In vitro evaluation of periapical safety of various laser-activated irrigation protocols using a quantitative assessment method

Context: Successful root canal treatment (RCT) depends on effective irrigant activation to enhance disinfection and minimize the risk of apical periodontitis. Laser-activated irrigation (LAI) has shown promise; however, its periapical safety remains to be fully evaluated. Aims: The aim of this study was to assess and compare the periapical safety of erbium:yttrium-aluminum-garnet (Er:YAG) and diode laser irrigation protocols with passive ultrasonic irrigation (PUI) during RCT. Settings and Design: This was a quantitative in vitro experimental study. Methods: Sixty-six extracted human single-rooted teeth were standardized and fixed into a 96-well plate containing 300 μL of a pH indicator solution. Teeth were randomly allocated to three groups: PUI, diode laser, and Er: YAG laser. Irrigation with 5.25% sodium hypochlorite (NaOCl) was activated using the designated technique. Apical extrusion of NaOCl was quantified using ELISA-based spectrophotometry. Statistical Analysis Used: Kruskal–Wallis and post hoc pairwise comparison tests were performed ( P < 0.05). Results: All groups showed apical extrusion. The Er:YAG group had significantly less extrusion than the diode and PUI groups ( P < 0.05). Conclusions: Within the study’s limitations, Er:YAG and diode LAI reduced apical NaOCl extrusion compared to PUI, indicating improved periapical safety. Further clinical studies are needed.