Effects of sandblasting and silica coating on the bond strength of rebonded mechanically retentive ceramic brackets


TOROĞLU M. S., Yaylali S.

AMERICAN JOURNAL OF ORTHODONTICS AND DENTOFACIAL ORTHOPEDICS, cilt.134, sa.2, 2008 (SCI-Expanded) identifier identifier identifier

Özet

Introduction: The aim of this study was to determine the bond strength of rebonded mechanically retentive ceramic brackets after treatment with 2 abrasive techniques. Methods: In addition to a group of new brackets, 3 groups were treated according to the following conditions of debonded ceramic bracket bases: sandblasting, sandblasting + silane, and silica coating + silane (15 in each group). Treated ceramic brackets were rebonded on premolars. The samples were stored in distilled deionized water for 24 hours at 37 C in an incubator and then thermocycled for 1000 times between 5 C and 55 C. Shear force was applied to the enamel- adhesive interface until debonding. Results: The highest bond strength values were in the silica coating + silane and the new bracket groups (12.7 and 12.0 MPa, respectively), followed by the sandblasting + silane group (10.5 MPa). The sandblasting group had a significantly lower bond strength value (4.5 MPa). No enamel fracture was noted in any sample tested. In the new bracket and the sandblasting + silane groups, 20% of the samples had adhesive remnant index scores of 2, and 80% had scores of 3. In the sandblasting group, all specimens debonded at the bracket-adhesive interface. The silica coating + silane group showed mixed failures. Conclusions: Sandblasting + silane and silica coating + silane applications on debonded ceramic bracket base can produce bond strengths comparable with new brackets.