(PO140) Does the Root Canal Preparation Size Influence the Microbial Reduction by Gentlewave?

Abstract: This study aims to assess the efficacy of the GentleWave (GW) system against Enterococcus faecalis biofilm in small, medium, and large canal models in comparison with ultrasonic activation (PUI). Disto-buccal roots of maxillary molars, single-canal mandibular premolars, and palatal roots of maxillary first molars were instrumented to sizes 20/.04, 30/.04, and 50/.04, respectively, and autoclaved. Canals were then incubated with E. faecalis for 21 days. Teeth were randomly divided into two groups (15 teeth/group) and disinfected with either PUI or GW. Bacterial reduction from the root canals was calculated based on pre- and post-disinfection samples. Five teeth were selected randomly from each group and sectioned at the coronal, middle, and apical thirds, stained using live/dead bacteria stain, and analyzed using confocal laser scanning microscopy (CLSM). All S2 samples showed significant bacterial reduction compared to S1 (p < .05). Quantitative analysis demonstrated a bacterial reduction in PUI and GW of 99.2% and 97.8% in canals prepared to size 20/.04; 99.9% and 99.9% in canals prepared to size 30/.04; and 99.1% and 99.4% in the canals prepared to size 50/.04. CLSM demonstrated various bacterial penetration capabilities among the coronal, middle, and apical segments of the canals. Both disinfection methods successfully reduced the number of viable bacteria in all three canal preparation sizes.