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Microbial Associations in Periodontal Health and Disease

This study has been completed.
National Institute of Dental and Craniofacial Research (NIDCR)
Information provided by:
The Forsyth Institute Identifier:
First received: August 1, 2003
Last updated: November 8, 2010
Last verified: November 2010
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 Intervention Phase
Periodontal Diseases
Drug: metronidazole
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: Double Blind (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

Resource links provided by NLM:

Further study details as provided by The Forsyth Institute:

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

Enrollment: 154
Study Start Date: December 2002
Study Completion Date: December 2009
Primary Completion Date: December 2007 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
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

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.

Ages Eligible for Study:   35 Years and older   (Adult, Senior)
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
  Contacts and Locations
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Please refer to this study by its identifier: NCT00066001

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)
Principal Investigator: Ann Haffajee Boston, MA
  More Information

Responsible Party: Ann D. Haffajee/PI/Chair Department of Periodontology/Senior Member of the Staff, The Forsyth Instititute Identifier: NCT00066001     History of Changes
Other Study ID Numbers: NIDCR-12108
R01DE012108 ( US NIH Grant/Contract Award Number )
Study First Received: August 1, 2003
Last Updated: November 8, 2010

Additional relevant MeSH terms:
Periodontal Diseases
Gingival Diseases
Mouth Diseases
Stomatognathic Diseases
Anti-Infective Agents
Antiprotozoal Agents
Antiparasitic Agents processed this record on April 28, 2017