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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Implant-abutment fit influences the mechanical performance of single-crown prostheses

Texto completo
Autor(es):
Ramalho, Ilana S. [1] ; Bergamo, Edmara T. P. [1] ; Witek, Lukasz [2] ; Coelho, Paulo G. [2] ; Lopes, Adolfo C. O. [1] ; Bonfante, Estevam A. [1]
Número total de Autores: 6
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, Dept Prosthodont & Periodontol, Bauru Sch Dent, Bauru, SP - Brazil
[2] NYU, Dept Biomat & Biomimet, New York, NY - USA
Número total de Afiliações: 2
Tipo de documento: Artigo Científico
Fonte: JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS; v. 102, FEB 2020.
Citações Web of Science: 0
Resumo

Objectives: To evaluate the three-dimensional fit of abutments fabricated by the industry to those either milled or cast by a commercial laboratory and to correlate the implant-abutment connection fit with stress at fatigue failure of prostheses. Probability of survival (reliability) and fractography to characterize failure modes were also performed for cemented and screw-retained prostheses. Methods: One-hundred and twenty-six maxillary central incisor crowns were milled to restore implants and divided in 3 cemented and 3 screwed-retained groups (n = 21/each), as follows: {[}Digital-Sc]: milled one-piece monolithic abutment/crown; {[}TiB-Sc]: milled crowns cemented onto Ti-base abutments; {[}UCLA]: screwretained crown using UCLA abutments; {[}Digital-Ce]: milled two-piece assembly comprised by screwed monolithic abutment and a cemented crown; {[}TiB-Ce]: milled coping cemented onto Ti-base abutments to receive a cemented crown; {[}UCLA-Ce]: UCLA abutments that received an overcast coping and a cemented crown. Implant-abutment volume misfit was assessed by micro-computed tomography using the silicone replica technique. Implant/crown systems were subjected to stepstress accelerated life testing (SSALT) in water. The use-level probability Weibull curves and reliability for a mission of 50,000 cycles at calculated stress at failure of 2,300, 3300 and 4300 MPa were plotted. Fractographic analysis was performed with scanning electron microscopy. Internal misfit was analyzed through one-way ANOVA following post-hoc comparisons by Tukey test (p < 0.05). Correlation between misfit volume and the stress at fatigue failure was assessed by Pearson test. Results: Similar misfit volumes were observed for TiB-Sc (0.458 mm(3)), TiB-Ce (0.461 mm(3)), UCLA (0.471 mm(3)) and UCLA-Ce (0.480 mm(3)), which were significantly lower than Digital-Sc (0.676 mm(3)) and Digital-Ce (0.633 mm(3)). The mean beta values were: 1.68, 1.39, 1.48, 2.41, 2.27 and 0.71 for Digital-Sc, TiB-Sc, UCLA, Digital-Ce, TiB-Ce and UCLA-Ce, respectively, indicating that fatigue was an accelerating factor for failure of all groups. Higher stress at failure decreased the reliability of all groups, more significantly for screw compared to cement-retained groups, especially for Digital-Sc that demonstrated the lowest reliability. The failure mode was restricted to abutment screw fracture. A negative correlation was observed between misfit values and stress at failure (r = -0.302, p = 0.01). Conclusions: Abutments milled by a commercial lab presented higher misfit compared to those provided by the industry and a moderate correlation was observed between higher misfit and lower stress at failure during fatigue. Probability of survival decreased at higher stress, especially for screw compared to cement-retained groups, and failures were confined to abutment screws. (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
Linha de fomento: Auxílio à Pesquisa - Apoio a Jovens Pesquisadores
Processo FAPESP: 19/14798-0 - Desenvolvimento de blocos pré sinterizados de compósito ZTA - 80%Al2O3/20%ZrO2 para fresagem em sistema CAD/CAM
Beneficiário:Adolfo Coelho de Oliveira Lopes
Linha de fomento: Bolsas no Brasil - Doutorado
Processo FAPESP: 16/17793-1 - Desenvolvimento e caracterização mecânica e óptica de compósito 80% Al2O3 e 20% ZrO2 translúcida para próteses monolíticas CAD/CAM
Beneficiário:Adolfo Coelho de Oliveira Lopes
Linha de fomento: Bolsas no Brasil - Mestrado
Processo FAPESP: 19/08693-1 - Compósitos experimentais à base de alumina e zircônia infiltrados por vidro: caracterização microestrutural e das propriedades ópticas e mecânicas.
Beneficiário:Edmara Tatiely Pedroso Bergamo
Linha de fomento: Bolsas no Brasil - Pós-Doutorado
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
Linha de fomento: Auxílio à Pesquisa - Programa Equipamentos Multiusuários