It has been reported that regular maintenance of subjects with treated periodontal disease is the key consideration in the long-term periodontal prognosis of these subjects. Periodic prophylaxis may prevent loss of clinical attachment over long periods of time even in patients with less than optimal plaque control. However, there are limitations in routine subgingival re-instrumentation especially in bleeding pockets, as only 50% of these sites improve. Furthermore, the persistence of bleeding pockets increases the risk of disease progression and tooth loss. Thus there is a need for adjuncts that may improve the outcome especially in subjects with recurrent periodontitis during SPT. Some studies reported significantly better results with subgingival administration of local minocycline in residual pockets post initial periodontal therapy over a short period of time. There are few studies assessing the efficacy of topical minocycline gel in subjects with recurrent periodontitis while in SPT, and the long term effect.~The present study will examine the significance of the adjunctive effect of the subgingival application of a 2% minocycline hydrochloride controlled-delivery system (MHS) in comparison to subgingival instrumentation with application of a placebo gel, 3 months after therapy in subjects with recurrent periodontitis undergoing supportive periodontal therapy (SPT) and to assess the substantivity of the gel attributable to the adjunctive delivery of the medication that will be detected at 3 months during a 9-month period of regular SPT.
The aims of the present study are to assess the significance of the adjunctive effect of the subgingival application of a 2% minocycline hydrochloride controlled-delivery system (MHS) in comparison to subgingival instrumentation with application of a placebo gel, 3 months after therapy in subjects with recurrent periodontitis undergoing supportive periodontal therapy (SPT) and to assess the substantivity of the gel attributable to the adjunctive delivery of the medication that is detected at 3 months during a 9-month period of regular SPT. Recurrent periodontitis will be defined as sites with residual periodontal probing depths and bleeding on probing after completion of initial periodontal therapy. This will include both persistent and recurrent periodontitis, where persistent means the residual periodontal site after initial periodontal therapy, and recurrent means the site which was improved by initial periodontal therapy, but disease recurred.