Adjunctive benefits of systemic metronidazole on non‐surgical treatment of peri‐implantitis. A randomized placebo‐controlled clinical trial

Abstract Aim To study clinical, radiographic, and microbiological outcomes after non‐surgical therapy of peri‐implantitis with or without adjunctive systemic metronidazole. Materials and Methods A randomized placebo‐controlled clinical trial was carried out in 32 subjects (62 implants) diagnosed with peri‐implantitis. Implants received a mechanical non‐surgical debridement session and systemic metronidazole or placebo. Clinical, radiographic, and microbiological outcomes were evaluated at baseline, 3, 6, and 12 months. Results After 12 months, the test treatment resulted in significantly greater PPD reduction (2.53 vs. 1.02 mm) and CAL gain (2.14 vs. 0.53 mm) ( p value <.05) in comparison with placebo. The test treatment also resulted in additional radiographic bone gain (2.33 vs. 1.13 mm) compared with placebo ( p value <.05). There was a significantly greater decrease in Porphyromonas gingivalis , Tannerella forsythia , and Campylobacter rectus counts compared with the control group ( p value <.05). At the end of follow‐up, 56.3% of patients met the success criteria in the test group and 25% in the control group. Conclusions The use of systemic metronidazole as an adjunct to non‐surgical treatment of peri‐implantitis resulted in significant additional improvements in clinical, radiographic, and microbiological parameters after 12 months of follow‐up. This study is registered in ClinicalTrials.gov (NCT03564301).