Evaluation of the bond strenghts of the different generation adhesive systems to enamel after bleaching with diode laser

The increased interest in aesthetic dentistry requires aesthetic restorations and tooth whitening to be applied together. The aim of this in-vitro study is to evaluate effectiveness of diode laser whitening on the bond strength of composite restorations using different adhesive systems. One hundred eighty human maxillary incisor teeth were used in the study. After enamel surfaces were sanded and flattened, teeth were divided into 18 groups (n=10). Six groups which 3 different adhesive systems were applied without bleaching were the control groups. In half of the experimental groups, Opalescence Boost PF 40% in the other half LaserWhite 20 Bleaching Gel with 940nm wavelength diode laser were used for whitening. Following the bleaching process, three different adhesive systems (Adper Single Bond2, Clearfil SE Bond and Clearfil Universal) were applied with different waiting times (immediately and one week later) and after that teeth were restorated by composite resin. Specimens were put through shear bond strength test, then examined under a stereomicroscope to determine failure modes and one specimen from each group was evaluated with scanning electron microscope (SEM). One way variance analysis was used for comparison between groups. P values were considered statistically significant when calculated below 0. 05. According to the result, it was concluded that whitening agents negatively affected bonding and waiting a week after bleaching eliminates the decrease in bonding values. Whitening with diode laser might be an alternative option due to reasons such as short working time and no statistically significant difference when compared with Opalescence Boost. Keywords: Adhesive system, bond strength, diode laser, enamel, office bleaching