Effect of Different In-Office Bleaching techniques on Enamel Color and Surface Roughness: In Vitro Study

Objective: To evaluate and compare the influence of various in-office bleaching agents on enamel color change and surface roughness Materials and Methods: Sixty human permanent maxillary central incisors were collected and maintained in cylinder plastic mold (1cm height and 2cm width). Teeth were assigned based on the test into two groups; color change test group (n=30), and the surface roughness test group (n=30). Based on the bleaching technique, each group was further assigned into 3 subgroups (n=10) (light activated bleaching agent: Philips Zoom, chemical-activated; Philips Dash and two layer technique chemical activated; Zoom QuickPro). A spectrophotometer was used to measure the enamel color change in each bleaching technique. In addition, a non-contact optical profilometer was used to assess the surface roughness both before and after bleaching. The outcomes for each test were analyzed statistically using Student’s t-test, one-way analysis of variance (ANOVA) followed by post-hoc tukey. The level of significance was set at p ≤ 0.005. Results : Considering the color change measurements, all tested groups after bleaching exhibited statistical significant difference (P=0.0112). The Zoom group had the highest mean values subsequently Dash and Quick pro groups. For the surface roughness results, there was no statistical significant difference of all the tested groups after bleaching (P=0.592). Conclusions: All the studied in-office bleaching systems had a positive effect on teeth whitening; with the highest whitening potential for the light-activated system in comparison to the chemical-activated and two layer bleaching techniques. The enamel surface roughness exhibited insignificant changes in the different studied systems.