The prevalence of chronic periodontitis in the Brazilian population is very high. Periodontal diseases are infections, caused by specific groups of microorganisms and the goal of therapy is to suppress or eliminate the pathogenic species responsible for periodontal disease progression. Scaling and root planing (SRP), one of the most common forms of periodontal treatment, controls periodontal destruction in most cases but the results are not definitive. Recent studies carried out in our laboratories have shown that the addition of systemically administered metronidazole or weekly professional, supragingival plaque removal can enhance the beneficial effects of SRP. However, the effects of these adjunctive therapies alone or in combination have not been tested in Brazilian and untreated populations with advanced periodontal disease. The purpose of the present investigation is to evaluate the clinical and microbiological effects of SRP alone or in combination with systemically administered metronidazole, repeated professional cleaning, or both, in untreated subjects with chronic periodontitis from the Brazilian population. This research will be performed primarily in Brazil, at Guarulhos University, in collaboration with Dr. Magda Feres as an extension of NIH grant #DE12108. 60 subjects will be randomly assigned to 4 groups. The control group will receive SRP and a placebo. The 3 test groups (T1, T2 and T3) will receive: T1- SRP and 400 mg of systemically administered metronidazole tid for 10 days; T2 - SRP, weekly professional cleaning for 3 months and placebo; and T3 will receive SRP, metronidazole and professional cleaning. Subgingival plaque samples will be collected from 7 sites per subject at baseline and at 3, 6 and 12 months post-therapy. The presence of 40 subgingival species will be determined using DNA probes and Checkerboard DNA-DNA hybridization. Clinical measurements, including pocket depth, attachment level, bleeding on probing, presence of visible plaque and suppuration will be performed at 6 sites per tooth at baseline and 3, 6 and 12 months post-therapy. Significance of differences in each group over time will be determined using the Friedman test and differences among groups using the Kruskal Wallis test. The results will determine the clinical and microbiological effects of each therapy separately and if the combination of therapies leads to greater benefit. The differences between this study and the parent grant will be the ethnic background of the subjects, the level of periodontal disease and the dosage of metronidazole employed.

National Institute of Health (NIH)
Fogarty International Center (FIC)
Small Research Grants (R03)
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International and Cooperative Projects 1 Study Section (ICP)
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Sina, Barbara J
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Forsyth Institute
United States
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Feres, Magda; Teles, Flavia; Teles, Ricardo et al. (2016) The subgingival periodontal microbiota of the aging mouth. Periodontol 2000 72:30-53
Feres, Magda; Gursky, Lauren Christine; Faveri, Marcelo et al. (2009) Clinical and microbiological benefits of strict supragingival plaque control as part of the active phase of periodontal therapy. J Clin Periodontol 36:857-67
Faveri, Marcelo; Figueiredo, Luciene Cristina; Duarte, Poliana Mendes et al. (2009) Microbiological profile of untreated subjects with localized aggressive periodontitis. J Clin Periodontol 36:739-49
Matarazzo, Flavia; Figueiredo, Luciene Cristina; Cruz, Sergio Eduardo Braga et al. (2008) Clinical and microbiological benefits of systemic metronidazole and amoxicillin in the treatment of smokers with chronic periodontitis: a randomized placebo-controlled study. J Clin Periodontol 35:885-96