Shear bond strengths of a selenium containing and a conventional light cured adhesive for orthodontic bonding

The objectives of this study were to evaluate the debonding strength and mode of failure of a selenium containing adhesive compared to an established orthodontic adhesive.

One hundred sixty bovine mandibular incisors were allocated to eight groups: steel and clear brackets were bonded with either selenium containing adhesive (Group 1: SeLect Defense) or a conventional light-cured adhesive (Group 2:Transbond XT) to measure debond strength and the adhesive remnant index was used to assess the location of bond failure. Data was evaluated using a three-way analysis of variance and Fisher's PLSD multiple comparisons test for mean debond strengths.

Group 2 debond strengths were greater than that of Group 1 with the steel and clear brackets. Group 1 debond strengths were greater with clear than with steel brackets at both time points. Both adhesives demonstrated increased debond strengths from zero to 24 hours and the clear brackets exhibited a greater ARI than steel after debonding. Comparisons of debond strength means among adhesives, brackets, and times were all statistically significant.

All debond strengths were within a clinically acceptable range according to previous literature. SeLect Defense may be desirable due to its potential for preventing white spot lesions despite the reduced strength compared to Transbond XT.