Comparative Evaluation of the Effect of Different Types of Bleaching Dentifrices on Shear Bond Strength of Orthodontic Metal Brackets Bonded by Conventional Composite to Human Teeth: An In Vitro Study

TL;DR

This study compares how bleaching toothpastes affect the strength of orthodontic brackets on human teeth.

Contribution

The study empirically compares the effects of two types of bleaching dentifrices on bracket bond strength for the first time.

Findings

Bleaching dentifrices significantly reduced the shear bond strength of orthodontic brackets.

There was no significant difference between peroxide and active oxygen bleaching dentifrices in affecting bond strength.

Untreated teeth showed higher bond strength compared to bleached teeth.

Abstract

Aim: This study aims to evaluate and compare the effect of different types of bleaching dentifrices on the shear bond strength of orthodontic metal brackets bonded by light-cured composite adhesive to human teeth.

Materials and methods: Forty-five human premolar teeth were randomly divided into three groups, receiving the following treatments: Group 1 (control group; teeth in this group were not bleached), Group 2 (teeth in this group were treated with active oxygen bleaching dentifrice), and Group 3 (teeth in this group were treated with peroxide bleaching dentifrice). Orthodontic brackets were bonded using a light-cured composite adhesive. A universal measuring device was used to assess the shear bond strength with a crosshead speed of 0.5 mm/min. One-way ANOVA, post hoc Tukey tests, and an independent t-test were used to analyse the data.

Results: There was a highly significant difference (p≤0.001) in the mean shear bond strength of orthodontic brackets bonded to untreated teeth as compared to teeth treated with bleaching dentifrice. There was no significant difference in the mean shear bond strength of orthodontic brackets bonded to teeth treated with peroxide bleaching dentifrice or active oxygen bleaching dentifrice.

Conclusion: There was a significant reduction in the mean shear bond strength of orthodontic metal brackets when bonded to human teeth treated with bleaching dentifrices.

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