Comparative evaluation of antimicrobial efficacy on Enterococcus faecalis and smear layer removal in curved canals by different irrigation techniques: An in vitro study

BACKGROUND: Various irrigation techniques have been proposed to improve the effectiveness of root canal debridement. AIMS: The aim of the study was to compare the antimicrobial effect on Enterococcus faecalis and smear layer removal efficacy in curved canals by different irrigation techniques. MATERIALS AND METHODS: Eighty extracted permanent maxillary molars with curved mesiobuccal roots were inoculated with E. faecalis. The tooth samples were then divided into four groups: Group A – EndoVac, Group B – Passive Ultrasonic Irrigation (PUI), Group C – Photodynamic Therapy (PDT), and Group D – Laser Irrigation with Photon-Induced Photoacoustic Streaming (PIPS). The percentage of bacterial reduction was calculated. The presence of smear layer from coronal, middle, and apical sections was evaluated through scanning electron microscopy. STATISTICAL ANALYSIS: Statistical analysis was performed using Kruskal–Wallis test. Intergroup comparison was made with Mann–Whitney U-test. RESULTS: Although statistically insignificant, the irrigation techniques have shown considerable reduction in E. faecalis biofilm (P > 0.05). EndoVac, PUI, and PIPS have shown significantly higher efficacy in removing smear layer from apical third than PDT (P < 0.001). CONCLUSION: The newer PIPS technology can be used as an efficient tool in the decontamination of root canals. However, more clinical studies in this aspect are required to ensure more thorough debridement and disinfection of the root canal system.