Effect of remineralizing agents on resin-dentin bond durability of adhesive restorations: An in vitro study

Aim: To prolong the clinical success and durability of bonded restorations, hybrid layer stabilization is crucial for better adhesion between the resin and tooth substrate. The aim of this in vitro study was to assess the ability of self-assembling peptide (curodont protect) and a remineralizing agent (MI paste plus) in promoting biomimetic remineralization for stabilization of the hybrid layer to improve the resin-dentin bond durability. Materials and Methods: Standardized mesio-occlusal (MO) and disto-occlusal (DO) cavities were prepared on 60 mandibular molars. Teeth were randomly allocated to different groups and after acid etching, half of the MO cavities (n = 30) of dentin were treated with curodont protect and another half (n = 30) with MI paste plus. Half of the DO cavities (n = 30) were pretreated with chlorhexidine, whereas the other half did not receive any dentin pretreatment before placing adhesive restoration. Half of the samples from each group (n = 15) were subjected to thermomechanical load cycles. Immediate and after aging bond strengths were estimated using a universal testing machine, and the type of bond failure was assessed under a scanning electron microscope. Data obtained in megapascals were analyzed by one-way analysis of variance and Tukey’s multiple post hoc test with the significance level set as P ≤ 0.05. Results: Immediate bond strength values were significantly high for the control group and low for the MI paste plus group (P = 0.002). Significant differences were not observed between the curodont protect and chlorhexidine (P = 0.0514) treated groups. In all groups, bond strength values were decreased significantly after thermomechanical cyclic (TMC) loading (P = 0.0001). Adhesive type fractures were reported more in failure mode analysis. Conclusion: All groups exhibited reduced microtensile bond strength values after aging. The dentin treated with chlorhexidine, curodont protect, and MI paste plus produced more durable bonding than the control group.