Effect of extrinsic pigmentation and surface treatments on biaxial flexure strength after cyclic loading of a translucent ZrO2 ceramic
Objective: To evaluate the influence of extrinsic pigmentation on the biaxial flexural strength and surface topographic of translucent Y-TZP (InCoris TZI – Sirona – USA) subjected to several surface treatments. Methods: Sintered zirconia discs-shaped specimens (n = 120) (ø:12 mm; thickness:1.2 mm; I...
| Autores: | , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2019 |
| País: | Brasil |
| Institución: | Universidade Estadual Paulista (UNESP) |
| Repositorio: | Repositório Institucional da UNESP |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.unesp.br:11449/197963 |
| Acceso en línea: | http://dx.doi.org/10.1016/j.dental.2019.08.117 http://hdl.handle.net/11449/197963 |
| Access Level: | acceso abierto |
| Palabra clave: | Biaxial flexural strength Phase transformation Surface characterization Zirconia surface treatment |
| Sumario: | Objective: To evaluate the influence of extrinsic pigmentation on the biaxial flexural strength and surface topographic of translucent Y-TZP (InCoris TZI – Sirona – USA) subjected to several surface treatments. Methods: Sintered zirconia discs-shaped specimens (n = 120) (ø:12 mm; thickness:1.2 mm; ISO 6872) were prepared and divided (n = 15) according to various factors: “extrinsic pigmentation” (n: without; p: with) and “surface treatments” (C: control — as sintered; A: abraded with silica-coated alumina particles (30 μm); G: glazed with a thin film of low-fusing porcelain glaze; GH: glazed and etched with 10% hydrofluoridric acid for 60 s. Mechanical cycling (1.2 × 106 cycles, 200 N, 3.8 Hz) and flexural strength test (1 mm/min — 1000 kg cell) were performed. Two-way ANOVA and Tukey's were used for statistical test (α = 0.05). Weibull analysis was used to evaluate the strength reliability. Samples were analyzed via (1) an optical profilometer to determine the surface roughness (Ra); (2) an X-ray diffraction (XRD) to evaluate phase transformations; and (3) a SEM equipped with an energy dispersive X-ray spectroscopy (EDX) to elucidate morphological properties and chemical compositions. Results: Regardless of the surface treatment (p = 0.5459) (Cn: 560.16 MPa; Gn: 573.36 MPa; An: 643.51 MPa; GHn: 542.94 MPa; Cp: 628.04 MPa; Gp: 641.90 MPa; Ap: 554.47 MPa; GHp :602.84 MPa) and extrinsic pigmentation (p = 0.1280) there was no difference in the flexural strength among the experimental groups. According to the XRD analysis, phase transformations occurred in the An group (t → m) and in Ap group (t → c). Surface roughness was affected by surface treatments (An — p = 0.001) and extrinsic pigmentation (Gp — p = 0.001). Significance: The biaxial flexural strength of the tested samples was not affected neither by surface treatments nor by pigmentation, although it can cause phase transformation and promote surface roughness. |
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