Comparison of shear bond strength and residual adhesive remnants on the enamel surface after debonding of three different orthodontic molar tubes : A scanning electron microscope study.

Background: The aim for this research was to evaluate and compare the impact, bond strength, and residual adhesive on the enamel surface after debonding of different orthodontic molar tubes. The tested materials were metal, composite, and newly introduced ceramic orthodontic molar tubes.

Materials and methods: In all, 66 first molar teeth were randomly divided into three groups. Metal, glass-fiber composite and ceramic orthodontic molar tubes were bonded and shear bond strength (SBS) tests were performed. The adhesive remnant index (ARI) scores after debonding were recorded and the enamel surfaces were investigated using scanning electron microscopy (SEM) after the adhesives were cleaned.

Results: The mean SBS values of the metal and ceramic tube groups were significantly higher than that of the glass-fiber composite tube group. The highest SBS values were recorded for the ceramic tube group (11.09 ± 2.51 MPa). Failure typically occurred at the adhesive-enamel interface in the ceramic group, whereas the majority of the samples in the glass-fiber composite group showed failure at the adhesive-tube base interface according to ARI and SEM investigations. ARI 1 and ARI 2 scores were commonly observed for the metal tube group.

Conclusions: All the molar tubes tested had generated clinically acceptable SBS values; however, the values for glass-fiber composite molar tubes were significantly lower than those for the ceramic and metal molar tubes. If the debonding procedure is performed carefully, the ceramic molar tubes may be an enamel-safe product for patients seeking fully esthetic orthodontic treatment.