Lifetime prediction of veneered versus monolithic lithium disilicate crowns loaded on marginal ridges

Autor(es)

de Paula, Vitor Guarconi ^[1] ; Bonfante, Gerson ^[1] ; Lorenzoni, Fabio C. ^[2] ; Coelho, Paulo G. ^{[3, 4, 5]} ; Bonjardim, Leonardo Rigoldi ^[6] ; Fardin, Vinicius P. ^[7] ; Bonfante, Estevam A. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Bauru Sch Dent, Dept Prosthodont & Periodontol, Alameda Otavio Pinheiro Brisola 9-75, BR-17012901 Bauru, SP - Brazil

^[2] Unigran Univ, Dept Prosthodont, Sch Dent, Dourados, MS - Brazil

^[3] NYU, Dept Biomat & Biomimet, New York, NY - USA

^[4] NYU, Langone Med Ctr, Hansjorg Wyss Dept Plast Surg, New York, NY - USA

^[5] NYU, Tandon Sch Engn, Mech & Aerosp Engn, New York, NY - USA

^[6] Univ Sao Paulo, Bauru Sch Dent, Dept Biol Sci, Bauru, SP - Brazil

^[7] Univ Vila Velha, Dept Prosthodont, Vila Velha, ES - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Dental Materials; v. 35, n. 3, p. 511-522, MAR 2019.
• Citações Web of Science: 1

Resumo

Objective. To evaluate the probability of survival of monolithic and porcelain veneered lithium disilicate crowns comprised by a conventional or modified core when loaded on marginal ridges. Methods. Lithium disilicate molar crowns (n = 30) were fabricated to be tested at mesial and distal marginal ridges and were divided as follows: (1) bilayered crowns with even-thickness 0.5 mm framework (Bi-EV); (2) bilayered crowns with modified core design (Bi-M-lingual collar connected to proximal struts), and: (3) monolithic crowns (MON). After adhesively cemented onto composite-resin prepared replicas, mesial and distal marginal ridges of each crown (n = 20) were individually cyclic loaded in water (30-300 N) with a ceramic indenter at 2 Hz until fracture. The 2-parameter Weibull was used to calculate the probability of survival (reliability) (90% 2-sided confidence bounds) at 1, 2, and 3 million cycles and mean life. Results. The reliability at 1 and 2 million cycles was significantly higher for MON (47% and 19%) compared to Bi-EV (20% and 4%) and Bi-M (17% and 2%). No statistical difference was found between bilayered groups. Only the MON group presented crown survival (7%) at 3 million cycles. The mean life was highest for MON (1.73E + 06), lowest for Bi-M (573,384) and intermediate for Bi-E (619,774). Fractographic analysis showed that the fracture originated at the occlusal surface. The highest reliability was found for MON crowns. The modified framework design did not improve the fatigue life of crowns. Significance. Monolithic lithium disilicate crowns presented higher probability of survival and mean life than bilayered crowns with modified framework design when loaded at marginal ridges. (C) 2019 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved. (AU)

• 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
• 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