RESUMEN
OBJECTIVE: Vitamin C/Ascorbic acid inhibits tyrosinase enzyme causing melanin biosynthesis suppression. This study aimed to compare the efficacy of intra-mucosal injection (mesotherapy) with topical gel as non-surgical methods for managing gingival hyperpigmentation. MATERIALS AND METHODS: Twenty healthy non-smokers with mild to severe hyperpigmented gingiva were randomly assigned for Mesotherapy (G1); intra-mucosal injection of ascorbic acid (1/week/3 weeks); or Gel (G2), topical ascorbic acid gel (1/day/3 months). Pigmentation index (DOPI), patient satisfaction, as well as histological analysis for Fontana-Masson-stained specimens were performed at baseline and after 6 months. Comparison between groups and changes by time were analyzed using Mann-Whitney and Friedman's tests, respectively. RESULTS: The median DOPI significantly decreased after 1 month in G1 (P value < 0.001, r = 0.9) compared with non-significant change in G2. No pain experienced during or after treatment in both groups. G1 patients showed significantly higher satisfaction with treatment than G2. Mean area fraction of melanin forming cells was significantly reduced in both groups after 6 months, but the effect size was higher in G1 (r = 0.886) than in G2 (r = 0.797). CONCLUSIONS: Vitamin C mesotherapy showed better and early effect than topical gel, and both techniques were not painful and esthetically satisfying in managing gingival hyperpigmentation. CLINICAL RELEVANCE: Gingival melanin pigmentation causes esthetic concerns for significant number of patients. Investigating non-surgical depigmentation techniques to decrease postoperative complications and patient discomfort, pain and long healing period associated with surgical methods would be clinically significant.