Efficacy of Cryosurgery and Diode Laser on Clinical Outcomes of Gingival Repigmentation — A Systematic Review and Meta-Analysis

Gingival hyperpigmentation is a common aesthetic concern, particularly among individuals with a high smile line. Cryosurgery and diode laser therapy are widely used minimally invasive approaches for gingival depigmentation; however, their comparative clinical effectiveness remains uncertain. This systematic review and meta-analysis aimed to compare cryosurgery and diode laser therapy in the management of gingival hyperpigmentation with respect to depigmentation, postoperative pain, healing, and recurrence. The review was conducted according to PRISMA 2020 guidelines and registered in PROSPERO (CRD42024618472). MEDLINE/PubMed, Web of Science, Scopus, Embase, and Google Scholar were searched up to December 2024. Four split-mouth randomized controlled trials involving 75 participants were included. Outcomes were assessed using the Dummett Oral Pigmentation Index, Visual Analogue Scale for pain, and healing indices. Both techniques demonstrated effective gingival depigmentation. Diode laser generally showed lower postoperative pain and favorable clinical outcomes, although differences were not consistently statistically significant. Meta-analysis of pain scores showed a nonsignificant trend favoring diode laser (SMD −0.59; 95% CI −1.59 to 0.41; P = 0.25), with substantial heterogeneity (I² = 85%). Overall, both techniques appear effective, while current evidence is insufficient to establish clear superiority of either modality.