Surface alterations of tooth colored restoratives after bleaching

Objective: The aim of this study was to evaluate the effect of two bleaching agents on the surface texture of six different tooth colored restoratives. Material and Method: From each of the following restoratives 51 polished (p) and 51 unpolished (u) specimens were prepared: a hybrid, a flowable, a microfilled, and a nanofilled composite resin as well as an ormocer and a ceramic. 21 polished and 21 unpolished samples from every material were bleached with a home-bleaching product (Opalescence® 15%). 30 polished and 30 unpolished surfaces from every material were treated with an in-office bleaching product (Opalescence® Xtra® Boost™). In the home-bleaching group 6 specimens (3p, 3u) served as negative control (no bleaching). Each 18 specimens were bleached 8h and 56h respectively. Each 6 of them (3p, 3u) were evaluated directly, 24h and 1 month after the bleaching procedure. In the in-office group 6 specimens served as neg. control. Each 18 specimen were bleached 15, 30 and 45 min respectively. Each 6 (3p, 3u) were evaluated directly, 24h and 1 month after the bleaching procedure. Surface texture was examined by SEM (magnification x200, x2000). Results: SEM pictures of the polished specimens did not exhibit any changes during the bleaching cycle or during the post-bleaching period. Neglectable changes occurred during the active bleaching period when treating the unpolished specimens with the in-office product. During the post-bleaching period these alterations did not progress with time. Specimens treated with the home bleaching product appeared to be similar to the control group during each stage of the study. Conclusions: Within the limits of this study, it can be concluded that the tested bleaching products did not alter surface texture of tooth colored restorations.