Autor(es)

Ramos-Tonello, Carla Muller ; Trevizo, Bruno Freitas ; Rodrigues, Raphaela Farias ; Rodrigues Magalhaes, Ana Paula ; Furuse, Adilson Yoshio ; Lisboa-Filho, Paulo Noronha ; Tabata, Americo Sheitiro ; Sanches Borges, Ana Flavia

• Tipo de documento: Artigo Científico
• Fonte: Journal of Applied Oral Science; v. 25, n. 6, p. 8-pg., 2017-11-01.

Resumo

Sandblasting is a common method to try to improve the Y-TZP/veneer bond strength of dental prostheses, however, it may put stress on zirconia surfaces and could accelerate the t -> m phase transformation. Y-TZP sandblasting before sintering could be an alternative to improve surface roughness and bonding strength of veneering ceramic. Objectives. The aim of this study was to analyze the effect of Y-TZP pre-sintering sandblasting on surface roughness, phase transformation, and the Y-TZP/veneer shear bond strength. Material and Methods. The Y-TZP specimen surface underwent sandblasting with aluminum oxide (50 mu m) pre-sintering (Z-PRE) and post sintering (Z-POS). Z-CTR was not subjected to surface treatment. After ceramic veneer application, the specimens were subjected to shear bond testing. Surface roughness was analyzed by confocal microscopy. Y-TZP monoclinic and tetragonal phases were evaluated by micro-Raman spectroscopy. Shear bond strength and surface roughness data were analyzed by One-way ANOVA and Tukey tests (alpha=0.05). Differences in the wave numbers and the broadening bands of the Raman spectra were compared among groups. Results. Z-POS (9.73 +/- 5.36 MPa) and Z-PRE (7.94 +/- 2.52 MPa) showed the highest bond strength, significantly higher than that of Z-CTR (5.54 +/- 2.14 MPa). The Ra of Z-PRE (1.59 +/- 0.23 mu m) was much greater and significantly different from that of Z-CTR (0.29 +/- 0.05 mu m) and Z-POS (0.77 +/- 0.13 mu m). All groups showed bands typical of the tetragonal (T) and monoclinic (M) phases. Y-TZP sandblasting before sintering resulted in rougher surfaces but did not increase the shear bond strength compared to post-sintering and increased surface defects. Conclusions. Surface treatment with Al3O2, regardless of the moment and application, improves the results of Y-TZP/veneer bonding and is not a specific cause of t -> m transformation. (AU)

• Processo FAPESP: 11/18061-0 - Análise mecânica, estrutural e de copings de zircônia experimental para uso em sistema CAD/CAM
• Beneficiário: Ana Flávia Sanches Borges
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 13/23464-2 - Resistência de união entre Y-TZP/cerâmica de cobertura após tratamento de superfície
• Beneficiário: Bruno Freitas Trevizo
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica