Evaluation and comparision of the shear bond strength of rebonded orthodontic brackets with air abrasion, flaming, and grinding techniques: an in vitro study.

Aim: To evaluate and compare in vitro the shear bond strength of rebonded orthodontic brackets among the three most frequently used rebonding methods--sandblasting, direct flaming, and grinding with a green stone bur. The surface characteristics of new and rebonded bracket bases were also compared using scanning electron microscopy (SEM).

Methods: The sample used in the present study comprised 60 extracted human premolars bonded with brackets. The sample was divided into three groups (each n = 20; sandblasting, direct flaming, and grinding with a green stone bur). SEM was used to compare the surface characteristics of the new and rebonded bracket bases for all three groups.

Results: The Z test for the direct flaming and grinding groups revealed statistically significant bond strength (P < .05). The ANOVA test for all three groups showed P < .05, which is statistically significant. SEM for the sandblasting method showed well-defined retentive areas.

Conclusion: When rebonding brackets, sandblasting the bracket base yields the highest bond strength.