Photobiomodulation reduces pain from dental injections in children by 1.25 points on Wong-Baker scale

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The journal of evidence-based dental practice Published June 1, 2026 Medically reviewed June 1, 2026 Study authors: Amrollahi Narjes, ADEl Seyed Amir Reza, Tarrahi Mohammad Javad, Kalantari Maryam PubMed ↗ DOI ↗ By Dr. Sofia Müller, MD · Lifespan & Whole-Person Care

Key Takeaway

Consider photobiomodulation to reduce injection pain in children, but evidence is limited and safety unreported.

This systematic review and meta-analysis examined the effect of low-level laser therapy (LLLT) or photobiomodulation therapy (PBMT) on pain in children undergoing dental local anesthetic injections. The analysis included 8 articles, with 6 contributing to the meta-analysis. The primary outcome was the Wong-Baker pain score.

Pooled results showed a significant reduction in pain favoring PBMT, with a mean difference of -1.25 (95% CI: -2.43 to -0.07, P = .039). Subgroup analysis using a 960 nm wavelength with gel-inactive laser control also showed significant reductions: Wong-Baker score mean difference -1.30 (95% CI: -2.17 to -0.43, P < .001) and FLACC scale mean difference -1.06 (95% CI: -1.68 to -0.45, P < .001).

The authors did not report adverse events, serious adverse events, discontinuations, or tolerability. Limitations of the review were not explicitly stated. The practice relevance is that PBMT may be effective for reducing pain during anesthetic injections in children, but the evidence base is small and safety data are absent.

Study Details

Study typeMeta analysis

EvidenceLevel 1

PublishedJun 2026

PMID42114940

View Original Abstract ↓

OBJECTIVES: Managing pain effectively during dental procedures is crucial, especially for children undergoing local anesthetic injections. Low-level laser therapy (LLLT), or photobiomodulation therapy (PBMT), has been investigated as a non-invasive method to reduce injection discomfort. DATA SOURCES: A comprehensive search of PubMed, Scopus, Cochrane Library, Embase, and Web of Science was conducted up to June 2024 to identify randomized controlled trials (RCTs) evaluating PBMT for pain reduction. Study quality was assessed using the Cochrane Risk of Bias Assessment Tool 2 (RoB2) by 2 independent reviewers. Meta-analysis was performed using STATA version 17 on data from studies. Heterogeneity was assessed using chi-squared, tau, and I statistics. A random-effects model was employed, and publication bias was evaluated using funnel plots and Begg and Egger's tests. RESULTS: Eight articles met the inclusion criteria, with 6 included in the meta-analysis. The analysis showed a significant reduction in Wong-Baker pain score in children receiving PBMT compared to control groups (mean difference = -1.25, 95% confidence interval (CI): -2.43 to -0.07, P = .039). Meta-analysis based on a specific range of wavelength (960 nm) and consistent control groups (anesthetic gel with an inactive laser), confirmed a significant reduction in Wong-Baker (mean difference = -1.30, 95% CI: -2.17 to -0.43, P < .001) and face, legs, activity, cry, and consolability (FLACC) scale (mean difference = -1.06, 95% CI: -1.68 to -0.45, P < .001) pain scores. CONCLUSION: PBMT was found to be effective in reducing pain during anesthetic injections in children. The application of PBMT (960 nm) compared to a gel-inactive laser control group shows promise based on the Wong-Baker and FLACC scales.