Does the use of glycerin gel improve the color stability of composite resins?

Abstract Introduction The resin composite superficial layer not polymerized due to the presence of oxygen leads to clinical problems as color alteration by the absorption of pigments. Objective Evaluate the effect of different techniques to control the formation of the composite resin dispersion layer on the optical properties of a commercial composite. Material and method Resin composite Estelite Sigma specimens were made. The specimens were light-cured with the LED Bluephase G2 device (1200 mW/cm2 - 40 s). The groups were determined according to three different techniques: 1) no treatment (control); 2) light-curing through a glycerin gel layer on the surface; 3) polishing with abrasive discs after light-curing. The color stability (ΔE) and the translucency parameter were determined by the spectroscopy method (Easyshade Compact Vita) as a function of the CIELab parameter. The analyzes were performed immediately after photoactivation and repeated after 7 days of storage in water or 7 days in coffee. The results were submitted to ANOVA and Tukey test (α = 0.05). Result No difference was found for ΔE in groups aged in water. When stored in coffee, the control group had the highest value of ΔE while the polished group generated the lowest color change. The glycerin gel groups promoted intermediated results. The translucency parameter was not affected by the treatments tested. Conclusion: The glycerin-based gel layer minimizes the color change in those regions that the finishing and polishing instruments are difficult to access.