Efficacy Evaluation of a Cordless Ultrasonic Unit in Achieving Reduction of Bacterial Load Within a Root Canal System As Compared to a Conventional Ultrasonic Unit and Negative Pressure Irrigation

Introduction Increase in efficacy during root canal irrigation may contribute to better treatment outcomes. This study investigated the efficacy of ultrasonic and negative pressure irrigation systems using sodium hypochlorite (NaOCl) in the reduction of bacterial load in human teeth. One hundred thirty-one single-rooted teeth were cleaned and shaped, autoclaved, and incubated with E. faecalis . Teeth were randomly assigned to three experimental groups ( n = 40) and treated in the presence of 1% sodium hypochlorite using EndoUltra cordless ultrasonic, conventional ultrasonic, and Endovac negative pressure irrigation. Syringe irrigation controls were treated with 1% sodium hypochlorite and phosphate-buffered saline via side-vented needle irrigation. All groups with NaOCl received 5% sodium thiosulfate neutralization for 5 min after treatment. Samples of root canal fluid and dentin chips were acquired from canals before and after treatment, incubated on BHI agar, and colony forming units categorized according to quantity. Wilcoxon rank-sum and Bonferroni tests were used for statistical analysis. p values less than 0.05 were considered significant. Results Endovac group was significantly better in eliminating bacteria from the root canals than 1% NaOCl ( p = 0.006) and PBS syringe irrigation ( p = 0.015). However, it was not significantly different from the two ultrasonic groups ( p > 0.05). Both ultrasonic groups showed better performance than 1% NaOCl and PBS syringe irrigation, however, not statistically significant ( p < 0.03). There was no significant difference between the two ultrasonic devices ( p > 0.05). Conclusion EndoVac may be an important tool for bacterial load reduction in oval canals.