An in vitro evaluation of shear bond strength of chemical and light-cured bonding materials with stainless steel, ceramic, and sapphire brackets

Abstract EN

Background : This study was intended to compare shear bond strength of chemical and light-cured bonding materials with stainless steel, ceramic, and sapphire brackets, and to measure adhesive remnant index after debonding.

Materials and method : Sixty non-carious, free of cracks upper first premolar teeth, which have been extracted from 18-25 years old Iraqi patients seeking orthodontic treatment were selected.

Three types of orthodontic brackets were used in this study : stainless-steel, ceramic, and sapphire brackets.

All bracket types used were of standard edgewise system.

The teeth were divided into two groups of 30 teeth each.

One group was used for testing the chemically cured primer-activated resin of no-mix type, while the other was used for testing of the light-cured resin.

The chemically and light-cured groups were further subdivided according to bracket type into three groups of 10 teeth each.

The samples were tested for bond strength using an Instron universal testing machine, while for adhesive remnant index the enamel surface and bracket base of each tooth were inspected under magnifying lens (20X) of a stereomicroscope.

Results : The highest shear bond strength values were found in sapphire brackets followed by stainless steel and ceramic brackets respectively, both in no-mix and light-cured groups as revealed by ANOVA test.

T-test showed that the shear strength values were higher for all light-cured groups as compared to no-mix groups.

Conclusions : Sapphire brackets have the highest shear bond strength as compared to stainless-steel and ceramic brackets.

Light-cured resin has better bonding properties than no-mix resin.