Microbiological Study of Bacterial Load Reduction in the Root Canal System Utilizing a Novel ErYagLaser

This study aimed to evaluate the effectiveness of a novel Er:Yag laser-activated irrigation technique in reducing bacterial load in root canals. In this study, mandibular molars are prepared and cultured with Enterococcus faecalis, and experiment was perform to test whether laser-activated irrigation could significantly reduce bacteria in the root canal system. The teeth were divided into four groups: Standard Needle Irrigation (SNI), Photon-Induced Photoacoustic Streaming (PIPS) – single pulse laser mode, Shock Wave Enhanced Emission Photo-acoustic Streaming (SWEEPS) – double pulse laser mode, and a baseline control. The study found no significant differences in bacterial load reduction between the different preparation sizes (20/.04v and 25/.06v) and irrigation techniques, except when compared to the baseline. However, trends indicated that SWEEPS had the highest efficacy, followed by PIPS and SNI. Confocal Laser Scanning Microscopy (CLSM) showed cleaner canal walls and better irrigant penetration in the SWEEPS group, with visible dead bacterial cells in the peripheral dentin. The results suggest that larger preparation sizes (25/.06v) are more effective than smaller ones (20/.04v), and that the stronger pulse energy mode (SWEEPS) may enhance irrigation effectiveness compared to the weaker mode (PIPS). Further investigation is needed to validate these findings comprehensively. The study highlights the importance of optimizing instrumentation sizes and laser parameters to improve endodontic treatment outcomes and reduce bacterial loads more effectively.