(PR069) Bacterial Debridement Efficacy of Two Sonic Root Canal Irrigant Activation Systems

Objective: To evaluate the bacterial debridement efficacy of two generations of sonic root canal irrigant activation systems: EndoActivator (first generation) and SmartLite Pro EndoActivator (second generation).

Methods: Instrumented, autoclaved, single-rooted human premolars were inoculated with Enterococcus faecalis for 21 days. The bacteria biofilm-containing teeth were randomly divided into 5 groups (n=8): Group 1: Syringe-side-vented needle (S-N) delivery of saline for 1 min; Group 2: S-N delivery of 2% NaOCl for 1 min; Group 3: S-N delivery of 2% NaOCl for 5 min; Group 4: EndoActivator activation of 2% NaOCl for 1 min; and Group 5: SmartLite Pro EndoActivator activation of 2% NaOCl for 1 min. The teeth were evaluated for bacterial reduction using CFU counts. The percentages of dead bacteria within dentinal tubules were determined using confocal laser scanning microscopy.

Results: Activation of NaOCl with EndoActivator or SmartLite Pro EndoActivator significantly reduced the overall intracanal bacterial load, compared with S-N irrigant delivery (p < 0.05). There was no significant difference between the 2 agitation devices (p>0.05). Nevertheless, S-N delivery of 2% NaOCl for 5 min produced better bacteria debridement than either sonic agitation system. Different degrees of bacterial kill were identified in the coronal-middle and apical portions of the canal space.

Conclusion: Delivery time of NaOCl affects the efficacy of bacterial disinfection. Activation with the EndoActivator or SmartLite Pro EndoActivator for 1 min demonstrated comparable canal wall biofilm and intracanal bacteria reduction efficacy when 2% NaOCl was used as irrigant for disinfection E. faecalis in single-rooted teeth.