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The aim of this study was to investigate the effectiveness of diode laser‐assisted bleaching on the shear bond strength (SBS) of different adhesive systems to enamel and examine the adhesive enamel interface under scanning electron microscope (SEM). 180 incisor teeth were randomly divided into three bleaching groups: (1) Unbleached control group, (2) Opalescence Boost (OB) 40%, and (3) Diode laser‐assisted LaserWhite20 (LW20) 45%. After bleaching, each group was divided into two subgroups according to waiting time: immediately or 7 days' delay. The six groups were then divided into three subgroups based on the adhesive procedure: Single Bond 2 (SB2), Clearfil SE Bond (CSB), and Clearfil Universal Bond (CUB). After adhesive procedures, composite resin cylinders were bonded to the enamel surfaces. All specimens were subjected to a SBS test after 24 hr of storage in water. Data were analysed using three‐way variance analysis (p < .05). Specimens were examined under a stereomicroscope and SEM. There was a significant difference between the groups bonded immediately and 7 days after bleaching (p < .05). SB2 after 7 days showed the highest SBS values (19.24 ± 2.18), whereas CUB showed the lowest values in both bleaching treatments and control groups (10.84 ± 1.66). SEM analysis of the unbleached specimens revealed long tags and uniform hybrid layer compared OB and LW20 bleaching groups. LW20 and OB bleaching adversely affected SBS to enamel when bonded immediately. Diode laser‐assisted bleaching might be an alternative option due to the short working time but delaying bonding for 7 days after bleaching may not be enough for ideal adhesion. Research Highlights Bleaching agents containing high concentration hydrogen peroxide reduces the enamel bond strength of adhesive systems. Postponing composite restorations for 7 days after bleaching may not be sufficient to achieve ideal adhesion. Diode laser‐assisted bleaching may be preferred as an alternative bleaching method today due to its ability to shorten the operation time and cause minimal morphological changes on the enamel surface.

Background: This study was designed to determine the effects of various finishing and polishing systems on the surface roughness and color stability of a glass carbomer filling material containing fluorapatite/hydroxyapatite particles. Materials and Methods: A glass carbomer filling material (with and without protecting coat [gloss] n = 100) and a microhybrid resin-based composite (n = 50) were tested in the study. No finishing and polishing was applied to ten samples for each material. The remaining samples were finished and polished with OneGloss, Enhance/PoGo, Identoflex, and Sof-Lex discs, and stored in a coffee solution. Surface roughness assessments were made with a profilometer. Color measures (L* a* b*) were calculated with a colorimeter on the periods of different staining procedures. For the data analysis, two-way analysis of variance was employed. For multiple comparisons, Bonferroni adjustment was used (P < 0.05). Results: The lowest and highest Ra values were found in the group of microhybrid resin-based composite with Mylar strip (0.17 ± 0.04, P < 0.05) and in the group of glass carbomer with gloss with Mylar strip (1.17 ± 0.30, P < 0.05), respectively. The ΔE* and ΔL* values of the glass carbomer with gloss were higher than the other groups. The microhybrid resin-based composite showed less change in all parameters. Conclusion: The results showed that the glass carbomer did not provide a high level of color stability and surface roughness like the microhybrid resin-based composite. On the other hand, the glass carbomer material was affected negatively by the gloss application.