Avaliação da translucidez de diferentes cerâmicas odontológicas utilizadas para restaurações monolíticas

• Autor(a) principal: Carneiro, Cristina Marçal Araujo
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório do Centro Universitário Braz Cubas
• Texto Completo: https://repositorio.cruzeirodosul.edu.br/handle/123456789/2082
• topic: Odontologia clínica; Ligas metalo-cerêmicas; Meios de contraste; Restauração dentária permanente; CNPQ::CIENCIAS DA SAUDE::ODONTOLOGIA

The objective of this study was to evaluate the translucency of different dental ceramic systems for monolithic restorations (lithium disilicate glass ceramic, zirconiareinforced lithium silicate glass ceramic, feldspathic ceramic and translucent zirconia), in two thicknesses, using different parameters (contrast ratio, translucency parameter, quantitative analysis of irradiance and percentagem of light attenuation). Slices of ceramic blocks with thickness 1 mm or 2 mm of different dental ceramics (n = 6) were prepared: lithium disilicate glass ceramic (IPS e.max Press), zirconia-reinforced lithium silicate glass ceramic (Suprinity), feldspathic ceramic (VitaBlocks Mark II) and translucent zirconia (Zirkonzahn Prettau). A spectrophotometer (Spectro Shade Micro) was used to measure the CIELab coordinates and the reflectance value (Y) of specimens placed on white and black backgrounds. The translucency parameter (TP) and the contrast ratio (CR) were calculated. All readings were done in triplicate. The quantitative analysis of the irradiance was performed using images obtained from the ceramic blocks coupled to a light emitting source (LED curing unit with 870 mW/cm2 ). The data were analyzed by two-way ANOVA (ceramic and thickness) and Tukey’s test with a significance level of 5%. The correlation between CR, TP and percentage of light attenuation was determined by the Pearson correlation coefficient. CR ranged from 0.64 (SL, 1 mm) to 0.96 (ZT, 2 mm). TP values ranged from 3.68 (ZT, 2 mm) to 32.19 (SL, 1 mm). The irradiance and percentage of light attenuation varied, respectively, from 138.70 mW/cm2 (ZT, 2 mm) to 404.45 mW/cm2 (SL, 1 mm), and from 53.51% (SL, 1 mm) to 84.06% (ZT, 2 mm). There was a strong negative correlation between CR and TP (R = -0.9967), a strong negative correlation between TP and light attenuation percentage (R = -0.8820) and a strong positive correlation between CR and light attenuation percentage (R = 0.9032). It can be concluded that the ceramic systems and the thicknesses influenced the translucency parameters evaluated. For all parameters, the zirconia-reinforced lithium silicate glass ceramic presented the highest degree of translucency, while the translucent zirconia showed the lowest translucency. For all materials studies, the higher the thickness, the higher the CR value, the higher the light attenuation percentage and the lower the TP value.