Antimicrobial Efficacy of Sonic v/s Ultrasonic Activation on Disinfection of Root Canal System: An In Vitro Study

The key for long-term success in root canal therapy is the effective debridement with chemical irrigants before obturation. The purpose of this study was to compare the antimicrobial effect of sodium hypochlorite and chlorhexidine along with activation using sonic and an ultrasonic device in teeth when used in teeth infected with Enterococcus faecalis.

A total of 90 single rooted mandibular premolar were infected with E. faecalis and placed in the incubator for 24 hours .The specimens were divided into six groups as follows: Group I: positive control; Group II: negative control; Group III: sodium hypochlorite + passive ultrasonic activation for 20, 40, and 60 seconds; Group IV: chlorhexidine + passive ultrasonic activation; Group V: sodium hypochlorite + endoactivator; and Group VI: chlorhexidine + endoactivator activation. After disinfection, dentinal shavings were collected using H file and subcultured in brain heart infusion agar (BHI) broth further streaked in brain heart agar plates to check the colony counting.

Bonferroni post hoc test was done to compare the significant difference between different experimental groups. Group III showed a significant difference in the antimicrobial activity compared to Group IV, V, and VI with P <0.05. One-way analysis of variance (ANOVA) analysis was done to analyze the intergroup comparison of the bacterial count at various time intervals (20, 40, and 60 seconds). It was observed that there was a statistically significant difference with P <0.01 between the time interval of different experimental groups.

Within the limitation of this study, sodium hypochlorite along with passive ultrasonic irrigation showed a reduction in E. faecalis count compared to the other irrigating protocols used in the study and the results were statistically significant.