Bactericidal Effect of 2780 nm Er,Cr:YSGG Laser Combined with 940 nm Diode Laser in Enterococcus faecalis Elimination: A Comparative Study

Objective: This study aims to compare the bactericidal efficacy of different Er,Cr:YSGG disinfection methods, particularly combined application of Er,Cr:YSGG and Diode laser. Background: Root canal disinfection is important for long-term endodontic success. Different laser systems are proposed as alternatives to conventional techniques in bacterial elimination. Materials and methods: Ninety-five straight, single-rooted premolars with similar canal dimensions were selected. After the mechanical preparation, the samples were sterilized, and root canals were infected with Enterococcus faecalis. The samples were randomly divided into five groups (n=15): 5% NaOCl, Er,Cr:YSGG, Er,Cr:YSGG +5% NaOCl, Er,Cr:YSGG + Diode, and control group. Results: The maximal bacterial elimination was observed in Er,Cr:YSGG + NaOCl group (p<0.005). More bacteria were found in Er,Cr:YSGG and Er,Cr:YSGG + Diode groups compared with 5% NaOCl group (p<0.005). Marginal significance was detected between the Er,Cr:YSGG group and the Er,Cr:YSGG + Diode group (p=0.091). Conclusions: The most successful E. faecalis elimination was obtained from laser-activated irrigation group. As combined application of Er,Cr:YSGG and Diode laser gives suggestive results, further studies with larger sample sizes are needed to clarify the outcome.