IRCT20200309046728N1 IRCT 2020-04-16 Esfahan University of Medical Sciences Investigation of the effect of laser on darkening of the gums Comparative study of the effect of two types of diode and CO2 lasers in the treatment of gingival pigmentation (with 3 months follow-up) 2019-11-21 anticipated 16 Complete https://irct.ir/trial/46394 interventional Randomization: Randomized, Blinding: Single blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment, Randomization description: Maxillary gingiva of each patient was split into right and left halves (Split Mouth technique). One half was treated by diode laser and the other half by CO2 laser. The divided areas were randomly allotted for depigmentation by coin toss, Blinding description: Experts reviewing the results of the two interventions are also unaware of the type of intervention done on the patients' gingival sites. In order to achieve the goals of blindness in this study, it needs to be explained that the expert doing the surgical procedure is different from the one evaluating the results of the two surgical procedures and the expert evaluate is completely unaware of the type of surgical method used in the surgical sites and is selected from outside of the surgical team. N/A Gingival pigmantation. Intervention 1: Intervention group: CO2 laser. The segments in this group underwent gingival depigmentation with CO2 laser at Super Dream Pulse and non-contact mode. the operation will be done in one session that takes about an hour. Intervention 2: Intervention group: Diode Laser. The segments in this group underwent gingival depigmentation with diode laser (980 nm) at continuous and contact mode. the operation will be done in one session that takes about an hour. No - There is not a plan to make this available Justification or reason for not sharing IPD is No more information