# Effect of at-home and in-office bleaching on microleakage of class V composite resin restorations using different types of universal adhesives: An in vitro study

## TL;DR

This study found that bleaching after dental restorations does not significantly increase microleakage, but adhesive type and application method matter.

## Contribution

The study evaluates the impact of bleaching on microleakage using different universal adhesives and application modes.

## Key findings

- All Bond Universal adhesive showed higher microleakage compared to G-Premio Bond adhesive.
- Self-etch mode had nearly twice the chance of microleakage compared to etch-and-rinse mode.
- Bleaching method (at-home or in-office) did not significantly affect microleakage.

## Abstract

When bleaching agents contact dental structures, they act on restorative materials and adhesive interfaces. This study investigated the effect of "at-home" and "in-office" bleaching on the microleakage of composite resin restorations performed with different universal adhesives in self-etch and etch-and-rinse modes.

Class V cavities were prepared in 132 premolars. The samples were divided into four groups (n=33). All Bond Universal adhesive was used in the first and second groups, and G-Premio Bond adhesive was used in the third and fourth groups. The total-etch mode was used in the first and third groups, and the self-etch mode was used in the second and fourth groups. The samples were divided into three subgroups (n=11). In the first subgroup, home bleaching was used, and in the second subgroup, office bleaching was used. In the third subgroup, bleaching was not performed. The specimens were examined under a stereomicroscope for microleakage. Ordinal regression analysis was applied (P<0.05).

The adhesive type, application method, and margin type significantly affected microleakage (P<0.05). The amount of microleakage in All Bond Universal adhesive was significantly higher than in G-Premio Bond adhesive. The chance of microleakage in the self-etch mode was almost twice as high as in the etch-and-rinse mode. The bleaching method did not significantly affect microleakage (P>0.05).

Based on the results of the microleakage test, bleaching after composite resin restorations did not significantly affect the microleakage of Class V restorations.