This pilot randomized clinical trial aims to evaluate the effect of adjunctive acid application on the esthetic outcomes of gingival melanin depigmentation. Participants with physiologic gingival hyperpigmentation will be randomly assigned to receive conventional gingival depigmentation with or without adjunctive acid application. The primary outcome is the improvement in gingival esthetics, while secondary outcomes include postoperative healing, pain, patient satisfaction, and recurrence of pigmentation. The findings of this study may help identify whether adjunctive acid application improves the clinical outcomes of gingival depigmentation procedures.