The effect of home and office bleaching on the microleakage after Class V composite resin restoration

Abstract

Introduction: The bleaching is actually brightening the tooth color, which is done in two ways at home and in the office. The use of bleaching may have detrimental effects on tooth restoration. The aim of this study was to investigate the effect of at-home and in-Office bleaching system on the microleakage of Class V composite resin restorations, Which are performed using different generations of adhesive.(5th generation, 6th generation, 7th generation, 8th generation in both SE and ER systems)

Materials and methods: Class V cavities prepared on the buccal surfaces of 180 caries free anterior teeth. Then, the teeth were randomly divided into 5 groups based on the adhesive systems (n=36) consisting of: 5th, 6th, 7th generations and 8th generation in both SE and ER systems. Cavities were restored with composite and finished and polished completely. Then they were left for 24 hours in distilled water at 37˚ C. Then each group was divided into three subgroups (n=12): control subgroup (without bleaching), bleached subgroup by in-office bleaching method, and bleached subgroup by at-home bleaching method. In the second subgroup, each tooth was exposed to a at home whitening agent for 8 hours a day for 10 consecutive days, and in the third subgroup, each restoration was exposed to a chemically active whitening agent for 40 minutes. After bleaching, all the teeth were thoroughly washed and dried, then the samples wewe covered with nail polish, in a way that a space of 1 mm remained around the margin of the cavity on each tooth. The teeth were then submerged in a 0.5% solution of fuchsine at 37˚ C for 24 hours. Then the samples were washed using water and each sample was cut longtudinally with a low-speed diamond disk with water cooling and then evaluated for microleakage in enamel and dentin margins using stereomicroscope with 40x magnification. For data analysis, Ordinal regression was used. A probability value less than 0.05 was considered a significant level.

Results: Based on the results obtained from ranking regression, test adhesive type and margin type had a significant effect on the amount of microleakage (P-value<0.05). So that the amount of microleakage in Adper single bond, Clearfil SE bond and Clearfil S3 bond adhesives was significantly higher than single bond universal (ER). The Enamel margin had less microleakage than the cervical margin. The intervention or the bleaching method had no significant effect on the amount of microleakage (P-value> 0.05).

Conclusions: Based on the results of microleakage test, a significant difference was observed between different adhesive systems, and the amount of microleakage in the cervical margin was higher than the enamel margin. Bleaching after adhesive systems had no significant effect on the microleakage of class V restorations.

Key words: teeth bleaching’ Microleakage’ composite resin restorations’ adhesive systems