A Standardized Clinical Protocol for Comparing CO2, Er:YAG, and Diode Lasers in Oral Soft-Tissue and Peri-Implant Care

To compare the clinical performance, histopathological thermal injury, and postoperative recovery associated with CO₂, Er:YAG, and diode laser-assisted excision of peri-implantitis-associated inflammatory or hyperplastic soft tissue. In this randomized three-arm trial, 83 patients with peri-implantitis and a clinical indication for peri-implant soft-tissue excision were allocated to CO₂ (n=28), Er:YAG (n=28), or diode laser treatment (n=27). Seventy-five excised soft-tissue specimens, 25 per group, were evaluable for the primary histopathological endpoint. Maximum lateral thermal-damage width differed significantly among groups (P<0.001), with median values of 79.3 μm for CO₂, 33.6 μm for Er:YAG, and 112.6 μm for diode laser treatment. Er:YAG required longer operative time and more rescue hemostasis, whereas CO₂ and diode lasers provided faster procedures and better bleeding control. Median epithelialization time was 18, 16, and 20 days, respectively (P<0.001). Seven-day pain burden did not differ significantly (P=0.193). For adjunctive peri-implant soft-tissue management in patients with peri-implantitis, Er:YAG minimized thermal injury and accelerated healing, CO₂ offered the best overall balance, and the diode laser achieved efficient hemostasis at the cost of greater soft-tissue damage. These findings do not establish comparative efficacy for resolution of peri-implantitis.