Combination of tetracycline and metronidazole in the treatment and control of refractory periodontitis.

Nine patients with refractory periodontitis were selected for this study. Each patient had undergone surgery once or twice in the previous five years and had been on three-month recall for clinical examination and scaling. During the maintenance phase of therapy and despite regular scaling, each patient had additional pocket formation that was either localized or generalized. Pocket depths in each patient were recorded and scaling was carried out. Three months later the patients were examined, and again no improvement was observed in the pocket depths. This time all patients were scaled again, and 250 mg tetracycline every six hours for 20 days as well as 250 mg metronidazole every eight hours for seven days were systemically administered. After an additional three months, patients were again examined and pocket depths measured. The latter examination disclosed that the clinical condition of the gingiva, as shown by bleeding and exudate, had improved. The pocket depths had also been reduced. The scaling-alone mean pocket depths were 4.93 mm, whereas the scaling-plus-antibiotic measurements were reduced to 2.78 mm. The difference was significant (p = 0.01).