Tensile bond strength of metal bracket bonding to glazed ceramic surfaces with different surface conditionings

Abstract

Objective: The objective of this study was to compare the tensile bond strength
of metal brackets bonding to glazed ceramic surfaces using three various surface
treatments.
Materials and Methods: Forty two glazed ceramic disks were assigned to three
groups. In the first and second groups the specimens were etched with 9.5% hydrofluoric
acid (HFA). Subsequently in first group, ceramic primer and adhesive
were applied, but in second group a bonding agent alone was used. In third group,
specimens were treated with 35% phosphoric acid followed by ceramic primer
and adhesive application. Brackets were bonded with light cure composites. The
specimens were stored in distilled water in the room temperature for 24 hours and
thermocycled 500 times between 5°C and 55°C. The universal testing machine
was used to test the tensile bond strength and the adhesive remenant index scores
between three groups was evaluated. The data were subjected to one-way
ANOVA, Tukey and Kruskal-Wallis tests respectively.
Results: The tensile bond strength was 3.69±0.52 MPa forfirst group, 2.69±0.91
MPa for second group and 3.60±0.41 MPa for third group. Group II specimens
showed tensile strength values significantly different from other groups (P<0.01).
Conclusion: In spite of limitations in laboratory studies it may be concluded that
in application of Scotch bond multipurpose plus adhesive, phosphoric acid can be
used instead of HFA for bonding brackets to the glazed ceramic restorations with
enough tensile bond strength.