Effects of Photobiomodulation Therapy in Lateral Luxation of Anterior Permanent Teeth: A Randomized, Double‐Blind Clinical Trial

BACKGROUND: Among the traumatic dental injuries (TDIs), lateral luxation may present poor prognosis due to frequent root resorption and consequent tooth loss. Photobiomodulation therapy (PBMT) modulates cellular activities (proliferation, differentiation, growth factor secretion) and may improve outcomes. OBJECTIVE: This randomized, double-blind, placebo-controlled trial evaluated PBMT (660 vs. 808 nm) for post-operative pain and pulp sensitivity recovery in lateral luxation of permanent anterior teeth. METHODS: Initially, 41 patients were included, with a total of 63 teeth traumatized by lateral luxation and were allocated to G1 (n = 21): Splinting + sham PBM (placebo), G2 (n = 21): Splinting + 808 nm infrared PBM and G3 (n = 21): Splinting + 660 nm red PBM. Four weekly sessions (3 J/point, 3 points) were administered. Pain (by numeric rating scale) and pulp sensitivity (by cold test) were assessed weekly. Pain was analyzed using the Kruskal-Wallis test, followed by multiple comparisons using Dunn's method with Bonferroni correction, and pulp sensitivity by a logistic regression model (p < 0.05). RESULTS: Three participants (total of 5 teeth) were excluded due to loss to follow-up. Fifty-eight teeth were analyzed (G1 = 21, G2 = 17, G3 = 20). Pain: All groups showed a significant reduction in pain over time (p < 0.001). Both G2 and G3 demonstrated a significantly greater reduction in pain compared to G1 (p < 0.001 and p = 0.026, respectively). No significant difference in pain reduction was observed between G2 and G3. Pulp sensitivity: G2 showed a significant improvement over time (p < 0.001), despite starting from a more unfavorable baseline. In contrast, no significant change in pulp sensitivity was observed for G1 or G3 between the initial and final assessments. CONCLUSION: Within the limitations of this clinical study, all intervention groups were effective in reducing pain in lateral luxation of permanent anterior teeth, with superior results for laser groups compared to the placebo. However, only the 808 nm laser irradiation protocol demonstrated a significant improvement in pulp sensitivity, suggesting it may offer a more complete therapeutic response.