Assessment of Effect of Flowable Composite on the Shear Bond Strength of Sapphire Bracket Bonded to Composite Restoration: An in Vitro Study

Introduction: We aimed to assess the effect of flowable composite on shear bond strength (SBS) of sapphire bracket bonded to composite restoration. Methods: Forty composite discs (3M Filtek Z250) were allocated into four groups: control group (C) conventional primer (Transbond XT) with conventional composite (Transbond XT adhesive paste) was used, group (F1): conventional bonding agent, group (F2): universal bonding agent (Scotchbond) and group (F3): all surface bonding agent (Assure plus) were used with bulk fill flowable composite (3M Filtek), then sapphire brackets were bonded to the composite discs. After bonding, the specimens were thermocycled for 5000 cycles, SBS was measured, and the adhesive remnant index (ARI) was determined. Results: One-way analysis of variance and the post-hoc Tukey's test demonstrated significant differences between conventional and flowable composite. Kruskal-Wallis test found that there was no significant difference in ARI between the study groups. Conclusion: Flowable composite groups had significantly lower SBS than the control group.