(PO137) Efficacy of Er,Cr:YSGG (EdgePro™, EdgeEndo®) and Diode Laser (LEAP™, CAO group, inc) in Reducing Bacterial Infection in Root Canal Treatment

Abstract: To evaluate the efficiency of lasers in the elimination of E. faecalis biofilm during chemo-mechanical preparation of root canals, E. faecalis (OG1RF) was grown at 37°C, at 5% CO₂. Once OD₆₀₀ = 0.8 was established, suspensions were serially diluted, and an E. faecalis inoculum (10⁵ cells) was used. Intracanal biofilms were grown in extracted premolars (n=36) submerged in media. Biofilms were developed for 21 days and analyzed with culture and SEM. Experimental groups included a standard irrigation protocol (SIP) (3% NaOCl, 17% EDTA) (n=6), SIP plus EdgePRO^TM (n=6) or LEAP^TM (n=6), and PBS plus EdgePRO (n=6) or LEAP (n=6). Negative controls consisted of PBS irrigation alone (n=6). The antimicrobial effect of the LEAP ICG dye was assessed using disk diffusion assays. ANOVA analysis was used; a p-value < .05 was considered significant. SIP plus laser activation for both groups showed significant bacterial reduction, exhibiting fewer mean CFU/ml on agar plates and cleaner dentinal tubules in SEM images. The mean CFU for the negative control was (203.5 ± 272.2), and LEAP only was (1.5 ± 0.71). SIP plus LEAP led to the complete elimination of microorganisms and enhanced the opening of dentinal tubules. EdgePRO alone was similar to the negative control group for culture and SEM analysis. No zones of inhibition were recorded in 1 week around the ICG dye disks. Adjunctive laser activation of SIP reduced E. faecalis biofilms for both groups. In the absence of a chemical irrigant, only LEAP reduced E. faecalis biofilms.