Slow release metronidazole and a simplified mechanical oral hygiene regimen in the control of chronic periodontitis.

The present study is one of a series aimed at devising practical methods of control of chronic periodontitis that do not depend upon stringent interdental cleaning by the patient. The regime consists of professional and home care components thought to be realistic for general practice. Patients with chronic periodontitis, but without any complicating factor, such as systemic disease, recent antimicrobial therapy or occlusal traumatism were selected. They received an initial thorough scaling, root planing and an instruction in Bass brushing, using a multituft brush and a sodium fluoride toothpaste, but without emphasis on inter-dental cleaning. They were then assigned to one of two groups, one of which received, in addition to the above mechanical oral hygiene regime, low (0.5%) and the other high (40%) dose metronidazole locally in periodontal pockets once a week for 4 weeks. The low dose was supplied in the form of solution inside fine dialysis tubing. The high dose was in the form of metronidazole powder incorporated in acrylic resin. Plaque index, sulcus bleeding index, probeable pocket depth and gingival shrinkage were monitored during this period and for a further 8 weeks. Both groups showed highly significant reductions in (supragingival) plaque and periodontal inflammation, maintained at least 8 weeks after the end of the 4-week chemotherapy period. Reductions in SBI were greatest for the 40% metronidazole group. It was concluded that local metronidazole, even in the form of 0.5% metronidazole in a small portion of dialysis tubing, has a positive rôle in the control of chronic periodontitis.