Effect of Low Level Laser Therapy on Postoperative Pain After Single Visit Endodontic Treatment: A Placebo-Controlled Randomized Clinical Trial

Objective: To evaluate the effect of low-level laser therapy (LLLT) on postoperative pain after root canal treatment. Methods: This study was designed as a randomized, single-blinded, placebo-controlled trial of 2 groups. Forty-two patients were included in the study according to the inclusion and exclusion criteria. The treatment procedures were performed by one operator. After local anesthesia and rubber dam isolation, access cavity preparation was performed by diamond burs with high-speed handpieces under the water cooling. Instrumentation of procedures was performed by Reciproc R50 files. Irrigation protocol was completed, canals were dried, filled with gutta-percha cones and AH Plus sealer. After chemo- mechanical instrumentation and root canal filling procedures, LLLT were applied for 60 seconds per tooth using Nd-YAG laser ( λ=1064 nm, 100 mJ, 10 Hz, 1-W) The same procedures as in the laser group were performed, been completed but the laser was not activated in this group. These patients were assigned as a placebo group. Postoperative pain was measured and documented via the Visual Analogue Scale. Results: The independent sample t-test was performed after normality and homogeneity tests. No statistically significant differences were detected between the groups in terms of demographic data (age and tooth number) (P > .05). No statistically significant difference was found between the groups at the 4th, 8th, 48th, and 72nd hours (p>.05). However, there was a statistically significant difference between groups at the 12th (p=.030) and 24th hours (p=.041). Conclusion: LLLT can decrease postoperative pain after root canal treatment of single-rooted teeth.