cad a22 4500 390147915 20200627060550.0 cr unu---uuuuu 161201e201612 xx s 000 0 eng 10.5167/uzh-128016 doi 10.11607/prd.2524 doi (ZORA)oai:www.zora.uzh.ch:128016 610 ddc 27740655 pmid Fracture Strength, Failure Types, and Weibull Characteristics of Three-Unit Zirconia Fixed Dental Prostheses After Cyclic Loading: Effects of Veneering and Air-Abrasion Protocols [Elektronische Daten] [Fernanda Campos, Rodrigo O A Souza, Marco A Bottino, Mutlu Özcan] restrictedAccess eu-repo The required connector dimension for zirconia fixed dental prostheses (FDPs) may be a clinical limitation due to limited space in the occlusogingival direction. Using no veneering in the gingival regions of the pontics and connectors may solve this problem. This study evaluated the mechanical durability of zirconia FDPs with and without veneering in the gingival area of the connectors and pontics and subsequent air abrasion of this region with different protocols. Models were made of resin abutments (diameter = 6 or 8 mm, height = 6 mm, 6 degrees convergence) and embedded in polyurethane resin (distance = 11 mm). Zirconia frameworks were milled and randomly distributed by veneering (veneering of the entire framework [VEN] or no veneering at gingival regions of the pontic and connector [NVEN]) and by air-abrasion (Al₂O₃/SiO₂, 30 μm; or 45 μm Al₂O₃. FDPs were adhesively cemented and subjected to mechanical cycling (1,200,000 cycles, 200 N, 4 Hz, with water cooling). Specimens were tested until fracture (1 mm/min), and failure modes were classified. Data (N) were subjected to one-way analysis of variance in two sets, Tukey test (α = .05) and Weibull analysis. While veneering did not significantly affect the results (VEN: 1,958 ± 299 N; NVEN: 1,788 ± 152 N; P = .094), air abrasion did (P = .006), with the worst results for the groups conditioned with 45 μm Al₂O₃ (SiO₂: 1,748 ± 273 N; Al₂O₃: 1,512 ± 174 N). The NVEN group demonstrated the highest Weibull modulus (12.8) compared with the other groups (5.3-7.2). Fractures commonly initiated from the gingival side of the connector. Veneering of the gingival region of the connectors and pontics in zirconia FDPs did not diminish the fracture strength, but air-abrasion of this area with 45 μm Al₂O₃ decreased the results. Clinic of Reconstructive Dentistry zora Campos Fernanda joint author Souza Rodrigo O A. joint author Bottino Marco A. joint author Özcan Mutlu joint author International Journal of Periodontics and Restorative Dentistry 36(6):901-908 https://www.zora.uzh.ch/id/eprint/128016/1/Fracture%20Strength%2C%20Failure%20Types%20and%20Weibull%20Characteristics_acc.pdf text/html WWW-Backlink auf das Repository BK010053 XK010053 XK010000 1 Journal Article PeerReviewed zora ZORA ZORA ZORA Journal Article restrictedAccess ZORA 856 40 https://www.zora.uzh.ch/id/eprint/128016/1/Fracture%20Strength%2C%20Failure%20Types%20and%20Weibull%20Characteristics_acc.pdf text/html WWW-Backlink auf das Repository ZORA 700 1- Campos Fernanda joint author ZORA 700 1- Souza Rodrigo O A. joint author ZORA 700 1- Bottino Marco A. joint author ZORA 700 1- Özcan Mutlu joint author ZORA 773 0- International Journal of Periodontics and Restorative Dentistry 36(6):901-908