Influence of convergence angle of tooth preparation on the fracture resistance of Y-TZP-based all-ceramic restorations

Autor(es)

Corazza, Pedro Henrique ^[1] ; Feitosa, Sabrina Alves ^[1] ; Souto Borges, Alexandre Luiz ^[1] ; Della Bona, Alvaro ^[2]

Afiliação do(s) autor(es)

^[1] Sao Paulo State Univ UNESP, Dept Dent Mat & Prosthodont, Sao Jose Dos Campos, SP - Brazil

^[2] Univ Passo Fundo, Sch Dent, Postgrad Program Dent, BR-99001970 Passo Fundo, RS - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Dental Materials; v. 29, n. 3, p. 339-347, MAR 2013.
• Citações Web of Science: 30

Resumo

Objective. To investigate the influence of the convergence angle of tooth preparation on the fracture load of Y-TZP-based ceramic (YZ - Vita YZ) substructure (SB) veneered with a feldspathic porcelain (VM9 - Vita VM9). Methods. Finite element stress analysis (FEA) was performed to examine the stress distribution of the system. Eighty YZ SB were fabricated using a CAD-CAM system and divided into four groups (n = 20), according to the total occlusal convergence (TOC) angle: G6 - 6 degrees. TOC; G12 - 12 degrees TOC; G20 - 20 degrees TOC; and G20MOD - 20 degrees TOC with modified SB. All SB were veneered with VM9, cemented in a fiber reinforced epoxy resin die, and loaded to failure. Half of the specimens from each group (n = 10) were cyclic fatigued (10(6) cycles) before testing. Failure analysis was performed to determine the fracture origin. Data were statistically analyzed using Anova and Tukey's tests (alpha = 0.05). Results. The greatest mean load to fracture value was found for the G20MOD, which was predicted by the FEA. Cyclic fatigue did not significantly affect the load of fracture. Catastrophic failure originating from the internal occlusal surface of the SB was the predominant failure mode, except for G20MOD. Significance. The YZ-VM9 restorations resisted greater compression load than the usual physiological occlusal load, regardless of the TOC angle of preparations. Yet, the G20MOD design produced the best performance among the experimental conditions evaluated. (c) 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 10/15009-5 - Influência da angulação do preparo coronário na resistência à fratura de restaurações cerâmicas à base de Y-TZP
• Beneficiário: Alvaro Della Bona
• Modalidade de apoio: Auxílio à Pesquisa - Regular