Residual stress of porcelain-fused to zirconia 3-unit fixed dental prostheses measured by nanoindentation

Autor(es)

Fardin, Vinicius P. ^{[1, 2]} ; Bonfante, Estevam A. ^[1] ; Coelho, Paulo G. ^{[3, 4]} ; Janal, Malvin N. ^[5] ; Tovar, Nick ^[3] ; Witek, Lukasz ^[3] ; Bordin, Dimorvan ^[6] ; Bonfante, Gerson ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Bauru Sch Dent, Dept Prosthodont & Periodontol, Bauru, SP - Brazil

^[2] Univ Vila Velha, Dept Prosthodont, Vila Velha, ES - 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, Coll Dent, Dept Epidemiol & Hlth Promot, New York, NY - USA

^[6] Univ Guarulhos, Dept Operat Dent, Guarulhos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Dental Materials; v. 34, n. 2, p. 260-271, FEB 2018.
• Citações Web of Science: 4

Resumo

Objective. To evaluate the residual stress (nanoindentation based on hardness) of fatigued porcelain-fused to zirconia 3-unit fixed dental prostheses (FDP) with different framework designs. Methods. Twenty maxillary 3-unit FDP replacing second-premolar (pontic) were fabricated with conventional framework-design (even-thickness of 0.5 mm and 9 mm(2) connector area) and modified framework-design (thickness of 0.5 mm presenting lingual collar connected to proximal struts and 12 mm2 connector area). Connector marginal ridges were loaded and the fractured and suspended FDPs were divided (n = 3/each) into: (1) Fractured zirconia even-thickness (ZrEvenF); (2) Suspended zirconia even-thickness (ZrEvenS); (3) Fractured zirconia with modified framework (ZrModF); (4) Suspended zirconia with modified framework (ZrModS); (5) Non-fatigued FDP with conventional framework design (Control). The FDPs were nanoindented at 0.03 mm (Region of Interest (ROI) 1), 0.35 mm (ROI 2) and 1.05 mm (ROI 3) distances from porcelain veneer outer surface with peak load 4000 mu N. The Linear Mixed Analysis of Variance (ANOVA) Model on ranks and Least Significant Difference Test on ranks (95%) were used. Results. Highest rank hardness values were found for Control group and ZrModS, whereas the lowest values were found in ZrModF. Statistical differences (p = 0.000) were found among all groups except for comparison between ZrModS and Control group (p = 0.371). Hardness between ROIs were statistically significant different (p < 0.001) where ROI 1 presented the lowest values. Significance. Framework-design modification did not influence the residual stress of porcelain-fused to zirconia fatigued 3-unit FDP. Whereas fractured FDPs showed the highest residual stress compared to suspended and control FDPs. Residual stress increased as nanoindented away from framework. (C) 2017 The Academy of Dental Materials. Published by Elsevier Ltd. 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
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• Linha de fomento: Bolsas no Brasil - Mestrado
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• Beneficiário: Vinicius Pavesi Fardin
• Linha de fomento: Bolsas no Brasil - Doutorado