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Objective This trial evaluated the influence of polishing on enamel color change after in-office bleaching treatment. In addition, it evaluated the influence of polishing on tooth morphology and sensitivity. Materials and methods Fifty volunteers were randomized into two groups (n = 25): In-office bleaching with 35% hydrogen peroxide gel for 45 min without polishing (GSEM) or with polishing (GP). The color analysis was performed four times, at baseline, and immediately after the 1st, 2nd, and 3rd session of bleaching with Easyshade spectrophotometer (Vita-Zahnfabrik), using the CIELAB (ΔE) and CIEDE2000 (ΔE00) formulas, and whiteness index (ΔWID). A qualitative analysis of enamel morphology was performed using replicas obtained with epoxy resin observed in a scanning electron microscope (277× and 554× magnification). The tooth sensitivity was assessed daily using the visual analog scale (α = 0.05). Results There was no statistically significant difference (p > 0.05) in tooth color change when comparing ΔE, ΔE00, and ΔWID between groups. The enamel surface showed greater areas of irregularities and depressions in the GP group than in the GSEM group. There was no difference in tooth sensitivity (p > 0.05) between groups. Conclusions Polishing after in-office tooth whitening does not change the tooth color and sensitivity and promotes greater changes in enamel surface morphology. Clinical relevance: Polishing immediately after tooth whitening causes greater changes in enamel surface morphology.

The aim of this in vitro study was to assess the bond strength of self-etching adhesives containing HEMA and 10-MDP monomers. Twenty-four bovine teeth were divided into three groups. Two cylinders of composite resin were made in each tooth (n = 16): G1-Prime and Bond Universal (control); G2-OptiBond All-in-One (HEMA); and G3-Clearfil SE (10-MDP and HEMA). After 24-hour storage in distilled water, the specimens were fixed to a universal testing machine (Kratos Equipamentos Ltda.) for the microshear test at a speed of 0.5 mm/min. A qualitative analysis of the fracture pattern was also performed using scanning electron microscopy (500× magnification). The normality of sample data distribution was determined using the Shapiro–Wilk test. The results were assessed using the Kruskal–Wallis test, and α level of 5% was used for the analysis. The results indicated a statistical difference ( p > 0.05 ) between G3 (15.6080 MPa) and G2 (11.2180 MPa). No statistical difference was observed when G1 (14,6325 MPa) was compared with the other two groups. It was also observed that a mixed fracture pattern was predominant in all groups. The self-etching adhesive containing HEMA and 10-MDP monomers showed to be promising in increasing the bond strength between the dental substrate and the composite resin, whereas the adhesive containing only HEMA exhibited lower bond strength to dentin.