Purpose: To estimate and compare the effect of two different nonreconstructive surgical techniques for treating periimplantitis. Materials and Methods: An electronic search was performed in PubMed, Web of Science, Embase, Scopus, Ovid Medline, and the Cochrane Library of the Cochrane Collaboration (CENTRAL) for articles published until September 2023. Studies evaluating surgical nonreconstructive techniques for the treatment of peri-implantitis were included. The primary outcomes were changes in pocket probing depth (PPD) and bleeding on probing (BoP). Secondary outcomes included marginal bone levels (MBLs) and plaque index (PI) changes. Meta-analysis and meta-regression were performed. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to determine the quality of evidence. Results were grouped according to their treatment techniques: (1) flap surgeries and (2) osseous resective surgeries (nonreconstructive). Results: The final stage of screening included 15 clinical trials. At 12 months, the flap group had a mean PPD reduction of 1.27 mm (95% CI: 0.67–1.87; I2 = 95.9%), and the osseous resective group had a PPD reduction of 1.88 mm (95% CI: 1.39–2.37; I² = 97.1%), showing no significant differences (P = .119). Regarding BoP, there were no significant differences between the two techniques at 3, 6, or 12 months. For MBL, at 12 months, the flap group showed less bone loss than the osseous resective group (mean difference = 0.73 mm; P < .001). Conclusions: Both nonreconstructive surgical interventions were effective in managing peri-implantitis. Moderate-quality evidence suggested that flap surgeries may provide a slight advantage in maintaining MBLs compared to osseous resective surgery.