Effect of diode laser on oral pigmentation, pain, and wound healing in patients with gingival hyperpigmentation: a meta-analysis

Objectives: Diode laser represents a practical clinical strategy for treating gingival hyperpigmentation. However, its effectiveness remains controversial. The aim of this meta-analysis was to evaluate the quantitative effects of diode laser therapy on gingival hyperpigmentation.
Method and materials: PubMed, Embase, Web of Science, and Cochrane Library were systematically searched for the use of diode laser in gingival hyperpigmentation. The primary outcomes assessed were the Dummett-Gupta Oral Pigmentation Index (DOPI), visual analog scale pain scores, and the Wound Healing Index (WHI) for overall evaluation. The I2 index was calculated to identify heterogeneity, and sensitivity analyses were performed to identify sources of heterogeneity. Funnel plots and the Egger test were utilized to evaluate publication bias.
Results: Thirteen randomized controlled trials involving a total of 233 participants were included in the study. The analysis demonstrated that diode laser had a significant effect on DOPI (standard mean difference [SMD] = −0.245, 95% CI −0.451 to −0.040, P = .019) and pain (SMD = −0.809, 95% CI −1.332 to −0.285, P = .002), with no significant effect on WHI (SMD = −0.224, 95% CI −1.100 to 0.653, P = .617). Despite the significant heterogeneity in VAS and WHI indicated by the I2 index statistic, the sensitivity analyses’ results demonstrated the main findings’ reliability. While no significant publication bias was detected for DOPI and WHI, the pain results exhibited notable publication bias.
Conclusion: The study demonstrated that diode laser prolongs gingival repigmentation time and reduces pain compared to other treatments. However, efficacy in wound healing was not significantly affected.