Masking ability of composite resin and feldspathic porcelain with and without opaquer application for severe tooth discoloration

Objective: This study compared the ability of composite resin and feldspathic porcelain to mask tooth discoloration at different thicknesses, with and without opaquer application.Methods: In this in vitro study, composite resin (VOCO Grandio) and feldspathic porcelain (Noritake Super Porcelain EX-۳) specimens (n=۲۰ per material) were prepared in shade A۲ at thicknesses of ۰.۵ and ۱.۰ mm (n=۱۰ per thickness) and placed over a C۴-shade porcelain substrate that simulated a severely discolored tooth. Each specimen was evaluated with and without opaquer application (composite resin opaquer or opaque resin cement, depending on the material). Color was measured according to the CIE Lab* system, and the color difference (ΔE) was calculated between each specimen under the test condition and the intrinsic reference color of the material. Data were analyzed using three-way ANOVA, with the significance set at P<۰.۰۵.Results: The porcelain group showed lower ΔE values than the composite resin group at both thicknesses, with and without opaquer application. The three-way ANOVA revealed that thickness, opaquer application, and material type each had a significant effect on ΔE (P<۰.۰۰۱). The thickness–opaquer interaction was also significant (P=۰.۰۴). At ۰.۵ mm thickness, both opaquer application and material type significantly influenced ΔE (P<۰.۰۰۱), whereas at ۱.۰ mm, the effect of neither factor was significant (P=۰.۷۸ and P=۰.۸۳, respectively). Conclusions: At a conservative restoration thickness of ۰.۵ mm, enhanced masking performance was achieved by using feldspathic porcelain instead of composite resin and by applying an opaquer. However, clinically acceptable masking of severe discoloration was not achieved.

کلیدواژه ها:

color ، Composite Resin ، dental porcelain ، Dental Veneers ، esthetics ، Tooth discoloration