Effect of Antimicrobial Pre-Treatment on the Microleakage and Shear Bond Strength of a Self- Adhesive Composite Hybrid Restorative Material: An in vitro Study

Objective: This study aimed to evaluate the effect of three types of cavity pretreatment disinfectants on the microleakage and shear bond strength (SBS) of the self-adhesive composite hybrid restorative material Surefil One. Methods: Sixty-four sound premolar teeth were utilized for conducting microleakage and shear bond strength experiments, with 32 teeth allocated to each test. The microleakage test was conducted on class V restorations on the buccal surfaces using the dye penetration method after pretreating the cavities before restoration. The SBS test was performed by putting a cylinder of the restoration on the dentin surface, subjected to pretreatment and then subjected to force by a universal testing machine. Each test consisted of 4 groups (n=8): group 1 (control group restoration without pretreatment of the surfaces), group 2 (chlorhexidine “CHX” group) pretreated with 2% chlorhexidine, group 3 (SDF group) pretreated with silver diamine fluoride and group 4 (NaOCl group) pretreated with 1% sodium hypochlorite. Results: No statistically significant differences (p>0.05) between the degree of microleakage and the type of disinfectant were detected in either enamel or cementum. In contrast, SBS showed significant differences between groups. The SDF group showed the highest SBS value, followed by the CHX group. However, for the NaOCl group, the SBS was negatively influenced, and the SBS was much lower than that of the control group. Conclusions: Antimicrobial pretreatment of dental cavities may have different effects on the adhesive properties (microleakage and shear bond strength) of the restorative dental material (self-adhesive hybrid restorative material) ranging from harmful to beneficial effects. None of the applied antimicrobial agents showed a significant effect on the microleakage values, while they showed different significant effects on the SBS values. Although sodium hypochlorite is a potent antimicrobial agent, it is not recommended for disinfecting restoration cavities since it has a negative effect on the SBS values. In contrast, Chlorhexidine solutions and silver diamine fluoride can be safely applied, with the added advantage of increasing the adhesive property of the Surefil One restorative material