Influence of convergence angle of tooth preparation on the fracture resistance of Y-TZP-based all-ceramic restorations
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Data
2013-03-01
Autores
Corazza, Pedro Henrique [UNESP]
Feitosa, Sabrina Alves [UNESP]
Borges, Alexandre Luiz Souto [UNESP]
Bona, Alvaro Della
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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° TOC; G12-12° TOC; G20-20° TOC; and G20MOD-20° 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 (106 cycles) before testing. Failure analysis was performed to determine the fracture origin. Data were statistically analyzed using Anova and Tukey's tests (α = 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. © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.
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Palavras-chave
CAD-CAM, Ceramics, Failure analysis, Finite element analysis, Tooth preparation, All-ceramic, CAD-CAM systems, Catastrophic failures, Compression loads, Convergence angle, Cyclic fatigue, Experimental conditions, Fiber reinforced epoxy resins, Finite element stress analysis, Four-group, Fracture load, Fracture origins, Occlusal surfaces, Tooth preparations, Cams, Ceramic materials, Epoxy resins, Finite element method, Restoration, Stress analysis, Stress concentration, Veneers, Yttrium alloys, Fracture, Computer Programing, Failure, Finite Element Analysis, Polyepoxides, Stress Concentration, Tooth
Como citar
Dental Materials, v. 29, n. 3, p. 339-347, 2013.