RESUMO
OBJECTIVES: To investigate the effect of light-illuminating direction (from composite or enamel side) on color adjustment at the coronal and cervical enamel borders in composite restorations. MATERIALS AND METHODS: Forty cylindrical holes (3.0-mm diameters) were prepared in bovine enamel disks (1.0-mm thickness). After application of a one-step self-etch adhesive, one of four resin composites (Estelite Asteria, EA; Estelite Pro, EP; Kalore, KA; Clearfil Majesty ES-2 Premium, MJ) was restored in the holes. After 24-h storage, the colors (L*, C*, or h* values) at the restored enamel disks over a black background were measured in a black box using a CIE XYZ camera, spotted with D65 standard illuminant either from coronal or cervical side at 45°/0° geometry. The color shifting rate was calculated at the coronal and cervical enamel borders of the composite restorations, and analyzed by three-way ANOVA with Dunnett's T3 and t test for post hoc analysis (p < 0.05). RESULTS: The light-illuminating directions significantly affected the L* shifting rate at the cervical enamel border in EP and MJ (p < 0.05), and the C* shifting rate at the coronal enamel border in EA, EP, and MJ (p < 0.05). CONCLUSIONS: The color appearance at the border of the composite restoration was influenced by the light-illuminating direction in conjunction with the enamel rod orientation in the coronal or cervical enamel border. CLINICAL RELEVANCE: The line-of-vision angle would affect the perception of color adaptation at the enamel borders in the composite restorations.
Assuntos
Resinas Compostas , Restauração Dentária Permanente , Animais , Bovinos , Cor , Esmalte Dentário , Luz , Cimentos de ResinaRESUMO
This study aimed to investigate the influence of enamel prism orientations on color adjustment of resin composite restoration. The color measurements (L*, C*, or h* values) at the restored bovine enamel disk (1.0 mm-thick) with resin composite (Estelite Asteria, Estelite Pro, Kalore, Clearfil Majesty) were performed using a CIE XYZ camera (RC500). The color shifting rate and range at the coronal and cervical border were calculated. The coronal border was significantly lower L* and C* color shifting rate than the cervical border (p<0.05). The L* color shifting range was significantly affected by regions in the 3-mm cavity group (p<0.05), but not in the 1-mm cavity group (p>0.05), while the C* color shifting range was not significantly affected by regions (p>0.05). The coronal enamel border with diagonal-cut of enamel prisms would have an advantage for color adjustment of resin composite restorations compared to the cervical border with longitudinal-cut of enamel prisms.
Assuntos
Cor , Resinas Compostas/química , Esmalte Dentário/química , Restauração Dentária Permanente , Animais , Bovinos , Técnicas In Vitro , Metacrilatos , Propriedades de SuperfícieRESUMO
This study aimed to investigate the effect of enamel margin configuration on color change of resin composite restoration. Enamel disks of 1.0 mm-thick were sliced from sixty bovine anterior teeth and divided into three groups by margin configuration (non-bevel, 45-degree bevel and 45-degree reverse-bevel). The color measurements (L*C*h* values) at the restored bovine enamel disk with resin composite (Estelite Asteria, Estelite Pro, Kalore, Clearfil Majesty) were performed using a digital camera with CIE XYZ color gamut (RC500). All the resin composite restorations with non-beveled and beveled cavities significantly increased L* values compared with the control composite disks (p<0.05). The bevel preparation increased L* values toward the enamel-composite border with gentle inclination, while the reverse-bevel preparation was significantly lower L* values at the enamel-composite border than the non-bevel preparation (p<0.05). Enamel margin configuration affected color shifting of resin composite restoration and color adjustment of the border.