A comparative evaluation of postoperative re-pigmentation following gingival depigmentation using a 940-nm diode laser and abrasion method: “method: a split-mouth study”

Purpose: The aim of this study is to evaluate the re-pigmentation following gingival depigmentation procedure using a diode laser and abrasion method. Methods: A group of 20 patients (comprising 4 males and 16 females), aged between 12 and 37 years old, were selected for the study. Inclusion criteria involved patients exhibiting moderate to severe gingival hyperpigmentation on both the left and right sides of the anterior maxillae. Exclusion criteria included pregnancy and lactation, gingival hyperpigmentation associated with systemic conditions or lesions, patients with medical conditions, smokers, and patients under medication associated with hyperpigmentation. The study was designed as a split-mouth study, wherein the upper left anterior sextant of all subjects (from the first central incisor to the second premolar) was treated by abrasion method. Simultaneously, the upper right sextant (from the first central incisor to the second premolar) for the same patient was treated using a 940-nm diode laser. The laser settings comprised a power of 1.2 W and a pulse emission mode with an initiated tip (400 μm) placed in contact with the tissues. Both depigmentation techniques were performed on the same day by a single operator. Results: The results indicate a highly significant difference in the mean pigmentation index before treatment and after a 10-month period (p-value = 0.000). No statistically significant differences were observed in the mean pigmentation index between the laser and abrasion methods over the 10-month post-surgery duration. As for the association between patient complexion and re-pigmentation, 7 out of 16 patients with a brown complexion exhibited re-pigmentation, while no re-pigmentation was observed among patients with a fair complexion after a period of 10 months post-surgery. This indicates the presence of a direct relationship between patient complexion and re-pigmentation. Conclusions: Based on the study’s findings, both depigmentation methods were effective, with the laser technique notably safer and easier to perform compared to abrasion method. Interestingly, re-pigmentation could occur irrespective of the method used, indicating that individuals with brown or dark complexions had a higher likelihood of re-pigmentation compared to fair-skinned individuals. Considering these results, individuals genetically predisposed to gingival pigmentation should be informed about the potential for recurrence before the procedure, as sustained outcomes might not be guaranteed. © 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG.