Photobiomodulation for Controlling Pre-Local Anesthetic Injection Pain: A Double-Blind, Randomized Controlled Clinical Study

Dental fear and phobia are widespread worldwide, with local anesthesia being one of the procedures that patients fear the most. To alleviate the pain associated with needle insertion and the need for repeat procedures, various complementary therapies have been introduced. However, to date, there is no established protocol for this intervention. The objective of this study is to assess whether pre-anesthetic photobiomodulation (PBM) can effectively reduce needle puncture pain and enhance the efficiency of local anesthesia. In this double-blind randomized controlled trial, 50 participants were included. The control group underwent the standard anesthetic procedure, while the experimental group received the application of an infrared laser (100mW at 808nm, 8J at a single point) immediately before anesthesia, at the site of the intended needle puncture. Both groups underwent the same anesthetic procedure, administered by the same operator. The outcome evaluator and the patient were blind to the FBM application. The primary outcome of the study focused on pain experienced at the time of needle insertion, assessed using the Visual Analogue Scale (VAS) during the needle's introduction. Secondary outcomes encompassed anxiety levels, measured using the Beck questionnaire, anesthetic onset time determined through the electric pulp test, the number of anesthetics required for the procedure, and the necessity for supplementary anesthesia. Categorical variables will be presented as absolute and relative frequencies and compared using the Pearson chi-squared test, likelihood ratio test, or Fisher's exact test. Quantitative variables will be assessed for normality using the Kolmogorov-Smirnov test. Outcome variables will be presented as mean and standard deviation or median and interquartile range (IQR) and compared using the Student's t-test or Mann-Whitney test. Variables measured under multiple conditions will be compared using analysis of variance for repeated measures. A significance level of P < 0.05 will be considered statistically significant.