Antimicrobial therapy in periodontitis: the use of systemic antimicrobials against the subgingival biofilm


  • Conflict of interest and source of funding statement
    The authors declare that they have no conflict of interests.
    The 6th European Workshop on Periodontology was supported by an unrestricted educational grant from Straumann AG.
    No funding was provided for this paper.

David Herrera
Faculty of Odontology
Universidad Complutense
Plaza Ramón y Cajal, s/n
Madrid 28040


Objectives: The aim was to answer three relevant questions: can systemic antimicrobials be efficacious if the biofilm is not disrupted? Can the type of debridement of the subgingival biofilm impact upon the clinical outcomes of the adjunctive antimicrobial therapy? Is the efficacy of the adjunctive systemic antimicrobial therapy dependent on the quality of the debridement of the subgingival biofilm and the sequence debridement–antibiotic usage?

Material and Methods: Relevant papers were searched, critically analysed and their data were extracted.

Results: For the first question, studies assessing susceptibility of bacteria in biofilms, and clinical studies evaluating systemic antimicrobials as monotherapy, were reviewed. For the second question, clinical studies comparing systemic antimicrobials as adjuncts to non-surgical debridement or to periodontal surgery and clinical trials using systemic antibiotics with periodontal surgery were evaluated. For the third question, a previous systematic review was updated.

Conclusion: If systemic antimicrobials are indicated in periodontal therapy, they should be adjunctive to mechanical debridement. There is not enough evidence to support their use with periodontal surgery. Indirect evidence suggests that antibiotic intake should start on the day of debridement completion, debridement should be completed within a short time (preferably <1 week) and with an adequate quality, to optimize the results.