Abstract
Objective: To evaluate the influence of color saturation on the degree of conversion (DC) of nanohybrid composite resins. Methods: Ten specimens of a nanohybrid composite resin (5 mm x 5 mm) with different color saturations (A1, A2, A3 and A3.5) were obtained and sectioned longitudinally. One half of each specimen was polished and was stored at 37 °C for 24 hours. For DC determination, readings were performed at depths of 0.01 (top), 1, 2 and 4 millimeters, with a micro-Raman spectrophotometer. Statistical procedures were performed with Two-way ANOVA and Holm-Sidak method. Statistical significance was set at p<0.05. Results: Degree of conversion values were not affected by the depth of polymerization up to 2 mm, independent of the color saturation of the composite resin (p> 0.05). All groups showed a significantly lower DC at depth of 4 mm when compared to the other depths (p <0.05). At the depth of 4 mm, A3.5 group presented a lower DC between groups (p <0.05). Conclusion: Color saturation of nanohybrid composite resins does not interfere in polymerization up to 2 mm deep. However, the saturated colors, such as A3.5, at 4 mm depth cause reduction in DC.