Systemic antibiotic therapy as an adjunct to non-surgical peri-implantitis treatment: A single-blind RCT

The aim of this single-blind RCT was to evaluate the adjunctive clinical and microbiological effect of systemic amoxicillin (AMX) plus metronidazole (MTZ) to non-surgical treatment of peri-implantitis.

Patients (N = 62) with peri-implantitis were randomly assigned to receive full-mouth mechanical debridement and decontamination and use of chlorhexidine (control group) or combined with antibiotic therapy of AMX/MTZ (test group). Primary outcome was change in bleeding score from baseline (T₀ ) to 3-month follow-up (T₃ ). Secondary parameters were plaque, suppuration, PPD, CAL, bone level, microbiology, adverse events and need for additional surgery. Data were analysed with linear multiple regression analysis.

57 patients with 122 implants completed 3-month follow-up. Both groups showed major clinical improvements at T₃ in both peri-implant and periodontal parameters. However, no significant differences were observed between both groups for any of the primary or secondary parameters.

Systemic antibiotic therapy of AMX/MTZ does not improve clinical and microbiological outcomes of non-surgical peri-implantitis treatment and should not be routinely recommended. Although complete disease resolution may be difficult to achieve, meticulously performed full-mouth non-surgical treatment, achieving a high level of daily oral hygiene and healthy periodontal tissues, can significantly improve the starting position of the subsequent (surgical) peri-implantitis treatment phase.