Comparative Evaluation of Photobiomodulation and Intracanal Cryotherapy on Post-Endodontic Pain Following...

Background Postoperative pain following root canal treatment (RCT) remains a clinically relevant concern despite continuing refinements in endodontic technique. This randomized controlled trial aimed to evaluate and compare the analgesic efficacy of photobiomodulation therapy (PBMT) and intracanal cryotherapy in reducing post-endodontic pain following a single-visit RCT. Methods Ninety adults requiring RCT of an asymptomatic mandibular first molar were allocated by computer-generated randomization into three parallel groups (n = 30 each): Group 1 (Control), final irrigation with 20 mL of room-temperature saline; Group 2 (PBMT), final saline irrigation followed by intraoral transmucosal 940 nm diode laser irradiation at 0.1 W for 40 s at each of four mucosal points (4 J per point; 16 J total per session); and Group 3 (Cryotherapy), final irrigation with 20 mL of chilled saline (2°C-4°C). Postoperative pain was assessed using a visual analog scale (VAS) at 6, 24, and 48 hours and at 7 days, with parallel recording of rescue analgesic intake. Intergroup comparisons of the non-normally distributed pain and analgesic data used the Kruskal-Wallis test; categorical data were compared by the chi-square test (α = 0.05). Results No statistically significant intergroup differences in VAS pain scores or analgesic intake were observed at any time point (p > 0.05). The cryotherapy group recorded the lowest mean pain score at six hours (0.53 ± 0.90) and the PBMT group at 24 hours (0.33 ± 0.76). All three groups reached a VAS of 0 by day 7, and no analgesic was consumed in any group at day 7. Conclusions Within the limits of this trial, neither PBMT nor intracanal cryotherapy conferred a statistically significant analgesic advantage over conventional saline irrigation following single-visit RCT in asymptomatic patients. As this population had minimal preoperative pain, the result should not be extrapolated to symptomatic patients, in whom adjunctive therapies may still be beneficial. This indicates that, in asymptomatic cases, meticulous canal disinfection and adherence to fundamental endodontic principles remain the principal determinants of postoperative outcomes.