Zirconia-reinforced lithium silicate crowns: Effect of thickness on survival and failure mode

Autor(es)

Bergamo, Edmara T. P. ^[1] ; Bordin, Dimoruan ^[2] ; Ramalho, Ilana S. ^[3] ; Lopes, Adolfo C. O. ^[3] ; Gomes, Rafael S. ^[1] ; Kaizer, Marina ^{[4, 5]} ; Witek, Lulzasz ^[4] ; Bonfante, Esteuam A. ^[3] ; Coelho, Paulo G. ^{[4, 6, 7]} ; Del Bel Cury, Altair A. ^[1]

Afiliação do(s) autor(es)

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

^[2] Universus Veritas UNG, Dept Restorat Dent, Guarulhos, SP - Brazil

^[3] Univ Sao Paulo, Dept Prosthodont & Periodontol, Bauru Sch Dent, Bauru, SP - Brazil

^[4] NYU, Coll Dent, Dept Biomat & Biomimet, New York, NY - USA

^[5] Positivo Univ, Grad Program Dent, Curitiba, Parana - Brazil

^[6] NYU Langone Hlth, Sch Med, Hansjorg Wyss Dept Plast Surg, New York, NY - USA

^[7] NYU, Mech & Aerosp Engn, Tandon Sch Engn, New York, NY - USA

• Tipo de documento: Artigo Científico
• Fonte: Dental Materials; v. 35, n. 7, p. 1007-1016, JUL 2019.
• Citações Web of Science: 0

Resumo

Objective. To evaluate the reliability and failure mode of zirconia-reinforced lithium silicate (ZLS) molar crowns of different thicknesses. Methods. Monolithic ZLS molar crowns (0.5 mm, 1.0 mm, and 1.5 mm thickness) were modeled and milled using a CAD/CAM system (n = 21/group). Crowns were cemented on dentin-like epoxy resin replicas with a resin cement. The specimens were subjected to single load-to-failure test for step-stress profiles designing. Mouth-motion step-stress accelerated-life test was performed under water by sliding an indenter 0.7 mm lingually down on the distobuccal cusp until specimen fracture or suspension. Use level probability Weibull curves and reliability were calculated and plotted. Polarized-light optical microscope and scanning electron microscope (SEM) were used to characterize fracture patterns. Results. Irrespective of crown thickness, beta (beta) values were higher than 1 and fatigue accelerated failures. While 0.5 mm ZLS crowns exhibited a significant reduction in the probability of survival at 200 N, 300 N and 400 N mission loads (69%, 41% and 19%, respectively), no significant difference was observed between 1.0 mm and 1.5 mm crowns. Both thicknesses have maintained the survivability at approximately 90%. Failure primarily comprised bulk fracture where radial cracks originated from the cementation surface beneath the indenter loading trail and propagated towards the cervical margin. Significance. 1.5 mm- and 1.0 mm-thickness monolithic ZLS crowns presented higher probability of survival compared to 0.5 mm crowns. Bulk fracture was the chief failure mode, regardless of thickness. (C) 2019 Published by Elsevier Inc. on behalf of The Academy of Dental Materials. (AU)

• Processo FAPESP: 12/19078-7 - Desenvolvimento e processamento de compósito de Al2O3-ZrO2 para próteses monolíticas CAD/CAM: efeito do envelhecimento na resistência à flexão biaxial
• Beneficiário: Estevam Augusto Bonfante
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 16/18818-8 - EMU concedido no processo 2012/19078-7: ElectroPuls E3000 Linear-Torsion All-Electric dynamic test instrument package
• Beneficiário: Estevam Augusto Bonfante
• Modalidade de apoio: Auxílio à Pesquisa - Programa Equipamentos Multiusuários