Effect of adjunctive amoxicillin/metronidazole treatment on the recolonization levels of subgingival Tannerella forsythia, Prevotella intermedia and Fusobacterium nucleatum in periodontitis patients

Background: The use of antibiotics adjunctive to non-surgical periodontal treatment is an accepted approach in the treatment of periodontitis. However, bacterial recolonization is a major drawback which complicates the maintenance of therapeutic acquisitions. The aim of this study was to evaluate the clinical and microbiological effects of adjunctive amoxicillin and metronidazole combination in the treatment of periodontitis during 6 months follow-up. Materials and Methods: Twenty-two periodontitis patients were assigned as test (n=12) and control (n=10) groups. While test group received amoxicillin and metronidazole combination as an adjunct to scaling and root planing, control group treated with scaling and root planing alone. Clinical examinations and subgingival dental plaque sampling were conducted at baseline and 1, 3 and 6. months during the follow-up. Fusobacterium nucleatum, Tannerella forsythia and Prevotella intermedia levels were determined using real time polymerase chain reaction method. Results: Both groups exhibited significant improvements in each follow-up period when compared to baseline. However, clinical improvements in test group were more prominent than control group as 3rd and 6th months. While some decrease was notable in the counts of all investigated bacteria in both groups, only T. forsythia levels significantly reduced at all follow-up months in test group comparing with controls. Conclusion: The results of this study indicated that amoxicillin/metronidazole treatment adjunctive to scaling and root planing provided additional clinical benefits and suppressed the T. forsythia recolonization