Fluoride-releasing adhesive and antimicrobial self-etching primer effects on shear bond strength of orthodontic brackets.

OBJECTIVE

To determine whether the combination of a new antimicrobial primer and a fluoride-releasing adhesive will affect the shear bond strength (SBS) and the bracket/adhesive failure mode.

MATERIALS AND METHODS

A total of 120 extracted human teeth were randomly divided into three groups of 40 specimens each (20 incisors, 20 premolars). Transbond XT was used in group 1, a fluoride-releasing adhesive (Kurasper F) was used in group 2, and a new antimicrobial self-etching primer (Clearfil Protect Bond) was applied in combination with Kurasper F in group 3. A universal testing machine was used to determine the SBS, and the adhesive remaining after debonding was assessed.

RESULTS

No enamel fractures were detected in any of the specimens. SBS values for incisors and premolars were 11.40 +/- 4.65 MPa and 10.37 +/- 3.36 MPa in group 1, 14.50 +/- 4.22 MPa and 13.06 +/- 5.13 MPa in group 2, and 14.79 +/- 4.10 MPa and 14.60 +/- 3.55 MPa in group 3. Statistically significant difference (P = .001) was found in the premolars in group 3 revealing the highest mean SBS. Significantly lower adhesive remnant index (ARI) values (median ARI value of 1) were detected in group 3 when compared with groups 1 and 2.

CONCLUSIONS

Considering the acceptable bond strength and the mode of failure, the combination of the new antimicrobial primer with the fluoride-releasing adhesive is recommended for clinical use.