Probiotics in nonsurgical treatment of peri-implant diseases: A systematic review & meta-analysis

Background: Peri-implant disease is an inflammatory condition that affects implant stability and quality of life. As nonsurgical treatments show limited efficacy, probiotics have been explored for their anti-inflammatory effects. This systematic review evaluated the efficacy, safety, and health-related quality of life outcomes of peri-implant diseases. Methods: Databases were searched for randomized controlled trials (RCTs) and non-randomized studies (November 2024). The outcomes included bleeding on probing (BoP), probing depth, plaque index, and biomarkers. The protocol was registered with International Prospective Register of Systematic Reviews (CRD42024617103). The RoB in RCTs was assessed using the Cochrane Risk of Bias 2.0 tool, and non-RCTs using the RoB In Non-randomized Studies of Interventions tool. Evidence certainty was graded using the Grading of Recommendations, Assessment framework. Results: Fourteen studies were included, and 10 RCTs (n = 391) were meta-analyzed. For peri-implant mucositis, probiotics reduced BoP at 3 months (mean difference [MD] −1.45; P = .002) and 6 months (MD −9.44; P = .0003) and improved plaque index at 3 months (MD −0.99; P = .001). No effects on probing depth or peri-implantitis were observed. Tumor necrosis factor-alpha levels improved, while interleukin levels remained unchanged. Microbial analysis revealed no major changes. Subgroup analyses showed greater effects in placebo-controlled versus active comparator studies. Health-related quality of life and long-term safety were not assessed. Evidence certainty ranged from moderate to very low. Conclusion: Probiotics may provide modest short-term benefits for peri-implant mucositis by reducing BoP and plaque accumulation. Current evidence is insufficient to support its use in peri-implantitis or to establish long-term safety and patient-centered outcomes. Further high-quality long-term trials are required.