJECTIVES The aim of this laboratory study was to evaluate the wear resistance of crowns made from current computer-aided design and computer-aided manufacture (CAD/CAM) materials. In addition, the abrasion of the steatite antagonist against these materials was compared. METHODS Identically shaped crowns of lithium disilicate, zirconia-reinforced lithium disilicate and a polymer-infiltrated ceramic network (PICN) were fabricated with an occlusal thickness of 1.5mm and a lateral wall thickness of 1.2mm (n=8). The crowns were cemented with a dual-polymerizing luting resin on composite resin dies. Using spherical steatite antagonists, all specimens were loaded with 49N for 1,200,000 cycles in a mastication simulator with additional thermocycling. After 120,000, 240,000, 480,000, 960,000, and 1,200,000 cycles, precision impressions were made and investigated with a laser scanning microscope. The vertical and volume substance loss was measured. Additionally, the substance loss of the antagonists was evaluated after 1,200,000 loading cycles. RESULTS No significant difference (p>0.05) was found in the median volume loss of the test materials after 1,200,000 cycles (lithium disilicate: 0.405mm3, PICN: 0.362mm3, zirconia-reinforced lithium disilicate: 0.340mm3). The vertical substance loss of PICN (157μm) was significantly lower (p≤0.05) than that of lithium disilicate (201μm) and zirconia reinforced lithium disilicate (191μm). However, the substance loss of steatite against zirconia-reinforced lithium disilicate (0.191mm3) was significantly lower (p≤0.05) than against lithium disilicate (0.296mm3) and PICN (0.531mm3). SIGNIFICANCE All three CAD/CAM materials showed wear resistance that seems appropriate for clinical application. Also, the abrasion of the antagonist looks promising.
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Affiliation(s)
- Sebastian Wille
- Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Christian-Albrechts University at Kiel, Germany.
| | - Kim Sieper
- Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Christian-Albrechts University at Kiel, Germany.
| | - Matthias Kern
- Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Christian-Albrechts University at Kiel, Germany.
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Koenig V, Bekaert S, Dupont N, Vanheusden A, Le Goff S, Douillard T, Chevalier J, Djaker N, Lamy de la Chapelle M, Amiard F, Dardenne N, Wulfman C, Mainjot A. Intraoral low-temperature degradation of monolithic zirconia dental prostheses: Results of a prospective clinical study with ex vivo monitoring. Dent Mater 2021; 37:1134-1149. [PMID: 33858665 DOI: 10.1016/j.dental.2021.03.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/25/2021] [Accepted: 03/29/2021] [Indexed: 02/04/2023]
Abstract
OBJECTIVE To investigate the intraoral development and kinetics of low-temperature degradation (LTD) in second-generation 3 mol.% yttria-doped tetragonal zirconia polycrystal (3Y-TZP) monolithic prostheses, as well as the influence of masticatory mechanical stress and glaze layer on it. METHODS A total of 101 posterior tooth elements were included in a prospective clinical study, which included ex vivo LTD monitoring (at baseline, 6 months, 1 year, and 2 years) using Raman spectroscopy (n = 2640 monoclinic phase measurement points per evaluation time) and SEM. Four types of areas (1-2 mm2 surface, 6 on molars, and 4 on premolars) were analyzed on each element surface: occlusal, axial, glazed, or unglazed. Raman depth mapping and high-resolution SEM were performed on the selected samples. RESULTS LTD developed in 3Y-TZP monolithic restorations 6 months after intraoral placement and progressed with time. After two years, the tetragonal-to-monoclinic transformation was non-uniform, with the presence of localized clusters of transformed grains. In axial areas, the grain aspect was typical of the classical nucleation-growth process reported for LTD, which progresses from the surface to a depth of several tens of microns. However, in occlusal areas, tribological stress generated surface crushing and grain pull-out from the clusters, which induced an underestimation of the aging process when the evaluation was limited to monoclinic phase quantification. Glazing cannot be considered a protection against LTD. SIGNIFICANCE If LTD occurs in dental prostheses in the same way as in orthopedic prostheses, its clinical impact is unknown and needs to be further studied.
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Affiliation(s)
- V Koenig
- Dental Biomaterials Research Unit (d-BRU), University of Liège (ULiège), 45 Quai G. Kurth, Liège, 4020, Belgium; Department of Fixed Prosthodontics, Institute of Dentistry, University of Liège Hospital (CHU), 45 Quai G. Kurth, Liège, 4020, Belgium
| | - S Bekaert
- Dental Biomaterials Research Unit (d-BRU), University of Liège (ULiège), 45 Quai G. Kurth, Liège, 4020, Belgium; Department of Fixed Prosthodontics, Institute of Dentistry, University of Liège Hospital (CHU), 45 Quai G. Kurth, Liège, 4020, Belgium
| | - N Dupont
- Dental Biomaterials Research Unit (d-BRU), University of Liège (ULiège), 45 Quai G. Kurth, Liège, 4020, Belgium; Department of Fixed Prosthodontics, Institute of Dentistry, University of Liège Hospital (CHU), 45 Quai G. Kurth, Liège, 4020, Belgium
| | - A Vanheusden
- Dental Biomaterials Research Unit (d-BRU), University of Liège (ULiège), 45 Quai G. Kurth, Liège, 4020, Belgium; Department of Fixed Prosthodontics, Institute of Dentistry, University of Liège Hospital (CHU), 45 Quai G. Kurth, Liège, 4020, Belgium
| | - S Le Goff
- Unité de Recherches en Biomatériaux Innovants et Interfaces (URB2i) - EA4462, Faculté de Chirurgie Dentaire, Université Paris Descartes, Sorbonne Paris-Cité, Montrouge, 92120, France
| | - T Douillard
- Université de Lyon, INSA Lyon, CNRS, MATEIS, UMR 5510, F-69621 Villeurbanne, France
| | - J Chevalier
- Université de Lyon, INSA Lyon, CNRS, MATEIS, UMR 5510, F-69621 Villeurbanne, France
| | - N Djaker
- Université Sorbonne Paris Nord, CNRS, UMR 7244, CSPBAT, Laboratoire de Chimie, Structures et Propriétés de Biomatériaux et d'Agents Thérapeutiques, 93017 Bobigny, France
| | - M Lamy de la Chapelle
- Institut des Molécules et Matériaux du Mans (IMMM - UMR6283), Université du Mans, avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France
| | - F Amiard
- Institut des Molécules et Matériaux du Mans (IMMM - UMR6283), Université du Mans, avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France
| | - N Dardenne
- Department of Public Health, University of Liège, 4000 Liège, Belgium
| | - C Wulfman
- Dental Biomaterials Research Unit (d-BRU), University of Liège (ULiège), 45 Quai G. Kurth, Liège, 4020, Belgium; Unité de Recherches en Biomatériaux Innovants et Interfaces (URB2i) - EA4462, Faculté de Chirurgie Dentaire, Université Paris Descartes, Sorbonne Paris-Cité, Montrouge, 92120, France
| | - A Mainjot
- Dental Biomaterials Research Unit (d-BRU), University of Liège (ULiège), 45 Quai G. Kurth, Liège, 4020, Belgium; Department of Fixed Prosthodontics, Institute of Dentistry, University of Liège Hospital (CHU), 45 Quai G. Kurth, Liège, 4020, Belgium.
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Influence of the foundation substrate on the fatigue behavior of bonded glass, zirconia polycrystals, and polymer infiltrated ceramic simplified CAD-CAM restorations. J Mech Behav Biomed Mater 2021; 117:104391. [PMID: 33618242 DOI: 10.1016/j.jmbbm.2021.104391] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 02/03/2021] [Accepted: 02/07/2021] [Indexed: 01/09/2023]
Abstract
This study evaluated the influence of distinct substrates on the mechanical fatigue behavior of adhesively cemented simplified restorations made of glass, polycrystalline or polymer infiltrated-ceramics. CAD/CAM ceramic blocks (feldspathic - FEL; lithium disilicate - LD; yttria-stabilized zirconia - YZ; and polymer-infiltrated ceramic network - PICN) were shaped into discs (n = 15, Ø = 10 mm; thickness = 1.0 mm), mimicking a simplified monolithic restoration. After, they were adhesively cemented onto different foundation substrates (epoxy resin - ER; or Ni-Cr metal alloy - MA) of the same shape (Ø = 10 mm; thickness = 2.0 mm). The assemblies were subjected to fatigue testing using a step-stress approach (200N-2800 N; step-size of 200 N; 10,000 cycles per step; 20 Hz) upon the occurrence of a radial crack or fracture. The data was submitted to two-way ANOVA (α = 0.05) to analyze differences considering 'ceramic material' and 'type of substrate' as factors. In addition, a survival analysis (Kaplan Meier with Mantel-Cox log-rank post-hoc tests; α = 0.05) was conducted to obtain the survival probability during the steps in the fatigue test. Fractographic and finite element (FEA) analyzes were also conducted. The factors 'ceramic material', 'type of substrate' and the interaction between both were verified to be statistically significant (p < .001). All evaluated ceramics presented higher fatigue failure load (FFL), cycles for failure (CFF) and survival probabilities when cemented to the metallic alloy substrate. Among the restorative materials, YZ and LD restorations presented the best fatigue behavior when adhesively cemented onto the metallic alloy substrate, while FEL obtained the lowest FFL and CFF for both substrates. The LD, PICN and YZ restorations showed similar fatigue performance considering the epoxy resin substrate. A more rigid foundation substrate improves the fatigue performance of adhesively cemented glass, polycrystalline and polymer infiltrated-ceramic simplified restorations.
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76
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Sasany R, Ergun-Kunt G, Yilmaz B. Effect of mouth rinses on optical properties of CAD-CAM materials used for laminate veneers and crowns. J ESTHET RESTOR DENT 2021; 33:648-653. [PMID: 33565723 DOI: 10.1111/jerd.12720] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 01/12/2021] [Accepted: 01/27/2021] [Indexed: 11/28/2022]
Abstract
OBJECTIVE The purpose of this study was to investigate the effect of mouth rinses on the color and translucency of three computer-aided design and computer-aided manufacturing (CAD-CAM) restorative materials in laminate veneer and crown thicknesses. METHODS Specimens from two different 5Y-TZP zirconia (InCoris TZI (IT), and Zirkonzahn (ZH)) and lithium disilicate (IPS e.max CAD [IC]) in two different thicknesses (0.7 mm for laminate veneer, and 1.5 mm for crown) were sectioned. All specimens were colored with an A2-shade liquid, and the baseline color values were recorded according to the CIELab system with a spectrophotometer. Each group was divided into two subgroups (n = 15) according to the immersion solution: two different mouth rinses, KL (Klorhex), and LI (Listerine, cool mint) for 180 hours. The color coordinates (L*, a*, b*) of the specimens were measured before and after immersion in a mouth rinse, and TP and ΔE00 color differences were calculated by using the CIEDE2000 color difference formula. A 3-way ANOVA, Bonferroni test, and 1-sample t tests were used to analyze the data (α = 0.05). RESULTS The 3-way ANOVA revealed a significant interaction of material, thickness, and mouth rinse for translucency parameter and color difference (ΔE00 ) data (p < 0.001). TP decreased for both zirconia materials in laminate veneer thickness when immersed in LI mouth rinse (p < 0.05). No difference was found among the TP mean values of three materials in crown thickness after immersed in mouth rinses (p > 0.826). Both zirconia materials immersed in LI showed greater discoloration than after immersed in KL (p < 0.05). A significant difference was found in color change values among three materials for the laminate veneer thickness after immersed in LI (p < 0.001). However, all color difference values were within the clinical acceptability threshold, except for when ZH in laminate veneer thickness was immersed in LI. CONCLUSIONS The color change of ZH zirconia with LI mouth rinse in laminate veneer thickness was high. For both zirconia ceramics, translucency decreased and the color was less stable in laminate veneer thickness after immersed in LI compared to the crown thickness. CLINICAL SIGNIFICANCE The results of this in vitro study suggest that long-term use of alcohol-containing mouth rinse may alter the optical properties of tested CAD-CAM materials in tested laminate veneer thickness. For color stability with the long term use of tested mouth rinses, lithium disilicate may be preferred for both types of restorations.
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Affiliation(s)
| | - Goknil Ergun-Kunt
- University of Ondokuz Mayıs, Faculty of Dentistry, Department of Prosthodontics, Samsun, Turkey
| | - Burak Yilmaz
- Departments of Reconstructive Dentistry and Gerodontology, and Restorative, Preventive, and Pediatric Dentistry, University of Bern School of Dental Medicine, Bern, Switzerland
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77
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Al-Haj Husain N, Dürr T, Özcan M, Brägger U, Joda T. Mechanical stability of dental CAD-CAM restoration materials made of monolithic zirconia, lithium disilicate, and lithium disilicate-strengthened aluminosilicate glass ceramic with and without fatigue conditions. J Prosthet Dent 2021; 128:73-78. [PMID: 33546860 DOI: 10.1016/j.prosdent.2020.12.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 12/03/2020] [Accepted: 12/04/2020] [Indexed: 10/22/2022]
Abstract
STATEMENT OF PROBLEM Studies investigating the mechanical stability of lithium disilicate-strengthened aluminosilicate glass ceramic that do not require sintering after milling compared with other computer-aided design and computer-aided manufacturing (CAD-CAM) materials are lacking. PURPOSE The purpose of this in vitro study was to investigate the flexural strength of CAD-CAM zirconia, lithium disilicate, and lithium disilicate-strengthened aluminosilicate glass ceramics with and without fatigue conditions. MATERIAL AND METHODS Specimens (N=90, n=15) (12×4×3 mm) from the following CAD-CAM materials were prepared and polished: lithium disilicate glass ceramic (IPS e.max CAD); lithium disilicate-strengthened aluminosilicate glass ceramic (N!ce); and zirconium dioxide ceramic (IPS e.max ZirCAD). All specimens were divided into 2 subgroups: immediate testing without aging and simulation of aging by using a mastication simulator for 1 200 000 cycles (5 °C-55 °C). Thereafter, flexural strength testing was performed by using a universal testing machine (1 mm/min) on nonaged and aged specimens. The data were evaluated by using nonparametric 2-way ANOVA and Wilcoxon rank post hoc tests (α=.05). RESULTS Both the material type and aging significantly affected the results (P<.001). The interaction was not significant (P>.05). Under nonaged conditions, zirconium dioxide ceramic (1136 ±162 MPa) showed significantly higher mean ±standard deviation flexural strength (P<.001) than lithium disilicate (304 ±34 MPa) and lithium disilicate-strengthened aluminosilicate glass ceramic (202 ±17 MPa). The glass ceramic groups were also significantly different from each other (P<.001). After aging, zirconium dioxide (1087.9 ±185.3 MPa) also presented significantly higher mean ±standard deviation flexural strength (P<.001) than lithium disilicate (259 ±62 MPa) and lithium disilicate-strengthened aluminosilicate glass ceramic (172 ±11 MPa) (P<.001). Aging significantly decreased the flexural strength of lithium disilicate (14.6%) (P=.03) and lithium disilicate-strengthened aluminosilicate glass ceramic (14.5%) (P=.01) but had minimal effect on the zirconium dioxide ceramic (4.3%) (P=.29). CONCLUSIONS Among the tested CAD-CAM materials, the mechanical performance of lithium disilicate-strengthened aluminosilicate glass ceramic was comparable with that of lithium disilicate and considerably lower than that of zirconia. Aging decreased the flexural strength of both lithium disilicate and lithium disilicate-strengthened aluminosilicate glass ceramic.
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Affiliation(s)
- Nadin Al-Haj Husain
- Specialization Candidate, Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland.
| | - Tobias Dürr
- Master student, School of Dental Medicine, University of Bern, Bern, Switzerland
| | - Mutlu Özcan
- Professor and Head, Division of Dental Biomaterials, Clinic for Reconstructive Dentistry, University of Zurich, Zurich, Switzerland
| | - Urs Brägger
- Professor, Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland
| | - Tim Joda
- Professor, Department of Reconstructive Dentistry, University Center for Dental Medicine Basel, University of Basel, Basel, Switzerland
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78
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Hasanzade M, Moharrami M, Alikhasi M. How adjustment could affect internal and marginal adaptation of CAD/CAM crowns made with different materials. J Adv Prosthodont 2021; 12:344-350. [PMID: 33489018 PMCID: PMC7790605 DOI: 10.4047/jap.2020.12.6.344] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 10/24/2020] [Accepted: 11/05/2020] [Indexed: 12/02/2022] Open
Abstract
PURPOSE Recently introduced hybrid and reinforced glass ceramic computer-aided design/computer-aided manufacturing (CAD/CAM) materials have been used for full-coverage restorations. However; the effect of adjustment and type of materials on internal and marginal adaptation are unknown. This study aimed to evaluate and compare the marginal and internal adaptations of crowns made of three different CAD/CAM materials before and after adjustment. MATERIALS AND METHODS One acrylic resin maxillary first molar was prepared and served as the master die. Thirty-six restorations were fabricated using CAD/CAM system (CEREC Omnicam, MCXL) with three materials including lithium disilicate (IPS e.max CAD), zirconia-reinforced lithium silicate (Suprinity), and hybrid ceramic (Enamic). Internal and marginal adaptations were evaluated with the reference point matching technique before and after adjustment. The data were analyzed using mixed ANOVA considering α=.05 as the significance level. RESULTS The effect of adjustment and its interaction with the restoration material were significant for marginal, absolute marginal, and occlusal discrepancies (P<.05). Before adjustment, Suprinity had lower marginal discrepancies than IPS e.max CAD (P=.18) and Enamic (P=.021); though no significant differences existed after adjustment. CONCLUSION Within the limitations of this study, crowns fabricated from IPS e.max CAD and Suprinity resulted in slightly better adaptation compared with Enamic crowns before adjustment. However, marginal, axial, and occlusal discrepancies were similar among all materials after the adjustment.
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Affiliation(s)
- Mahya Hasanzade
- Dental Research Center, Dentistry Research Institute, Department of Prosthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Moharrami
- Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Marzieh Alikhasi
- Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran
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Kazi GAS, Yamagiwa R. Cytotoxicity and biocompatibility of high mol% yttria containing zirconia. Restor Dent Endod 2020; 45:e52. [PMID: 33294417 PMCID: PMC7691258 DOI: 10.5395/rde.2020.45.e52] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 06/03/2020] [Accepted: 06/04/2020] [Indexed: 11/24/2022] Open
Abstract
Objectives Yttria-stabilized tetragonal phase zirconia has been used as a dental restorative material for over a decade. While it is still the strongest and toughest ceramic, its translucency remains as a significant drawback. To overcome this, stabilizing the translucency zirconia to a significant cubic crystalline phase by increasing the yttria content to more than 8 mol% (8YTZP). However, the biocompatibility of a high amount of yttria is still an important topic that needs to be investigated. Materials and Methods Commercially available 8YTZP plates were used. To enhance cell adhesion, proliferation, and differentiation, the surface of the 8YTZP is sequentially polished with a SiC-coated abrasive paper and surface coating with type I collagen. Fibroblast-like cells L929 used for cell adherence and cell proliferation analysis, and mouse bone marrow-derived mesenchymal stem cells (BMSC) used for cell differentiation analysis. Results The results revealed that all samples, regardless of the surface treatment, are hydrophilic and showed a strong affinity for water. Even the cell culture results indicate that simple surface polishing and coating can affect cellular behavior by enhancing cell adhesion and proliferation. Both L929 cells and BMSC were nicely adhered to and proliferated in all conditions. Conclusions The results demonstrate the biocompatibility of the cubic phase zirconia with 8 mol% yttria and suggest that yttria with a higher zirconia content are not toxic to the cells, support a strong adhesion of cells on their surfaces, and promote cell proliferation and differentiation. All these confirm its potential use in tissue engineering.
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Affiliation(s)
- Gulsan Ara Sathi Kazi
- Department of Biosystems Engineering, Graduate School of Science and Technology, Yamagata University, Yamagata, Japan
| | - Ryo Yamagiwa
- Department of Biosystems Engineering, Graduate School of Science and Technology, Yamagata University, Yamagata, Japan
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Bioinstructive Micro-Nanotextured Zirconia Ceramic Interfaces for Guiding and Stimulating an Osteogenic Response In Vitro. NANOMATERIALS 2020; 10:nano10122465. [PMID: 33317084 PMCID: PMC7764817 DOI: 10.3390/nano10122465] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 12/01/2020] [Accepted: 12/05/2020] [Indexed: 01/17/2023]
Abstract
Osseous implantology’s material requirements include a lack of potential for inducing allergic disorders and providing both functional and esthetic features for the patient’s benefit. Despite being bioinert, Zirconia ceramics have become a candidate of interest to be used as an alternative to titanium dental and cochlear bone-anchored hearing aid (BAHA) implants, implying the need for endowing the surface with biologically instructive properties by changing basic parameters such as surface texture. Within this context, we propose anisotropic and isotropic patterns (linear microgroove arrays, and superimposed crossline microgroove arrays, respectively) textured in zirconia substrates, as bioinstructive interfaces to guide the cytoskeletal organization of human mesenchymal stem cells (hMSCs). The designed textured micro-nano interfaces with either steep ridges and microgratings or curved edges, and nanoroughened walls obtained by direct femtosecond laser texturing are used to evaluate the hMSC response parameters and osteogenic differentiation to each topography. Our results show parallel micro line anisotropic surfaces are able to guide cell growth only for the steep surfaces, while the curved ones reduce the initial response and show the lowest osteogenic response. An improved osteogenic phenotype of hMSCs is obtained when grown onto isotropic grid/pillar-like patterns, showing an improved cell coverage and Ca/P ratio, with direct implications for BAHA prosthetic development, or other future applications in regenerating bone defects.
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81
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Dederichs M, Fahmy MD, An H, Guentsch A, Viebranz S, Kuepper H. Comparison of Wear Resistance of Prefabricated Composite Veneers Versus Ceramic and Enamel. J Prosthodont 2020; 30:711-719. [PMID: 33617152 DOI: 10.1111/jopr.13303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/02/2020] [Indexed: 11/30/2022] Open
Abstract
PURPOSE To measure surface roughness before and after wear-tests of two different prefabricated composite veneers and compare them to ceramic veneers and human dental enamel. MATERIALS AND METHODS Roughness (Ra-values) of two prefabricated composite veneers (Visalys Veneer Chairside (VIS) and Componeer (COM)) were compared to lithium disilicate Veneers (e.max CAD) and dental enamel (DENT) in vitro. In total n = 45 specimens per material and enamel samples were used for wear-tests. Wear-out tests were conducted by abrasion tests with a toothbrush simulator (22,000 strokes/ 100 g load; approximately equal to two years of cleansing) and erosion tests were carried out using citric acid (pH 1.57). Ra- and Sa-values were detected by white light interferometer before and after wear-tests. Data were analyzed with ANOVA followed by Games-Howell post hoc test and t-test (α = 0.05). RESULTS At baseline the lowest Ra- and Sa-values were found in VIS (Ra: 0.01 µm; Sa: 0.04 µm) while DENT revealed significantly higher surface roughness (Ra: 0.11 µm, p < 0.05; Sa: 0.30, p = 0.186). COM had significantly higher Ra-values (Ra: 0.10 µm; Sa: 0.22 µm) after abrasion, while e.max CAD was most resistant to the treatments (Ra: 0.01 µm, p < 0.05; Sa: 0.05 µm, p < 0.05). Compared to DENT all veneers were significantly less affected by citric acid (p < 0.001). CONCLUSIONS Prefabricated composite veneers have demonstrated less wear after abrasion and erosion tests compared to DENT, nevertheless, they revealed more wear compared to e.max CAD.
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Affiliation(s)
- Marco Dederichs
- Policlinic of Prosthetic Dentistry and Material Science, Centre for Dental Medicine, Jena University Hospital, Jena, D-07743, Germany
| | - Mina D Fahmy
- Department of Oral and Maxillofacial Surgery, University of Tennessee Medical Center, Knoxville, TN
| | - Hongseok An
- Department of General Dental Sciences, Marquette University School of Dentistry, Milwaukee, WI
| | - Arndt Guentsch
- Department of Surgical Sciences, Marquette University School of Dentistry, Milwaukee, WI
| | - Stephanie Viebranz
- Policlinic of Prosthetic Dentistry and Material Science, Centre for Dental Medicine, Jena University Hospital, Jena, D-07743, Germany
| | - Harald Kuepper
- Policlinic of Prosthetic Dentistry and Material Science, Centre for Dental Medicine, Jena University Hospital, Jena, D-07743, Germany
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82
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Cunico MWM. Investigation of Ceramic Dental Prostheses Based on ZrSiO 4-Glass Composites Fabricated by Indirect Additive Manufacturing. Int J Bioprint 2020; 7:315. [PMID: 33585712 PMCID: PMC7875056 DOI: 10.18063/ijb.v7i1.315] [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: 09/29/2020] [Accepted: 10/20/2020] [Indexed: 11/23/2022] Open
Abstract
Dental prosthesis and restoration technologies have been developed in the past years. Despite the advantages of additive manufacturing, computer-aided design, and computer-aided manufacturing technologies are still the dominant type of method for fabricating prostheses. Therefore, the main goal of this study is to assess the feasibility of using indirect fused deposition modeling to fabricate dental prosthesis made of ZrSiO4-glass composites. To achieve this goal, filaments were filled by 90% of ZrSiO4 and 50 μm glass spheres to fabricate prosthesis. Multivariable approach was applied to evaluate the feasibility of the proposed method. Holding temperature, holding time, heating rate, and cooling rate were considered the control factors, while shrinkage, flexural strength, and process feasibility were the study responses. In addition, the flexural strength of materials was found between 25 and 85 MPa, while shrinkage fluctuated between 10 and 25%.
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Affiliation(s)
- Marlon Wesley Machado Cunico
- Department of Mechanical Engineering, FAE University Center, Curitiba, Parana, Brazil.,Concep3D Research and Development, Curitiba, Parana, Brazil
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83
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de Carvalho ABG, Dal Piva AMDO, Tribst JPM, Werner A, Saavedra GDSFA, Kleverlaan CJ. Effect of microwave crystallization on the wear resistance of reinforced glass-ceramics. J Mech Behav Biomed Mater 2020; 111:104009. [DOI: 10.1016/j.jmbbm.2020.104009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/16/2020] [Accepted: 07/21/2020] [Indexed: 10/23/2022]
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Skjold A, Schriwer C, Gjerdet NR, Øilo M. Effect of artificial aging on high translucent dental zirconia: simulation of early failure. Eur J Oral Sci 2020; 128:526-534. [PMID: 33058363 DOI: 10.1111/eos.12739] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 09/04/2020] [Accepted: 09/10/2020] [Indexed: 01/02/2023]
Abstract
Higher yttria content enhances the translucency and appearance of dental zirconia materials. Alterations in material composition also affect mechanical properties. The aim of this study was to compare the fracture load after artificial short-term aging of monolithic, full-contour zirconia crowns with different amounts of yttria-stabilization. Sixty crowns (thirty super high translucent crowns (5Y-Z) and thirty high translucent crowns (3Y-Z)) were produced to fit a model of a premolar with a shallow chamfer preparation. The crowns were cemented with self-adhesive resin cement on composite abutments. For each zirconia type, three groups of crowns (n = 10) were allocated to: (i) cyclic loading (200 N, 1 Hz, 30,000 cycles), (ii) hydrothermal aging (3 × 20 min, 134°C 3.2 bar), or (iii) no treatment (control). Surviving crowns from the aging process were quasistatically loaded until fracture. The 3Y-Z crowns had statistically significantly higher fracture values (3,449 N) than the 5Y-Z crowns (1,938 N). The aging procedures did not affect load at fracture. Fractographic analysis showed that fractures started either at the crown margin or at the occlusal intaglio area. Higher yttria content leads to a reduction in material strength and damage tolerance, and this should be reflected in recommendations for clinical use.
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Affiliation(s)
- Anneli Skjold
- Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Bergen, Norway
| | - Christian Schriwer
- Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Bergen, Norway
| | - Nils R Gjerdet
- Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Bergen, Norway
| | - Marit Øilo
- Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Bergen, Norway
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85
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Oyar P, Durkan R, Deste G. Effects of sintering time and hydrothermal aging on the mechanical properties of monolithic zirconia ceramic systems. J Prosthet Dent 2020; 126:688-691. [PMID: 33039187 DOI: 10.1016/j.prosdent.2020.09.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/08/2020] [Accepted: 09/09/2020] [Indexed: 10/23/2022]
Abstract
STATEMENT OF PROBLEM The flexural strength of zirconia restorations is partially dependent on the sintering process. Changes in sintering protocols as well as hydrothermal aging may affect the flexural strength of zirconia materials. PURPOSE The purpose of this in vitro study was to investigate how changes in sintering parameters and hydrothermal aging affect the biaxial flexural strength of monolithic zirconia. MATERIAL AND METHODS Specimens were produced from 2 translucent monolithic zirconia ceramics (Zircon X ST, Upcera YZ HT). After coloring, specimens of both ceramics were distributed into groups and subjected to 1 of 6 different sintering protocols. Half were subjected to biaxial flexural strength tests directly after sintering, and the remaining specimens were subjected to hydrothermal aging and then to biaxial flexural strength testing. Biaxial flexural strength data were analyzed by using a statistical software program. Normality of distribution was determined by the Shapiro-Wilk test. Biaxial flexural strength data were compared among groups by using 1-way ANOVA and Tukey post hoc tests, and intragroup data were compared by using paired specimens t tests (α=.05). RESULTS The highest overall biaxial flexural strength value was obtained in UW-II. The highest biaxial flexural strength for Zircon X was obtained in ZX-VI and ZX-HTA-VI, whereas the highest biaxial flexural strength for Upcera was obtained in UW-II before hydrothermal aging and in UW-HTA-V after aging (P<.05). CONCLUSIONS The biaxial flexural strength of Zircon X increased with longer sintering times. Upcera specimens were more fracture-resistant than Zircon X both before and after hydrothermal aging. Based on these findings, longer sintering times are recommended to increase the strength of monolithic zirconia.
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Affiliation(s)
- Perihan Oyar
- Associate Professor, Department of Dental Prosthetics Technology, Vocational School of Health Services, Hacettepe University, Ankara, Turkey.
| | - Rukiye Durkan
- Associate Professor, Department of Prosthodontics, Faculty of Dentistry, Afyon Kocatepe University, Afyonkarahisar, Turkey
| | - Gonca Deste
- Assistant Professor, Department of Prosthodontics, Faculty of Dentistry, Bursa Uludağ University, Bursa, Turkey
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Microstructural, mechanical, and optical characterization of an experimental aging-resistant zirconia-toughened alumina (ZTA) composite. Dent Mater 2020; 36:e365-e374. [PMID: 32943230 DOI: 10.1016/j.dental.2020.08.010] [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: 02/12/2020] [Revised: 07/05/2020] [Accepted: 08/29/2020] [Indexed: 02/04/2023]
Abstract
OBJECTIVE To evaluate the effect of aging on the microstructural, mechanical, and optical properties of an experimental zirconia-toughened alumina composite with 80%Al2O3 and 20%ZrO2 (ZTA Zpex) compared to a translucent zirconia (Zpex) and Alumina. METHODS Disc-shaped specimens were obtained by uniaxial and isostatic pressing the synthesized powders (n = 70/material). After sintering and polishing, half of the specimens underwent aging (20 h, 134 °C, 2.2 bar). Crystalline content and microstructure were evaluated using X-ray diffraction and scanning electron microscopy, respectively. Specimens underwent biaxial flexural strength testing to determine the characteristic stress, Weibull modulus, and reliability. Translucency parameter (TP) and Contrast ratio (CR) were calculated to characterize optical properties. RESULTS ZTA Zpex demonstrated a compact surface with a uniform dispersion of zirconia particles within the alumina matrix, and typical alumina and zirconia crystalline content. ZTA Zpex and alumina exhibited higher CR and lower TP than Zpex. ZTA Zpex and Zpex showed significantly higher characteristic stress relative to alumina. While aging did not affect optical and mechanical properties of ZTA Zpex and alumina, Zpex demonstrated a significant increase in translucency, as well as a in characteristic stress. Alumina reliability was significantly lower than others at 300 MPa, ZTA Zpex and Zpex reliability decreased at 800 MPa, except for aged Zpex. SIGNIFICANCE While aging did not affect the mechanical nor the optical properties of ZTA Zpex and alumina, it did alter both properties of Zpex. The results encourage further investigations to engineer ZTA as a framework material for long span fixed dental prostheses specially where darkened substrates, such as titanium implant abutments or endodontically treated teeth, demand masking.
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87
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Oyar P, Durkan R, Deste G. The effect of the design of a mandibular implant-supported zirconia prosthesis on stress distribution. J Prosthet Dent 2020; 125:502.e1-502.e11. [PMID: 32893017 DOI: 10.1016/j.prosdent.2020.05.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 05/19/2020] [Accepted: 05/19/2020] [Indexed: 11/24/2022]
Abstract
STATEMENT OF PROBLEM Prosthetic complications have been frequently reported in implant-supported complete-arch prosthesis. Prosthetic restorations designed with an all-on-four treatment concept and fabricated from zirconia ceramic may be used to overcome these problems. PURPOSE The purpose of this biomechanical study was to evaluate the effects of cantilever length and inclination of implant on the stress distribution in bone tissue, implant, and a monolithic zirconia ceramic-lithium disilicate glass-ceramic superstructure for all-on-four prosthesis. MATERIAL AND METHODS All-on-four mandibular prosthesis fabricated from a zirconia and lithium disilicate glass-ceramic (LDGC) superstructure was designed with cantilever lengths of either 5 mm or 9 mm and posterior implants with a distal tilt of either 15 or 30 degrees. Stresses were evaluated with a simulated application of a static load of 600 N. RESULTS Increasing implant inclination from 15 to 30 degrees led to a decrease in maximum principal stress (MaxPS) values of approximately 4 to 7 MPa in cortical bone around all implants except the right anterior implant in the designs with short cantilevers and an increase in MaxPS values (approximately 3 to 19 MPa) in the same places in the designs with the long cantilevers. Increasing cantilever length from 5 to 9 mm resulted in an increase in minimum principal stress (MinPS) values of approximately 3 to 13 MPa in the cortical bone surrounding all posterior implants. In the designs with the long cantilever, MaxPS values increased approximately 3 to 4 MPa in spongy bone adjacent to the right posterior implant. An increase in cantilever length also led to higher vMS values at the first and second implant grooves in the right posterior implant in the design with the 15-degree implant tilt. An increase in implant inclination in the design with the short cantilever resulted in lower vMS values at the apex and all grooves of the left posterior implant, whereas in the design with the long cantilever, an increase in implant inclination resulted in lower stress values in the first and second grooves of the same implant. An increase in implant inclination led to in an increase in vMS values in the core structure. CONCLUSIONS In zirconia ceramic restorations by using an all-on-four design with an LDGC superstructure, short cantilevers may be preferable because they result in a more favorable distribution of stress than long cantilevers. An increase in implant angulation from 15 to 30 degrees decreased MaxPS values in cortical bone.
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Affiliation(s)
- Perihan Oyar
- Associate Professor, Dental Prosthetics Technology, Health Services Vocational School, Hacettepe University, Ankara, Turkey.
| | - Rukiye Durkan
- Associate Professor, Department of Prosthodontics, Faculty of Dentistry, Afyon Kocatepe University, Afyonkarahisar, Turkey
| | - Gonca Deste
- Assistant Professor, Department of Prosthodontics, Faculty of Dentistry, Bursa Uludağ University, Bursa, Turkey
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88
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Denry I, Dawson DV, Holloway JA. Crystalline phase evolution and thermal behavior of zirconia-lanthanum aluminate ceramics produced by surface modification. J Biomed Mater Res B Appl Biomater 2020; 109:328-337. [PMID: 32815316 DOI: 10.1002/jbm.b.34702] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 08/04/2020] [Indexed: 11/12/2022]
Abstract
The purpose of the present work was to investigate the effect doping with lanthanum aluminate on the phase assemblage and thermal behavior of zirconia ceramics for biomedical applications. Four compositions were prepared by a surface modification route of either conventional tetragonal zirconia (3Y-TZP) or high translucency cubic-based zirconia (5Y-PSZ) to reach a nominal composition of either 0.5 wt. % (3Y-0.5LAO and 5Y-0.5LAO) or 5 wt. % of lanthanum monoaluminate (3Y-5LAO and 5Y-5LAO). Undoped powders were used as controls. DTA and XRD analyses revealed that lanthanum dizirconate crystallized in the 934°C-936°C range, while lanthanum aluminate crystallized in the 1,056°C-1,063°C range in both types of zirconias doped at the 5% level. No second phase was found in compositions doped at the 0.5% level. The a lattice parameter and the amount of the cubic phase increased in both 3Y-5LAO and 5Y-5LAO. The microstructure of the compositions doped with 5% LAO was characterized by well distributed LAO twinned crystals and sparse needle-shaped lanthanum hexaaluminate crystals. A bimodal grain size distribution was observed in 5Y-doped compositions. This was attributed to abnormal grain growth of the cubic phase, and in line with aluminum segregation at grain boundaries and the presence of second-phase LAO crystals.
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Affiliation(s)
- Isabelle Denry
- Iowa Institute for Oral Health Research, University of Iowa College of Dentistry, Iowa City, Iowa, USA.,Department of Prosthodontics, University of Iowa College of Dentistry, Iowa City, Iowa, USA
| | - Deborah V Dawson
- Iowa Institute for Oral Health Research, University of Iowa College of Dentistry, Iowa City, Iowa, USA.,Department of Biostatistics, University of Iowa College of Public Health, Iowa City, Iowa, USA
| | - Julie A Holloway
- Department of Prosthodontics, University of Iowa College of Dentistry, Iowa City, Iowa, USA
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89
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Falahchai M, Babaee Hemmati Y, Neshandar Asli H, Neshandar Asli M. Marginal adaptation of zirconia‐reinforced lithium silicate overlays with different preparation designs. J ESTHET RESTOR DENT 2020; 32:823-830. [DOI: 10.1111/jerd.12642] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 07/21/2020] [Accepted: 07/30/2020] [Indexed: 12/01/2022]
Affiliation(s)
- Mehran Falahchai
- Dental Sciences Research Center, Department of Prosthodontics School of Dentistry, Guilan University of Medical Sciences Rasht Iran
| | - Yasamin Babaee Hemmati
- Dental Sciences Research Center, Department of Orthodontics School of Dentistry, Guilan University of Medical Sciences Rasht Iran
| | - Hamid Neshandar Asli
- Dental Sciences Research Center, Department of Prosthodontics School of Dentistry, Guilan University of Medical Sciences Rasht Iran
| | - Marzieh Neshandar Asli
- Undergraduate student, Dental School Anzali Campus, Guilan University of Medical Sciences Rasht Iran
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90
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Juntavee N, Uasuwan P. Flexural Strength of Different Monolithic Computer-Assisted Design and Computer-Assisted Manufacturing Ceramic Materials upon Different Thermal Tempering Processes. Eur J Dent 2020; 14:566-574. [PMID: 32791528 PMCID: PMC7535961 DOI: 10.1055/s-0040-1713957] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Objective
Strength of ceramics related with sintering procedure. This study investigated the influence of different tempering processes on flexural strength of three monolithic ceramic materials.
Materials and Methods
Specimens were prepared in bar-shape (width × length × thickness = 4 × 14 × 1.2 mm) from yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP, inCoris TZI [I]), zirconia-reinforced lithium silicate (ZLS, Vita Suprinity [V]), and lithium disilicate (LS
2
, IPS e.max CAD [E]), and sintered with different tempering processes: slow (S), normal (N), and fast (F) cooling procedure (
n
= 15/group). Flexural strength (σ
)
was determined using three-point bending test apparatus at 1 mm/min crosshead speed.
Statistical Analysis
The analysis of variance and Bonferroni’s multiple comparisons were determined for significant difference (α = 0.05). Weibull analysis was applied for survival probability, Weibull modulus (m), and characteristics strength (σ
o
). Microstructures were evaluated with scanning electron microscope and X-ray diffraction.
Results
The mean ± standard deviation (MPa) of σ, m, and σ
o
were: 1,183.98 ± 204.26, 6.23, 1,271.80 for IS; 1,084.43 ± 204.79, 5.76, 1,170.08 for IN; 777.19 ± 99.77, 8.78, 819.96 for IF; 267.15 ± 32.71, 9.11, 281.48 for VS; 218.43 ± 38.46, 6.40, 234.23 for VN; 252.67 ± 37.58, 7.20, 269.23 for VF; 392.09 ± 37.91, 11.37, 409.23 for ES; 378.88 ± 55.38, 7.45, 403.11 for EN, and 390.94 ± 25.34, 16.00, 403.51 for EF. Thermal tempering significantly affected flexural strength of Y-TZP (
p
< 0.05), but not either ZLS or LS
2
(
p
> 0.05). Y-TZP indicated significantly higher flexural strength upon slow tempering than others.
Conclusion
Enhancing flexural strength of Y-TZP can be achieved through slow tempering process and was suggested as a process for monolithic zirconia. Strengthening of ZLS and LS
2
cannot be accomplished through tempering; thus, either S-, N-, or F- tempering procedure can be performed. Nevertheless, to minimize sintering time, rapid thermal tempering is more preferable for both ZLS and LS
2
.
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Affiliation(s)
- Niwut Juntavee
- Department of Prosthodontics, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
| | - Pithiwat Uasuwan
- Division of Biomaterials and Prosthodontics Research, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
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91
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Alves DM, Cadore-Rodrigues AC, Prochnow C, Burgo TADL, Spazzin AO, Bacchi A, Valandro LF, Rocha Pereira GK. Fatigue performance of adhesively luted glass or polycrystalline CAD-CAM monolithic crowns. J Prosthet Dent 2020; 126:119-127. [PMID: 32636073 DOI: 10.1016/j.prosdent.2020.03.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 03/23/2020] [Accepted: 03/23/2020] [Indexed: 11/17/2022]
Abstract
STATEMENT OF PROBLEM Data comparing the fatigue performance of adhesively luted glass or polycrystalline ceramic systems for computer-aided design and computer-aided manufacturing (CAD-CAM) are scarce. PURPOSE The purpose of this in vitro study was to evaluate and compare the fatigue performance of monolithic crowns manufactured from glass or polycrystalline CAD-CAM ceramic systems adhesively luted to a dentin analog. MATERIALS AND METHODS Fifty-four pairs of standardized preparations of dentin analog (NEMA Grade G10) and simplified ceramic crowns of 1.5-mm thickness were obtained with 3 ceramic materials: lithium disilicate (LD) glass-ceramic (IPS e.max CAD); zirconia-reinforced lithium silicate (ZLS) glass-ceramic (Vita Suprinity); and translucent yttrium fully stabilized polycrystalline zirconia (Trans YZ) (Prettau Anterior). The simplified crowns (n=15) were adhesively cemented onto the preparations and subjected to step-stress fatigue test (initial load of 400 N, 20 Hz, 10 000 cycles, followed by 100-N increment steps until failure). Collected data (fatigue failure load [FFL] and cycles for failure [CFF]) were submitted to survival analysis with the Kaplan-Meier and Mantel-Cox post hoc tests (α=.05) and to Weibull analysis (Weibull modulus and its respective 95% confidence interval). Failed crowns were submitted to fractography analysis. The surface characteristics of the internal surface (roughness, fractal dimension) of additional crowns were accessed, and the occlusal cement thickness obtained in each luted system was measured. RESULTS Trans YZ crowns presented the highest values of FFL, CFF, and survival rates, followed by ZLS and LD (mean FFL: 1740 N>1187 N>987 N; mean CFF: 149 000>92 613>73 667). Weibull modulus and cement thickness were similar for all tested materials. LD presented the roughest internal surface, followed by ZLS (mean Ra: 226 nm>169 nm>93 nm). The LD and ZLS internal surfaces also showed higher fractal dimension, pointing to a more complex surface topography (mean fractal dimension: 2.242=2.238>2.147). CONCLUSIONS CAD-CAM monolithic crowns of Trans YZ show the best fatigue performance. In addition, ZLS crowns also showed better performance than LD crowns.
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Affiliation(s)
- Daniela Meira Alves
- Post-Graduate Program in Dentistry, School of Dentistry, Meridional Faculty, IMED, Passo Fundo, Rio Grande do Sul, Brazil
| | - Ana Carolina Cadore-Rodrigues
- PhD student, MSciD and PhD Post-Graduate Program in Oral Science (Prosthodontics Units), Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil
| | - Catina Prochnow
- MSciD and PhD Post-Graduate Program in Oral Science (Prosthodontics Units), Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil
| | - Thiago Augusto de Lima Burgo
- Adjunct Professor, Department of Physics, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil
| | - Aloísio Oro Spazzin
- Professor, Post-Graduate Program in Dentistry, School of Dentistry, Meridional Faculty, IMED, Passo Fundo, Rio Grande do Sul, Brazil
| | - Ataís Bacchi
- Professor, Post-Graduate Program in Dentistry, School of Dentistry, Meridional Faculty, IMED, Passo Fundo, Rio Grande do Sul, Brazil
| | - Luiz Felipe Valandro
- Professor, MSciD and PhD Post-Graduate Program in Oral Science (Prosthodontics Units), Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil
| | - Gabriel Kalil Rocha Pereira
- Adjunct Professor, MSciD and PhD Post-Graduate Program in Oral Science (Prosthodontics Units), Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil.
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92
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Falahchai M, Babaee Hemmati Y, Neshandar Asli H, Rezaei E. Effect of Tooth Preparation Design on Fracture Resistance of Zirconia‐Reinforced Lithium Silicate Overlays. J Prosthodont 2020; 29:617-622. [DOI: 10.1111/jopr.13160] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/05/2020] [Indexed: 11/28/2022] Open
Affiliation(s)
- Mehran Falahchai
- Dental Sciences Research Center, Department of Prosthodontics, School of DentistryGuilan University of Medical Sciences Rasht Iran
| | - Yasamin Babaee Hemmati
- Dental Sciences Research Center, Department of Orthodontics, School of DentistryGuilan University of Medical Sciences Rasht Iran
| | - Hamid Neshandar Asli
- Dental Sciences Research Center, Department of Prosthodontics, School of DentistryGuilan University of Medical Sciences Rasht Iran
| | - Elnaz Rezaei
- Dental Sciences Research Center, Department of Prosthodontics, School of DentistryGuilan University of Medical Sciences Rasht Iran
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93
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Benalcazar Jalkh EB, Monteiro KN, Cesar PF, Genova LA, Bergamo ETP, Lopes ACDO, Lima E, Lisboa-Filho PN, Campos TMB, Witek L, Coelho PG, Borges AFS, Bonfante EA. Aging resistant ZTA composite for dental applications: Microstructural, optical and mechanical characterization. Dent Mater 2020; 36:1190-1200. [PMID: 32561117 DOI: 10.1016/j.dental.2020.05.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Revised: 05/03/2020] [Accepted: 05/24/2020] [Indexed: 02/04/2023]
Abstract
OBJECTIVE To synthesize a zirconia toughened alumina (ZTA) composite with 70% alumina reinforced by 30% zirconia for dental applications and to characterize its microstructure and optical properties for comparison with the isolated counterpart materials and a first-generation 3Y-TZP. METHODS Disc-shaped specimens were divided in four groups (n = 70/material): (1) 3YSB-E (first generation 3Y-TZP), (2) Zpex (second generation 3Y-TZP), (3) alumina, and (4) ZTA-Zpex 70/30. After synthesis, ceramic powders were pressed, and green-body samples sintered following a predetermined protocol. Specimens were polished to obtain a mirror surface finish. Apparent density was measured by Archimedes principle. X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to characterize the crystalline content and microstructure. Reflectance tests were performed to determine the contrast-ratio (CR) and translucency-parameter (TP). Mechanical properties were assessed by biaxial flexural strength (BFS) test. All analyses were conducted before and after artificial aging (20 h, 134 °C, 2.2 bar). Optical parameters were evaluated through repeated-measures analysis of variance and Tukey tests (p < 0.05). BFS data were analyzed using Weibull statistics (95% CI). RESULTS High density values (95-99%) were found for all ceramic materials and SEM images exhibited a dense microstructure. While XRD patterns revealed the preservation of crystalline content in the ZTA composite, an increase in the monoclinic peak was observed for pure zirconias after aging. Significantly higher CR and lower TP values were observed for the ZTA composite, followed by alumina, 3YSB-E, and Zpex. The highest characteristic stress was recorded for 3YSB-E, followed by intermediate values between ZTA and Zpex, and the lowest for alumina. Aging affected the optical and mechanical properties of both zirconias, while remained stable for ZTA composite and alumina. SIGNIFICANCE The synthesis of experimental 70-30% ZTA composite was successful and its relevance for dental applications relies on its higher masking ability, aging resistance, and strength similar to zirconia.
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Affiliation(s)
- Ernesto Byron Benalcazar Jalkh
- Department of Prosthodontics and Periodontology, University of São Paulo, Bauru School of Dentistry, Bauru, SP, Brazil; Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, NY, USA.
| | - Kelli Nunes Monteiro
- Department of Biomaterials and Oral Biology, University of São Paulo, School of Dentistry, SP, Brazil
| | - Paulo Francisco Cesar
- Department of Biomaterials and Oral Biology, University of São Paulo, School of Dentistry, SP, Brazil
| | | | - Edmara T P Bergamo
- Department of Prosthodontics and Periodontology, University of São Paulo, Bauru School of Dentistry, Bauru, SP, Brazil
| | | | - Erick Lima
- Department of Biomaterials and Oral Biology, University of São Paulo, School of Dentistry, SP, Brazil
| | | | | | - Lukasz Witek
- Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, NY, USA; Department of Biomedical Engineering, New York University, Tandon School of Engineering, Brooklyn, NY, USA
| | - Paulo G Coelho
- Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, NY, USA; Hansjörg Wyss Department of Plastic Surgery, NYU Langone Medical Center, New York, NY, USA; Mechanical and Aerospace Engineering, NYU Tandon School of Engineering, New York, NY, USA
| | - Ana Flavia Sanches Borges
- Department of Operative Dentistry, Endodontics and Dental Materials, University of São Paulo - Bauru School of Dentistry, Bauru, SP, Brazil
| | - Estevam A Bonfante
- Department of Prosthodontics and Periodontology, University of São Paulo, Bauru School of Dentistry, Bauru, SP, Brazil
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94
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Survival probability of zirconia-reinforced lithium silicate ceramic: Effect of surface condition and fatigue test load profile. Dent Mater 2020; 36:808-815. [DOI: 10.1016/j.dental.2020.03.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 09/07/2019] [Accepted: 03/30/2020] [Indexed: 11/18/2022]
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95
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Fiorin L, Moris ICM, Faria ACL, Ribeiro RF, Rodrigues RCS. Effect of different grinding protocols on surface characteristics and fatigue behavior of yttria-stabilized zirconia polycrystalline: An in vitro study. J Prosthet Dent 2020; 124:486.e1-486.e8. [PMID: 32446636 DOI: 10.1016/j.prosdent.2020.03.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 03/10/2020] [Accepted: 03/11/2020] [Indexed: 11/17/2022]
Abstract
STATEMENT OF PROBLEM Zirconia frameworks milled by computer-aided design and computer-aided manufacturing (CAD-CAM) often require clinical adjustments. In addition, zirconia prefabricated abutments can also require customization to achieve an adequate emergence profile. However, the influence of grinding adjustment on the surface characteristics and mechanical behavior of yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) and the best grinding protocol is unclear. PURPOSE The purpose of this in vitro study was to evaluate the effect of different grinding protocols on the surface characteristics, phase transformation, and mechanical behavior of Y-TZP for frameworks and implant abutments. MATERIAL AND METHODS Bar-shaped specimens were fabricated according to ISO 6872-2016 and divided into 3 groups: GC (control, untreated), GA (grinding and finishing with medium and fine diamond rotary instruments using high-speed handpiece under constant water cooling), and GB (grinding and finishing with coarse and medium diamond rotary instruments, respectively, using slow-speed handpiece without water cooling). After specimen grinding, the topography and surface roughness were evaluated by using a laser confocal microscope, the Young modulus was measured by the impulse excitation technique, and crystallographic phase transformation was analyzed by X-ray diffraction. Specimens were then submitted to step-stress accelerated life testing (n=18). The surface roughness and Young modulus results were analyzed by 1-way ANOVA and the Tukey honestly significant difference test (α=.05). The data of step-stress accelerated life testing were analyzed by the survival probability considering the number of cycles and force until fracture. RESULTS Statistically significant differences were found among groups considering surface roughness (GA>GB>GC) (P<.05) and Young modulus (GB>GA=GC) (P=.003). X-ray diffraction showed that grinding leads to phase transformation, GC showed only tetragonal phase, while GA and GB showed tetragonal and monoclinic phases. No statistically significant difference (P<.05) was found among groups submitted to the same loading profile when the survival probability was compared, but significant difference was found between the light and moderate loading (P=.002) and light and severe loading (P=.014) of GB when different loading profiles in each group were compared. CONCLUSIONS Although grinding protocols affected surface characteristics and promoted phase transformation, the mechanical behavior of Y-TZP was not impaired. Therefore, both the grinding protocols tested can be safely used based on the evaluated properties.
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Affiliation(s)
- Lívia Fiorin
- Graduate student, Department of Dental Materials and Prosthodontics, Dental School of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Izabela C M Moris
- Former graduate, Department of Dental Materials and Prosthodontics, Dental School of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Adriana C L Faria
- Laboratory specialist, Department of Dental Materials and Prosthodontics, Dental School of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Ricardo F Ribeiro
- Professor, Department of Dental Materials and Prosthodontics, Dental School of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Renata C S Rodrigues
- Professor, Department of Dental Materials and Prosthodontics, Dental School of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil.
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96
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Sanal FA, Kilinc H. Effect of shade and sintering temperature on the translucency parameter of a novel multi-layered monolithic zirconia in different thicknesses. J ESTHET RESTOR DENT 2020; 32:607-614. [PMID: 32445503 DOI: 10.1111/jerd.12598] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 04/02/2020] [Accepted: 05/06/2020] [Indexed: 11/29/2022]
Abstract
OBJECTIVE The objective of the present research was to evaluate the effect of sintering temperatures (1350°C, 1450°C, and 1600°C) of a novel multi-layered esthetic zirconia material (Katana 12Z/STML) on the grain sizes and on the translucency parameters (TP00 ) for 2 different shades (A2-A3) and 2 different thicknesses (1-1.5 mm). MATERIAL AND METHODS A total of 120 non-sintered specimens were randomly divided into three subgroups according to sintering temperatures. The TP00 and grain sizes of the sintered specimens were calculated. Statistical analyses were performed using 3-way ANOVA, 1-way ANOVA, and Tukey's post hoc tests. RESULTS TP00 increased 1.2 to 1.5 times as the specimen thickness decreased from 1.5 to 1 mm (P ≤ .05). The lowest TP00 values were recorded for sintering at 1350°C for the investigated thicknesses and shades (P ≤ .05). The interaction of sintering temperature and shade was significant (P ≤ .05). Grain sizes were ordered according to sintering temperature as 1350°C < 1450°C < 1600°C (P ≤ .05). CONCLUSIONS TP00 values decreased with the increase in the thickness of the monolithic zirconia. The sintering temperatures and their interaction with shade significantly affected TP00 values. The grain size increased with increasing sintering temperature. CLINICAL SIGNIFICANCE The translucency of a novel multi-layered monolithic zirconia increased with higher sintering temperatures and lower thickness. The grain size increased with the increase in the sintering temperature. The sintering temperature of 1600°C led to a significant change in translucency for shade A3.
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Affiliation(s)
- Fatma A Sanal
- Department of Prosthodontics, Bolu Abant Izzet Baysal University, Faculty of Dentistry, Bolu, Turkey
| | - Hamiyet Kilinc
- Department of Prosthodontics, Bolu Abant Izzet Baysal University, Faculty of Dentistry, Bolu, Turkey
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97
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Sismanoglu S, Yildirim-Bilmez Z, Erten-Taysi A, Ercal P. Influence of different surface treatments and universal adhesives on the repair of CAD-CAM composite resins: An in vitro study. J Prosthet Dent 2020; 124:238.e1-238.e9. [PMID: 32376031 DOI: 10.1016/j.prosdent.2020.02.029] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 02/17/2020] [Accepted: 02/17/2020] [Indexed: 11/29/2022]
Abstract
STATEMENT OF PROBLEM The repairability of computer-aided design and computer-aided manufacturing (CAD-CAM) composite resins might be adversely affected by the high degree of matrix polymerization that occurs during their manufacturing process. However, information on their repairability is lacking. PURPOSE The purpose of this in vitro study was to evaluate the microtensile bond strength of CAD-CAM composite resins subjected to simulated repair procedures by using varying surface treatments and universal adhesives. MATERIAL AND METHODS Four different CAD-CAM blocks (Brilliant Crios, Lava Ultimate, Shofu Block HC, and Vita Enamic) were thermocycled (5000 times, 5/55 °C) and divided into 4 groups according to the surface treatment: control, 9% hydrofluoric acid etching, aluminum oxide airborne-particle abrasion, and tribochemical silica airborne-particle abrasion. After surface treatments, the surface roughness was measured with a nanoindenter and further examined with scanning electron microscopy. After the application of 3 different universal adhesives (Clearfil Universal Bond, Prime&Bond Universal, and Single Bond Universal), the specimens were subjected to a simulated repair process with composite resin. Bonded specimens were cut into 1 mm2 beams, and microtensile bond strength values were determined until failure at a crosshead speed of 0.5 mm/min. The bond strength data were analyzed with 3-way analysis of variance, and surface roughness data were analyzed with 2-way analysis of variance tests. Pairwise analyses were performed with the Tukey test (α=.05). RESULTS All surface treatments effectively improved repair microtensile bond strength values compared with the control (P<.05). Aluminum oxide airborne-particle abrasion had similar mean bond strength values compared with tribochemical silica airborne-particle abrasion (P>.05). Among the CAD-CAM blocks treated with hydrofluoric acid etching, Vita Enamic had the highest mean bond strength values. The highest mean microtensile bond strength repair values with the highest cohesive failure rates were found with the silane-containing universal adhesive (Single Bond Universal). CONCLUSIONS Surface treatment with aluminum oxide airborne-particle abrasion and tribochemical silica airborne-particle abrasion produced successful repair results for aged resin nanoceramics, whereas hydrofluoric acid etching can be used for aged hybrid ceramic repair. Silane-containing universal adhesive reported increased bond strength. Application of universal adhesive after surface treatment is recommended to increase repair strength.
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Affiliation(s)
- Soner Sismanoglu
- Assistant Professor, Department of Restorative Dentistry, School of Dentistry, University of Altinbas, Istanbul, Turkey.
| | - Zuhal Yildirim-Bilmez
- Assistant Professor, Department of Restorative Dentistry, School of Dentistry, University of Hatay Mustafa Kemal, Hatay, Turkey
| | - Aysegul Erten-Taysi
- Assistant Professor, Department of Oral and Maxillofacial Surgery, School of Dentistry, University of Altinbas, Istanbul, Turkey
| | - Pınar Ercal
- Assistant Professor, Department of Oral and Maxillofacial Surgery, School of Dentistry, University of Altinbas, Istanbul, Turkey
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Zucuni CP, Ilha BD, May MM, May LG, Valandro LF. Grinding the intaglio surface of yttria partially- and fully-stabilized zirconia polycrystals restorations: Effect on their fatigue behavior. J Mech Behav Biomed Mater 2020; 109:103800. [PMID: 32347216 DOI: 10.1016/j.jmbbm.2020.103800] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 04/09/2020] [Accepted: 04/12/2020] [Indexed: 11/20/2022]
Abstract
This study evaluated the effects of diamond bur grinding the intaglio surface of second (yttria partially-stabilized zirconia polycrystals, PSZ) and third-generation zirconia (fully-stabilized zirconia polycrystals, FSZ) adhesively cemented to dentin analogue substrate on the fatigue failure load, cycle number until failure, surface micromorphology and phase transformation. Disc-shaped specimens were produced from second (Katana ML-HT, Kuraray) and third-generation zirconia (Katana STML, Kuraray) and randomly allocated (n = 15) into two groups according to the intaglio surface treatment: Control - Ctrl (without grinding); Grinding - Gr (grinding at the center of the intaglio surface). The ceramic discs were adhesively cemented (Multilink Automix System) onto dentin analogue discs. Fatigue tests were executed by the step-stress method. The obtained data were analyzed by Kaplan Meier and Mantel-Cox tests. In addition, surface topography, roughness, phase transformation and fractography analyses were performed. SEM analysis showed that grinding increased the surface roughness and introduced defects in zirconia from both generations. Grinding increased the fatigue failure load, number of cycles to failure and survival rates of the second-generation zirconia statistically (control: 1373.33 N < grinding: 1600 N), while these same outcomes were reduced by grinding for the third-generation zirconia significantly (control: 766.67 N > grinding: 620 N). Thus, clinical adjustments with diamond burs damage the fatigue behavior of adhesively cemented third-generation zirconia.
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Affiliation(s)
- Camila Pauleski Zucuni
- Faculty of Odontology, Federal University of Santa Maria, Santa Maria, State of Rio Grande do Sul, Brazil.
| | - Bruna Dias Ilha
- Faculty of Odontology, Federal University of Santa Maria, Santa Maria, State of Rio Grande do Sul, Brazil.
| | - Michele Mirian May
- Faculty of Odontology, Federal University of Santa Maria, Santa Maria, State of Rio Grande do Sul, Brazil.
| | - Liliana Gressler May
- Faculty of Odontology, Federal University of Santa Maria, Santa Maria, State of Rio Grande do Sul, Brazil.
| | - Luiz Felipe Valandro
- Faculty of Odontology, Federal University of Santa Maria, Santa Maria, State of Rio Grande do Sul, Brazil.
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Ceramic Materials and Technologies Applied to Digital Works in Implant-Supported Restorative Dentistry. MATERIALS 2020; 13:ma13081964. [PMID: 32331379 PMCID: PMC7216107 DOI: 10.3390/ma13081964] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/14/2020] [Accepted: 04/20/2020] [Indexed: 12/17/2022]
Abstract
Computer-aided design and manufacturing technology has been closely associated with implant-supported restoration. The digital system employed for prosthodontic restorations comprises data acquisition, processing, and manufacturing using subtractive or additive methods. As digital implantology has developed, optical scanning, computer-based digital algorithms, fabricating techniques, and numerical control skills have all rapidly improved in terms of their accuracy, which has resulted in the development of new ceramic materials with advanced esthetics and durability for clinical application. This study reviews the application of digital technology in implant-supported dental restoration and explores two globally utilized ceramic restorative materials: Yttria-stabilized tetragonal zirconia polycrystalline and lithium disilicate glass ceramics.
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100
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Survival Probability, Weibull Characteristics, Stress Distribution, and Fractographic Analysis of Polymer-Infiltrated Ceramic Network Restorations Cemented on a Chairside Titanium Base: An In Vitro and In Silico Study. MATERIALS 2020; 13:ma13081879. [PMID: 32316360 PMCID: PMC7216243 DOI: 10.3390/ma13081879] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 04/08/2020] [Accepted: 04/10/2020] [Indexed: 02/07/2023]
Abstract
Different techniques are available to manufacture polymer-infiltrated ceramic restorations cemented on a chairside titanium base. To compare the influence of these techniques in the mechanical response, 75 implant-supported crowns were divided in three groups: CME (crown cemented on a mesostructure), a two-piece prosthetic solution consisting of a crown and hybrid abutment; MC (monolithic crown), a one-piece prosthetic solution consisting of a crown; and MP (monolithic crown with perforation), a one-piece prosthetic solution consisting of a crown with a screw access hole. All specimens were stepwise fatigued (50 N in each 20,000 cycles until 1200 N and 350,000 cycles). The failed crowns were inspected under scanning electron microscopy. The finite element method was applied to analyze mechanical behavior under 300 N axial load. Log-Rank (p = 0.17) and Wilcoxon (p = 0.11) tests revealed similar survival probability at 300 and 900 N. Higher stress concentration was observed in the crowns’ emergence profiles. The MP and CME techniques showed similar survival and can be applied to manufacture an implant-supported crown. In all groups, the stress concentration associated with fractographic analysis suggests that the region of the emergence profile should always be evaluated due to the high prevalence of failures in this area.
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