Resin-matrix ceramics for occlusal veneers: Effect of thickness on reliability and stress distribution

Author(s)

Ruggiero, Mirelle Maria ^[1] ; Gomes, Rafael Soares ^[1] ; Bergamo, Edmara Tatiely Pedroso ^[2] ; Freitas, Mariana Itaborai Moreira ^[1] ; Bonfante, Estevam Augusto ^[2] ; Cury, Altair Antoninha Del Bel ^[1]

Affiliation

^[1] Univ Estadual Campinas, Dept Prosthodont & Periodontol, Piracicaba Dent Sch, Limeira Ave 901, BR-13414903 Piracicaba, SP - Brazil

^[2] Univ Sao Paulo, Dept Prosthodont & Periodontol, Bauru Sch Dent, Dr Octavio Pinheiro Brisolla Ave 9-75, BR-17012901 Bauru, SP - Brazil

• Document type: Journal article
• Source: Dental Materials; v. 37, n. 3, p. E131-E139, MAR 2021.
• Web of Science Citations: 0

Abstract

Objective. To evaluate the influence of resin-matrix ceramic material and thickness on reliability and stress distribution of occlusal veneers (OV). Methods. One hundred and twenty-six OV of a mandibular first molar were milled using a CAD/CAM system and allocated according to materials (resin nanoceramic (RNC) orpolymer-infiltrated ceramic network (PICN)) and thicknesses (0.5, 1.0 and 1.5 mm), totaling six groups (RNC0.5, RNC1, RNC1.5, PICN0.5, PICN1, and PICN1.5). Step-stress accelerated-life testingwas performed (n = 21/group) with the load applied at the distobuccal cusp tip of the occlusal veneer until failure or suspension. The use level probability Weibull curves and reliability were calculated and plotted (90% CI). Finite element analysis evaluated the stress distribution according to maximum principal stress (sigma(max)) on the restoration and maximum shear stress (tau(max)) on the cement layer. Results. There was no difference in the probability of survival for the estimated missions among the groups, except at 600 N in which the results were significantly lower to PICN1.5 (6%) compared to RNC1 (55%) and RNC1.5 (60%). The sigma(max) values were higher for PICN (31.85-48.63 MPa) than RNC (30.78-33.09 MPa) in the same thicknesses. In addition, 0.5 mm groups concentrated more stress in the restoration (33.09-48.63 MPa) than 1.0 mm (31.11-35.36 MPa) and 1.5 mm (30.78-31.85 MPa) groups in the same material. Significance. Both resin-matrix ceramic materials seem up-and-coming restorative systems for occlusal veneers irrespective of the thicknesses as a consequence of the high reliability. (C) 2020 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved. (AU)

• FAPESP's process: 18/21317-6 - Material and thickness influence on reliability and internal and marginal adaptation of onlays produced by CAD/CAM technology
• Grantee: Mirelle Maria Ruggiero
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 12/19078-7 - Development and processing of Al2O3-ZrO2 translucent composite for CAD/CAM monolithic prostheses: the effect of aging on biaxial flexural strength
• Grantee: Estevam Augusto Bonfante
• Support Opportunities: Research Grants - Young Investigators Grants