McGowan K, et al. - An appraisal was performed with the intention of identifying the optimum dose and duration of amoxicillin-plus-metronidazole prescribed as an adjunct to non-surgical treatment of periodontitis. No significant variation was disclosed between varying doses or duration of amoxicillin-plus-metronidazole at three months post-treatment. In the absence of compelling evidence suggesting that any one regimen had performed superiorly, principles of responsible antibiotic use suggested the highest dose for the shortest duration of time. This would reduce the risk of antibiotic resistance. Hence, a 7-day regimen of 500/500mg or 500/400mg of amoxicillin and metronidazole would serve as the most appropriate therapy.