RESUMO
INTRODUCTION: In this study, we compared the shear bond strengths of five different adhesive techniques for attaching metal orthodontic brackets onto acrylic pontics. MATERIALS AND METHODS: Two hundred upper left lateral incisor acrylic teeth with bonded brackets were divided into five groups - composite alone (control), composite following sandblasting, composite held with a mechanical undercut, cyanoacrylate adhesive and Panavia(®). The initial bond strength was tested using the Instron Universal Testing Machine. The fatigue bond strength was tested by subjecting each bracket to 5000 repetitive low-load cycles at 50% of the mean shear bond strength using the Dartec machine at 2âHz. RESULTS: Cyanoacrylate adhesive statistically exhibited the highest mean bond strength (19·82âMPa). This was followed by the mechanical undercut group (17·69âMPa) and the sandblasted group (17·18âMPa). There was no statistically significant difference when considering the effect of fatiguing (p = 0·238) as well as the interaction between the adhesive technique and the effect of fatiguing on the bond strength (p = 0·440). CONCLUSION: The initial and fatigue bond strengths of the cyanoacrylate adhesive, sandblasted and undercut groups were significantly higher than the control and Panavia(®) groups when tested under laboratory conditions.