Early and Delayed Effect of Cavity Disinfection with Chlorhexidine and Ozone on the Shear Bond Strength of Dentin to Glass Hybrid Restoration: An In Vitro Study

We aimed to evaluate the early and delayed effects of chlorhexidine (CHX) and ozone disinfection on the shear bond strength (SBS) of dentin to glass hybrid restoration.

The occlusal surfaces of 60 extracted premolars were trimmed to obtain a flat dentinal surface and randomly divided into three groups, including distilled water (control), 2% CHX, and ozonized water. Each group was further subjected to a shear bond strength test after 24 hours and 3 months.

The overall model test (P < 0.001), disinfectant and time (P < 0.001), and time (P=0.017) showed statistically significant differences among study groups. Yet, the type of disinfectant revealed a non-significant difference (P= 0.238). Post hoc tests showed SBS significantly decreasing over time in the control group (P < 0.001) while the difference between 24 hours and 3 months for the CHX (P= 0.880) and ozone (P=0.983) groups was not significant.

Within the inherent limitations of in vitro studies, it can be concluded that cavity disinfection with CHX and ozone before glass hybrid restoration had a significant effect on the stability of SBS to dentin over 3 months. The type of disinfectant revealed non-significant difference.