Minimally invasive gingival depigmentation using microneedling combined with ascorbic acid: a systematic review

Gingival hyperpigmentation is a common aesthetic concern. Although conventional depigmentation techniques are effective, they may be associated with postoperative discomfort, delayed healing, and recurrence. Microneedling combined with ascorbic acid has emerged as a minimally invasive alternative, but the available evidence remains limited and heterogeneous. A PRISMA-compliant systematic review registered in PROSPERO (CRD42024613667) was conducted. PubMed, Google Scholar, Wiley Online Library, and Scopus were searched for clinical studies evaluating microneedling with ascorbic acid for gingival depigmentation. Risk of bias was assessed using RoB 2 and Joanna Briggs Institute appraisal tools. Findings were synthesised qualitatively according to study design, and certainty of evidence was assessed using GRADE. Seven studies met the eligibility criteria, including four randomised controlled trials, two case series, and one case report. Microneedling with ascorbic acid consistently reduced gingival pigmentation and generally improved patient-reported outcomes, particularly postoperative discomfort. However, findings regarding wound healing and recurrence were variable. Overall, the certainty of evidence ranged from low to very low across the evaluated outcomes. The available evidence suggests that microneedling combined with ascorbic acid is a promising minimally invasive option, although confidence in the findings is limited by clinical heterogeneity and low to very low certainty of evidence. Microneedling combined with ascorbic acid may be a promising minimally invasive approach for physiologic gingival hyperpigmentation, offering favourable short-term outcomes with reduced postoperative discomfort. However, evidence remains insufficient to confirm long-term durability or superiority over established depigmentation techniques. Further well-designed randomised controlled trials with standardised protocols and longer follow-up are needed.