Impact of Adhesive Application Modes on Shear Bond Strength of Resin Composites to Biodentine

Purpose: This in-vitro study aimed to evaluate the impact of the adhesive application mode on the shear bond strength of various resin composites to Biodentine. Materials and Methods: A total of 60 acrylic blocks, each with a central hole (2 mm x 5 mm), were made for the study (n = 60). The holes were filled with Biodentine (Septodont), and the samples were randomly divided into three groups based on the type of restorative material used: 1) conventional posterior composite, Estelite Posterior Quick (EP)(Tokuyama); 2) bulk-fill composite, Filtek Bulk Fill (FB) (3M ESPE); and 3) short fiber-reinforced composite, EverX Posterior (EX)(GC). Additionally, each group was subdivided into two categories depending on the adhesive application method: self-etch or total-etch. A universal adhesive (Single Bond Universal, 3M ESPE) was applied to the Biodentine specimens, and subsequently, the resin composites were applied and light-cured for 20 s. The shear bond strength was measured using a universal testing machine (AGS-1000D, Shimadzu) at a crosshead speed of 1 mm/min. The shear bond strength data (MPa) were analyzed using a two-way ANOVA and the Bonferroni test (p < 0.05). Results: For the self-etch application mode, a statistically significant difference was observed among the material groups (p = 0.005). Group EP exhibited higher shear bond strength compared to Group FB. There were also significant differences among the groups for the total-etch application mode (p = 0.009), with Group EP again showing the highest shear bond strength. However, when comparing the two etching modes within each material group, there were no significant differences in shear bond strength. Conclusions: The conventional posterior composite used significantly affects the strength of the shear bond to Biodentine. In contrast, the choice between self-etch and total-etch modes does not notably impact the bond strength.