AbstractBackground and objectivesThe aim of the present study was to analyze the effects of diode laser irradiation on the healing of human oral mucosa.Materials and MethodsAfter gingivoplasty, the right hemi‐arch (test group) of 16 patients was irradiated with a diode laser. The left side (control group) was not irradiated. Incisional biopsies were performed on both sides at 7, 14, 21, and 60 days after surgery and morphometrically analyzed by light microscopy.ResultsEpithelium width ranged from 260.6 to 393.5 μm. Volume densities of basal (20.2%), prickle cell (55.6%), and cornified (24.2%) layers remained stable. The peak number of neutrophils were 6 cells/mm2and the mononuclear cells were 44 cells/mm2. Collagen fibers (80%) and fibroblasts (14%) occupied the main volume of connective tissue. The one‐way ANOVA and the paired Student'st‐test were used for statistical analysis (P < 0.05).ConclusionLow‐level laser therapy did not accelerate the healing of oral mucosa after gingivoplasty. Lasers Surg. Med. 35:377–384, 2004. © 2004 Wiley‐Liss, Inc.