Systemic antimicrobials have been used as an adjunctive therapy for the treatment of periodontitis. Nevertheless, it is unclear whether the use of antimicrobials may improve tooth survival in patients with periodontitis. The main objective of this overview of systematic reviews (SRs) with meta-analyses was to assess the evidence supporting systemic antimicrobials for improving tooth survival in patients suffering from periodontitis. Information on adverse events was also extracted from SRs.PubMed and EMBASE databases were searched independently (up to 1st August 2013) to identify SRs with meta-analyses on the use of systemic antimicrobials as an adjunctive treatment to scaling and root planing (SRP) in the treatment of periodontitis. Tooth survival and adverse events were assessed. Clinical effect was also assessed based on endpoints including clinical attachment level and probing depth. The methodological quality of the SRs was assessed by two authors using two checklists (AMSTAR and OQAQ).No data on tooth survival after treatment with SRP and antimicrobials were found. Nine SRs were included in this overview. Three SRs showed statistically significant outcome improvement with the use of antimicrobials, although the clinical relevance may be questionable. One SR showed better results based on surrogate endpoints; however, short-term adverse events were more pronounced with the use of antimicrobials. The reporting of long-term data on clinical effects, adverse events and bacterial resistance is scarce. The SRs were of heterogeneous quality.Evidence of the efficacy of systemic antimicrobials on improving tooth survival is lacking. Further research focused on tooth survival and adverse events should be performed to provide more robust evidence of the benefits of using systemic antimicrobials for treating periodontitis.