In vivo comparison of reduction in bacterial count after caries excavation with 3 different techniques

Abstract

Purpose: The purpose of this in vivo study was to evaluate and compare the reduction in bacterial count in dentin after caries excavation with a spoon excavator, carbide bur, and polymer bur.

Methods: Forty-five primary molar teeth from 36 children with occlusal dentinal carious lesions without pulpal involvement were chosen and divided into 3 groups: (1) caries was excavated using a brand new round bur with a slow-speed handpiece at 800 rpm from the occlusal aspect; (2) new polymer burs were used with slow-speed handpiece at 800 rpm, according to the lesion's size; (3) caries was excavated using a sterile spoon excavator.

Results: The mean difference in colony forming units of Streptococcus mutans and lactobacilli before and after caries excavation was found to be significant (P<.01) in all 3 groups. Further intergroup comparison of percentage reduction in bacterial counts between different groups was statistically significant, except when the percentage reduction in S mutans of group 2 was compared to that of group 3 (P=.26). Reduction in S mutans count was highly significant (P<.001) for group 1 vs group 3.

Conclusions: Caries removal with a carbide bur, polymer bur, and spoon excavator produced significant reduction in viable count of both Streptococcus mutans and lactobacilli. Carbide burs, however, produced greater reduction in the viable count of bacteria followed by polymer bur and spoon excavator.