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Microbial Associations in Periodontal Health and Disease

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00066001
Recruitment Status : Completed
First Posted : August 5, 2003
Last Update Posted : November 9, 2010
National Institute of Dental and Craniofacial Research (NIDCR)
Information provided by:
The Forsyth Institute

Brief Summary:
The purpose of this study is to determine the clinical and microbiological effects of systemically administered metronidazole alone or in combination with professional plaque removal on periodontally diseased patients.

Condition or disease Intervention/treatment Phase
Periodontitis Periodontal Diseases Drug: metronidazole Phase 2

Detailed Description:
Major goals of periodontal research are to differentiate pathogenic from host compatible plaque microbiotas and to optimize treatments to convert the former to the latter. To this end, in the previous award period the composition of supra and subgingival plaques, the associations among species both within and between supra and subgingival plaques, and differences between plaques from healthy and diseased individuals were determined. One major finding was the frequent detection of anaerobic periodontal pathogens at low numbers in supragingival plaque of periodontally diseased and to a lesser extent healthy subjects. Weekly professional supragingival plaque removal for 3 months in 18 periodontitis subjects demonstrated astonishing reductions in the subgingival microbiota which were maintained for 9 months after cessation of the professional program. The composition of the microbiota at 12 months in these subjects was similar to that found in periodontal health. In another of our studies, systemically administered metronidazole produced similar effects. Thus, in SA1 a 2 year randomized clinical trial will be performed comparing the effects of 1) SRP alone or in combination with 2) weekly professional supragingival plaque removal, 3) systemically administered metronidazole or 4) a combination of the 2 on clinical parameters and supra and subgingival plaque composition. 200 periodontitis patients will receive SRP under local anaesthesia and will be randomly assigned to the 4 treatment groups. All subjects will be evaluated clinically and for supra and subgingival plaque composition at 2 weeks, 3, 6, 12, 18 and 24 months. Supra and subgingival plaque samples will be taken separately from the mesial aspect of each tooth and evaluated individually for their content of 40 bacterial species using checkerboard DNA-DNA hybridization providing over 3.6 million bacterial counts. The results will determine if the beneficial effect of the individual therapies persist beyond one year and whether combined treatment produces even greater benefit to the patient.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 154 participants
Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: The Effect of Systemically Administered Metronidazole Alone and in Combination With Professional Supragingival Plaque Removal on Plaque Composition
Study Start Date : December 2002
Actual Primary Completion Date : December 2007
Actual Study Completion Date : December 2009

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Placebo Comparator: 1, 2, 3, 4
The 4 arms of the study are based on the treatment groups: 1. scaling and root planing alone (SRP); 2. SRP plus repeated professional supragingival plaque removal; 3. SRP + systemically administered metronidazole; 4. SRP + repeated professional supragingival plaque removal + systemically administered metronidazole.
Drug: metronidazole
antibiotic that is particularly effective against Gram negative bacterial species

Primary Outcome Measures :
  1. Change in mean attachment level [ Time Frame: Baseline, 3, 6 12 18 and 24 months ]

Information from the National Library of Medicine

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Ages Eligible for Study:   35 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No


  • > 35 years of age
  • > 20 teeth
  • > 5% sites (approx. 8 sites) with pocket depth > 4 mm and / or 5% sites with attachment level > 4 mm


  • > 50% of sites with pocket depth or attachment level > 4 mm
  • Pregnancy or lactation
  • Periodontal or antibiotic therapy in the previous 12 months
  • Any systemic condition which might influence the course of periodontal disease or treatment (e.g. diabetes, AIDS)
  • Any systemic condition which requires antibiotic coverage for routine periodontal procedures (e.g. heart conditions, joint replacements etc.)
  • Any known allergy to metronidazole

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00066001

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United States, Massachusetts
Department of Periodontology, The Forsyth Institute
Boston, Massachusetts, United States, 02115
Sponsors and Collaborators
The Forsyth Institute
National Institute of Dental and Craniofacial Research (NIDCR)
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Principal Investigator: Ann Haffajee Boston, MA
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Responsible Party: Ann D. Haffajee/PI/Chair Department of Periodontology/Senior Member of the Staff, The Forsyth Instititute Identifier: NCT00066001    
Other Study ID Numbers: NIDCR-12108
R01DE012108 ( U.S. NIH Grant/Contract )
First Posted: August 5, 2003    Key Record Dates
Last Update Posted: November 9, 2010
Last Verified: November 2010
Additional relevant MeSH terms:
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Periodontal Diseases
Mouth Diseases
Stomatognathic Diseases
Anti-Infective Agents
Anti-Bacterial Agents
Antiprotozoal Agents
Antiparasitic Agents