Comparison of Shear Bond Strength of Orthodontic Brackets on Provisional Crowns Using Two Distinct Bonding Agents: An In Vitro Study

Objectives To evaluate and compare the shear bond strength (SBS) of orthodontic brackets by employing a conventional composite bonding agent and an alternative self-cure acrylic resin for bonding orthodontic attachments to three different provisional crown materials. Methods A total of 42 material specimens were prepared: 14 discs, each made of provisional crown materials, namely, bis-acryl composite, self-cure acrylic resin, and heat-cure acrylic resin. These 14 discs of each provisional crown material were randomly allocated into two groups: the first group of 7 was bonded using the conventional bonding technique, and the other group of 7 was bonded with self-cure acrylic resin as the bonding agent. SBS was measured using a Hounsfield universal testing machine, and the Adhesive Remnant Index (ARI) was evaluated. A post hoc power analysis was performed to validate the statistical findings. Results One-way analysis of variance revealed significant differences ( P < .001). Self-cure acrylic resin demonstrated the highest mean SBS when bonded to self-cure acrylic crowns (13.48 MPa). The lowest SBS was observed in heat-cure acrylic crowns bonded with composite resin (6.14 MPa). Conclusion Bonding brackets to self-cure acrylic provisional crowns using self-cure acrylic resin results in the highest SBS. While all groups met clinically acceptable thresholds, the alternative self-cure protocol provided superior bond strength compared to the conventional method across all tested materials.