Effect of Photobiomodulation Therapy with 915 nm Diode Laser on Pain Perception during Local Anesthesia of Maxillary Incisors: A Randomized Controlled Trial.

This study aimed to evaluate the effect of photobiomodulation therapy (PBMT) with 915 nm wavelength on pain reduction during maxillary incisors' local infiltration in a randomized clinical trial study. A prospective triple-blinded split-mouth clinical trial was designed to assess pain perception during needle insertion and local anesthetic injection in 32 healthy patients required operative caries management on contralateral maxillary incisors. After laser treatment (915 nm, power of 1.5 W, duty cycle of 60% and energy density of 72 J cm<sup>-2</sup> ) in active group and no irradiation in sham group, the injection was performed. Patients' perception of pain was immediately assessed using numerical rating scale (NRS) for pain. Washout period between two appointments was one week. Wilcoxon signed-rank and Pearson correlation statistical analyses were used to assess the comparison of pain score between two appointments and the effect of anxiety level of previous dental injections. The mean scores of pain for the active laser and sham laser groups were 2.5 ± 2.19 and 4.34 ± 2.52, respectively, with a statistically significant higher NRS in the sham laser group (P ˂ 0.05). In this study's condition, diode PBMT reduced pain during infiltration on maxillary incisors. Anxiety experience of dental injection had no significant effect on pain perception scale (P ˃ 0.05).