Meta-analysis of randomized controlled trials: efficacy of vitamin C mesotherapy for gingival hyperpigmentation in adults.

Background: Gingival hyperpigmentation is a common aesthetic concern, necessitating evidence-based evaluation of depigmentation treatments, particularly vitamin C mesotherapy.

Methods: A systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted across PubMed, EMBASE, and Web of Science databases. Data were extracted and analyzed using both random and common effects models to calculate mean difference (MD) and 95% confidence interval (CI). Heterogeneity was assessed using I², tau², and Q statistics.

Results: The meta-analysis, including 11 RCTs with a total of 236 participants, revealed significant effects of vitamin C mesotherapy. For Visual Analog Scale (VAS) scores, the MD was 2.0580 [1.6161; 2.4998] (p < 0.0001), with high heterogeneity (I² = 90.6%). The overall effect for GPI scores was not statistically significant (MD = -0.72, 95% CI [-1.47, 0.03], p = 0.0585), with high heterogeneity (I² = 95.1%). A subgroup analysis revealed a significant difference between groups (p < 0.0001). The Diode laser subgroup showed a significant effect (MD = -1.35, 95% CI [-1.64, -1.07]) with no heterogeneity, whereas the Surgical depigmentation subgroup had no significant effect and high heterogeneity (I² = 85.9%). Dummett-Gupta Oral Pigmentation Index (DOPI) scores showed a significant decrease with mesotherapy compared to diode laser (MD = -0.7653 [-0.9207; -0.6100], p < 0.0001, I² = 0.0%), but no significant difference compared to topical gel (MD = 0.1723 [-0.1438; 0.4883], p = 0.2855, I² = 0.0%). When compared to overall laser interventions (MD = 1.7245 [1.5181; 1.9308], p < 0.0001, I² = 89.9%) and surgical interventions (MD = 2.2091 [2.0653; 2.3530], p < 0.0001, I² = 59.5%), vitamin C mesotherapy generally exhibited smaller mean differences, indicating a comparatively lesser magnitude of effect.

Conclusion: Vitamin C mesotherapy demonstrates significant efficacy in reducing gingival hyperpigmentation, notably showing a favorable outcome compared to diode laser for DOPI scores and no significant difference from topical gel. While laser and surgical interventions generally present larger overall mean differences, vitamin C mesotherapy remains a valuable treatment modality, adding to the diverse effective options for managing gingival hyperpigmentation.