Optical properties stability of light-cured versus pre-cured CAD-CAM composites

Abstract

The aim of this study was to evaluate the optical properties changes after staining of pre-cured (PC) and light-cured (LC) composites. Specimens were prepared using different LC composites (GrandioSO - Voco, Filtek Z350 - 3M/ESPE, Opallis - FGM and Kalore - GC) and four PC composites (Grandio Blocs - Voco, Lava Ultimate - 3M ESPE, Brava Block - FGM and Cerasmart - GC) (n=20). Baseline color, gloss, translucency, and fluorescence were evaluated. Staining protocol was performed for 15 days and the final optical properties were reevaluated. The changes on each property were calculate (Delta Gloss, Delta Trauslucency, Delta Fluorescency, Deltamathbf{E}{*}00). Data were analyzed by ANOVA and Tukey's test (alpha=5%). Changes on all properties were observed after staining for all materials, with darkening and reduction of gloss, fluorescence and translucency. Non-significant differences were observed between the light-cured and pre-cured materials of the same manufacturer for the Deltamathrm{G} and Deltamathbf{T}, but significant differences existed for Delta mathbf{F} and Deltamathbf{E}{*}00). For Delta mathbf{F}, the only significant differences were observed between Brava Block and Opallis (smaller). For Delta mathbf{E}{*}{}_{00}, only the light-cured composites GrandioSO and Z350 showed significant less change than the corresponding blocks. Pre-cured composites were affected the same way than light-cured ones by the staining in relation to the reduction of gloss and translucency. A higher reduction of fluorescence was observed only for one brand of block and was similar for the others. Two brands the light-cured materials showed less staining, while for the others was similar. The effects of staining vary according to the composite formulation.