The effect of different bracket base cleaning method on shear bond strength of rebonded brackets.

Aim: To assess the effect of different bracket base conditioning method on shear bond strength (SBS) of rebonded brackets.

Materials And Methods: Eighty brackets were bonded to freshly extracted premolar teeth using light cured composite adhesive. SBS was measured for 20 random samples as control group (G1). After debonding, 60 debonded brackets were allocated randomly into three groups of bracket base conditioning methods to remove the remaining adhesives. G2: bracket base cleaned with slow speed round carbide bur (CB), G3: cleaned with ultrasonic scaler (US), G4: cleaned with sandblasting (SB). After that, brackets were rebonded in the same manner as frst bonding and SBS was measured. Modifed adhesive remnant index (ARI) was recorded for all groups.

Results: SBS for new brackets was 11.95 MPa followed by 11.65 MPa for G2, 11.56 MPa for G4 and 11.04 MPa for G3 group. There were no statistically signifcant differences between all groups (p = 0.946). In all groups, failure mode showed that the majority of adhesive composite remained on the bracket base with ARI of 4. There was no statistically signifcant difference between all groups in ARI (p = 0.584).

Conclusion: In-offce methods; slow speed CB and US are effective, quick and cheap methods for bracket base cleaning for rebonding.