In vitro mechanical properties assessment of newly developed orthodontic self-adhesive resins

Abstract

Objectives

This study aimed to develop novel self-adhesive resins for orthodontic bracket bonding that can provide clinically acceptable bond strengths, leave minimal remnant adhesive and enamel damage upon bracket debonding.

Materials and methods

A plain self-adhesive resin was used as a control, from which three main modified self-adhesive resin groups were developed for bracket bonding: bioactive glass, strontium fluoride and grape seed extract. All groups were subjected to three artificial aging models prior to shear bond strength, adhesive remnant index, enamel damage index and micro-hardness assessments.

Results

All groups yielded clinically acceptable shear bond strength values. The addition of 0.5 % grape seed extract to plain self-adhesive resin+1 % bioactive glass yielded the highest shear bond strength, minimal adhesive remnant index and minimal enamel damage post debonding, yet the differences were statistically insignificant (p > 0.05). The best performance regarding microhardness was displayed by the addition of 0.5 % grape seed extract.

Conclusions

The formulation (1 % bioactive glass+ 0.5 % grape seed extract) yielded clinically satisfactory shear bond strength, minimal adhesive residue, minimal enamel damage, and highest micro-hardness mean value as compared to the control and other experimental self-adhesive resin groups.