Adhesion of Metal Brackets to Longitudinal E-glass Fibers

Objectives:The objectives of this study were: 1- to evaluate the bond strength of brackets to enamel and glass fiber and 2- to determine the failure after debonding the brackets and evaluate the damage to the enamel and the fibers. Methods: 60 intact, caries-free mandibular incisors were embedded in polyethylene (PVC) cylinders. The teeth were randomly assigned to 6 groups and subjected to different surface treatments. Group 1 (n=10) The control group. Brackets were bonded in the conventional way. Enamel surface was etched and bonding agent was applied. Brackets were bonded with adhesive and light cured. Group 2 (n=10) Brackets were bonded to the fiber on the enamel and light cured. Group 3 (n=10) Fiber bonded to enamel and light cured received resin monomer prior to bracket bonding. Group 4 (n=10) Silica coated, silanized brackets were bonded in the conventional way to enamel. Prior to bonding, brackets received a sandblasting surface pre-treatment method with 30 mic SiOx CoJet®- sand particles and the application of silane coupling agent. Group 5 (n=10) Silica coated, silanized brackets were bonded to the fiber on the enamel and light cured. Group 6 (n=10) Fiber bonded to enamel and light cured received resin monomer and the brackets were silica coated, silanized prior to bonding. Shear bond strength values of the groups were compared by a one-way analysis of variance (ANOVA) (P< 0.05). Debonding characteristics were analyzed using an ARI score and Failure location score.Results: Bracket conditioning resulted in significantly higher SBS (18.5 ± 6.4 MPa) when compared to non-conditioning (as received brackets) (10.3 ± 2.6 MPa) (p<0.05). Conclusions: The use of fiber-glass in combination with orthodontic metal brackets resulted in lower bond strength values compared to non-fiber control groups.