INFLUENCE OF SURFACE RESIN COATING ON THE SUSCEPTIBILITY OF ACTUAL RESIN COMPOSITES TO BLEACHING.

Introduction: In-office bleaching usually affects resin composite restorations, however they may benefit from surface resin coatings. The present study assessed the influence of in-office bleaching on the color of resin composite surfaces polished using some recommended protocols. Materials and methods: Finished Filtek Z350, Ceram X, Tetric N-Ceram and Tetric N-Ceram bulk fill specimens were polished using surface resin coating and Sof-Lex discs before their intermitent exposure to the Opalescence Bosst PF for 60 min. Color change (ΔE) for each specimen was measured using CIE Lab system. Results and discussion: All resin composites showed comparable (P> 0.05), clinically acceptable color changes (ΔE= 1-3.3). However, only the resin coated, and the disc polished Tetric N-Ceram specimens showed higher (P<0.05), unacceptable color changes (ΔE> 3.3). Conclusions: No benefit of surface resin coating was noticed, so that replacement of the bleached Tetric N-Ceram restorations should be considered. [ABSTRACT FROM AUTHOR]