OR03 - Microbiological Study of Bacterial Load Reduction in the Root Canal System Utilizing a Novel Laser Activated Irrigation Technique

Abstract:
In this in vitro study, we aim to 1) assess biofilm removal efficacy at different root canal preparation sizes (17/.04V, 20/.04V, 25/.06V); and 2) evaluate the effectiveness of two Laser-Activated Irrigation (LAI) modes (Photon-Induced Photoacoustic Streaming - PIPS and Shock-Wave-Enhanced Emission Photoacoustic Streaming - SWEEPS) for biofilm removal. We collected 90 mandibular molars meeting inclusion criteria, sterilized them, and induced biofilm formation with a multi-species (Fusobacterium nucleatum, Enterococcus faecalis, and Prevotella intermedia) bacterial culture. The teeth were randomly assigned to three treatment groups: Needle irrigation (control), Fotona-SSP, and Fotona-SWEEPS, with subgroups based on preparation sizes. We assessed viable bacteria in mesial canals after irrigation and used confocal laser scanning microscopy (CLSM) to evaluate biofilm in the distal canal. Data were analyzed using one-way ANOVA and Tukey post hoc tests. Preliminary findings from a pilot study (n=12) showed no bacterial growth in the Fotona SWEEPS group, while the control group showed noticeable bacterial growth. The study will further investigate bacterial growth with varying irrigation mode and preparation size. This study explores the potential of LAI to enhance biofilm removal in endodontic treatment. It aims to identify the optimal root canal preparation size for efficient biofilm elimination through LAI and assess whether more robust LAI modes deliver superior results. These findings have the potential to improve root canal irrigation, advancing minimally invasive endodontics, and preserving pericervical dentin. Further research is needed to validate these preliminary findings and refine LAI's clinical application in endodontics.