A 15-month evaluation of the effects of repeated subgingival minocycline in chronic adult periodontitis

Background: A double-blind, randomized, parallel, comparative study was des igned to evaluate the long-term safety and efficacy of subgingivally admini stered minocycline ointment versus a vehicle control. Methods: One hundred four patients (104) with moderate to severe adult peri odontitis (34 to 64 years of age; mean 46 years) were enrolled in the study . Following scaling and root planing, patients were randomized to receive e ither 2% minocycline ointment or a matched vehicle control. Study medicatio n was administered directly into the periodontal pocket with a specially de signed, graduated, disposable applicator at baseline; week 2; and at months 1, 3, 6, 9, and 12. Scaling and root planing was repeated at months 6 and 12, Standard clinical variables (including probing depth and attachment lev el) were evaluated at baseline and at months 1, 3, 6, 9, 12, and 15. Microb iological sampling using DNA probes was done at baseline; at week 2; and at months 1, 3, 6, 9, 12, and 15, Results: Both treatment groups showed significant and clinically relevant r eductions in the numbers of each of the 7 microorganisms measured during th e entire 15-month study period. When differences were detected, sites treat ed with minocycline ointment always produced statistically significantly gr eater reductions than sites which received the vehicle control. For initial pockets greater than or equal to 5 mm, a mean reduction in probing depth o f 1,9 mm was seen in the test sites, versus 1.2 mm in the control sites. Si tes with a baseline probing depth greater than or equal to 7 mm and bleedin g index >2 showed an average of 2.5 mm reduction with minocycline versus 1. 5 mm with the vehicle. Gains in attachment (0.9 mm and 1.1 mm) were observe d in minocycline-treated sites, with baseline probing depth greater than or equal to 5 mm and greater than or equal to 7 mm, respectively, compared wi th 0.5 mm and 0.7 mm gain at control sites. Subgingival administration of m inocycline ointment was well tolerated. Conclusions: Overall, the results demonstrate that repeated subgingival adm inistration of minocycline ointment in the treatment of adult periodontitis is safe and leads to significant adjunctive improvement after subgingival instrumentation in both clinical and microbiologic variables over a 15-mont h period.