Effect of Chlorhexidine and Ozone Gel on Microleakage and Shear Bond Strength of Dentin Bonding Agents in Composite Resin Restorations of Primary Teeth

Aim: This study aimed to investigate the effects of two antimicrobial agents on shear bond strength and microleakage of composite resin restorations in primary teeth. Methods: Sixty extracted primary molars and canines were assigned to three different groups according to the dentin surface pretreatment (2% chlorhexidine gluconate gel, ozone gel, and control group) and two subgroups (sound and caries-affected dentin) for shear bond strength tests. For the microleakage test process, a class V cavity was prepared on the buccal surface of the teeth and restored with composite resin. Then, all the teeth were cut buccolingually. The depth of stain penetration in each specimen was measured separately according to the scale. The data have been analyzed using SPSS 24 software. Results: In both sound and caries-affected dentin, ozone gel exhibited higher shear bond strength than chlorhexidine gel and the control group (P < 0.001). Chlorhexidine gel had no significant effect on the shear bond strength of sound dentin (P=0.561), but it reduced it in the caries-affected dentin (P < 0.001). With both disinfectants, the shear bond strength of the caries-affected dentin was significantly lower than that of the sound dentin. The application of chlorhexidine gel to caries-affected dentin resulted in more microleakage than sound dentin. In addition, the amount of microleakage in the ozone gel group was similar in both types of dentin. Conclusion: In both sound and caries-affected dentin, ozone gel was associated with higher shear bond strength than chlorhexidine gel; furthermore, chlorhexidine increased microleakage and ozone gel decreased it.