Adjunctive Antimicrobial Therapy in Peri-Implant Diseases: A Narrative Review

Background: Effective management of peri-implant disease relies primarily on mechanical removal of the bacterial biofilm. However, achieving adequate surface decontamination can be challenging due to complex implant-surface morphology and restricted access to deep peri-implant pockets. This has prompted the use of adjunctive antimicrobial agents to complement mechanical therapy and improve therapeutic outcomes. Objective: To investigate whether the adjunctive use of antimicrobial strategies improves clinical, microbiological, and radiographic outcomes in patients with peri-implant mucositis and peri-implantitis. Materials and Methods: A structured narrative review was conducted using PubMed/MEDLINE and Scopus in July 2026. No database filters concerning language, human participants or study design were applied. During the screening process, only randomized controlled clinical trials involving human participants and available as English-language full texts were selected. Eligible interventions included locally or systemically administered antibiotics, antiseptics, antimicrobial drug-delivery systems, antimicrobial photodynamic therapy (aPDT), ozone-based therapies, and microbiome-modulating adjuncts. Conventional laser therapy was not classified as an eligible antimicrobial intervention. The database searches retrieved 462 records, including 252 from PubMed and 210 from Scopus. Following duplicate removal and eligibility assessment, 100 publications representing 93 independent clinical trials were included. Results: adjunctive antimicrobial efficacy was highly variable and appeared to depend on disease severity, debridement strategy, antimicrobial agent, delivery modality, and follow-up period. Repeated or sustained local antimicrobial delivery was associated with modest, short-term benefits in several studies, whereas chlorhexidine (CHX) generally provided limited additional benefit over mechanical therapy. Evidence for systemic antibiotics remained inconsistent and insufficient to support routine use, while aPDT offered potential benefits that varied according to treatment protocol. Ozone therapy, herbal agents, and novel drug-delivery systems yielded encouraging preliminary results, although evidence remains scarce. Moreover, reductions in bleeding and probing depth (PD) did not reliably correspond to superior microbiological outcomes, radiographic bone gain, or complete disease resolution. Conclusions: Mechanical debridement (MD) and effective plaque control remain central to peri-implant disease management. Some adjunctive interventions produced modest short-term improvements in individual studies; however, the available evidence does not demonstrate durable disease control or support routine use. Therapeutic decisions should be tailored to disease severity, patient and implant characteristics, and the balance between potential benefits and antimicrobial-associated risks. Further well-designed and adequately powered randomized controlled trials with extended follow-up periods are needed to establish more definitive recommendations.