Cultivatable Bacteria in Deep Carious Lesion after Ozone Disinfection

Objectives: The study was aimed to investigate local effect of gaseous ozone on cultivatable bacteria in deep carious lesions after incomplete caries removal, using chlorhexidine as control.

Methods: Forty-eight posterior teeth with deep caries lesions, but without signs and symptoms of irreversible pulpitis, were submitted to incomplete caries removal. The teeth were randomly allocated into two groups regarding the cavity disinfectant used: ozone or 2% chlorhexidine. Dentin samples obtained before and after cavity disinfection were microbiologically investigated for the total aerobic and anaerobic bacteria, and Streptococcus spp. The treatment effect was assessed by pair-t test and independent t test.

Results: Significant decrease in number of aerobic and anaerobic bacteria, and Streptococcus spp. was observed after cavity disinfection with either ozone or chlorhexidine (p<0.01). Comparing reduction between two disinfectants, a significant greater reduction by chlorhexidine was seen for Streptococcus spp. (p<0.01) but not aerobic and anaerobic number (p>0.05).

Conclusions: Ozone might serve as a suitable cavity disinfectant in inhibiting the residual bacteria in deep caries lesions after incomplete caries removal.