Proper timing of bonding composite resin to bleached enamel

Abstract EN

Studies have shown that bleaching treatment of enamel tooth surface interferes with bonding and adhesion of composite resin placed immediately after bleaching.

The aim of this study was to evaluate the influence of bleaching agent on micro shear bond strength of composite resin to bleached enamel after different intervals of time (control, immediate, one week) using two different based adhesive system of bonding (single bonding and self etch adhesive ).

Sixty human molar teeth were assigned into six groups (n=10) according to time elapsed between bleaching and bonding and type of bonding used.

Group 1: Control group, no bleaching treatment – composite resin bonded using single bond.

Group 2: Bleached 38% Hydrogen peroxide – composite resin bonded immediately after bleaching using single bond.

Group 3: Bleached 38% Hydrogen peroxide – composite resin bonded one week using single bond.

Group 4: No bleaching – control group composite bonded using self etch adhesive system.

Group 5: Bleached 38% Hydrogen peroxide – composite resin bond immediately after bleaching using self etch adhesive system.

Group 6: Bleached 38% Hydrogen peroxide – composite bonded using self etch one week later.

The micro shear bond strength test was performed using Nexygen MT Lloyd instrument at across head of 0.5 mm/min.

The data in MPA were subjected to analysis of variance ANOVA and Tukey’s test as significant difference at P<0.05 – data showed that control group without bleaching using both single bond and self etch adhesive system in bonding composite resin to enamel attained statistically significant highest micro shear bond strength followed by one week group while group bonded immediately after bleaching using self etchant adhesive showed the lowest bond strength.

The micro shear bond strength value of composite resin to bleached enamel is time and adhesive system dependant, seven days delay in bonding procedure for composite resin post bleaching to enamel is recommended.