Background: Microorganisms and their by products are considered to be the major cause of pulp and periradicular pathosis. Root canal infection has multibacterial etiology. The success of the endodontic treatment is directly influenced by the elimination of microorganisms from infected root canals. Many authors have suggested that to eliminate bacteria from the root canals predictably, the adjuvant method or agent is recommended. Aims: The present study was conducted to evaluate and compare the efficacy of Er:YAG laser, 2% Chlorhexidine and 3% sodium hypochlorite for disinfection of root canal. Methodology: In sixty single rooted teeth, access opening and instrumentation till #25 file was done under rubber dam. The first sample was collected by introducing a sterile paper point for preoperative microbial sampling. Twenty teeth in each group were treated with Er:YAG laser, 2% Chlorhexidine and ultrasonic irrigation 3% sodium hypochlorite using for disinfection of root canal. The second sterile paper point was placed to collect the postoperative sample. Paper points were put in a test tube containing transport medium and sent for microbiology laboratory. Results: According to the results of the present study, there was highly significant difference (P < 0.0001) in percentage reduction in all the three study groups. There was a statistically highly significant difference (P < 0.0001) in pre and post operative colony forming units in samples treated with ultrasonic irrigation with 3% sodium hypochlorite (Group III). Conclusions: In the current study, ultrasonic irrigation with 3% sodium hypochlorite was the most effective treatment modality as compared to Er:YAG laser and 2% Chlorhexidine for disinfection of root canal
Key words: 3% sodium hypochlorite, disinfection, Er:YAG laser, 2% Chlorhexidine, ultrasonic irrigation.