Common Antibiotic Halts Progression of Gum Disease, Puts It In "Holding Pattern"

BUFFALO, N.Y. -- A multi-center study has shown that daily low doses of a common antibiotic can halt the progression of adult periodontal disease.

Sebastian G. Ciancio, D.D.S., professor and chair of the University at Buffalo Department of Periodontology, said the 12-month clinical trial showed that 20 milligrams of the antibiotic doxycycline taken twice a day can stop bone loss, gum detachment and bleeding of the gums in adults with periodontal disease.

Ciancio reported the results on March 21 at the annual meeting of the International Association for Dental Research in Orlando, Fla.

"We found that we can induce the disease to go into a holding pattern," said Ciancio. "The significance of this finding is that people who have no dental insurance or lose their dental insurance temporarily can keep their periodontal disease in check until they can afford treatment." The low dose of antibiotic did not induce bacterial resistance, he said.

In addition to the UB School of Dental Medicine, the trial involved researchers at Eastman Dental College, University of Oregon, West Virginia University, University of Florida, University of Missouri, UCLA, University of Michigan, University of Texas-San Antonio, University of California-San Francisco and State University of New York at Stony Brook.

The therapy's effectiveness derives not from the drug's anti-microbial action, Ciancio said, but from its ability to prevent the breakdown of collagen, the basic building block of all connective tissues. The results have implications for the treatment of many other diseases, including arthritis and some cancer, he said.

Ciancio and Lorne Golub, D.M.D., of Stony Brook, have been researching this pathway of action for more than a decade in collaborative studies between UB and Stony Brook.

The work dates to 1983, Golub said, when his group demonstrated for the first time that the tetracycline family of antibiotics could block the action of collagenase, a tissue-destructive enzyme. Persons with diabetes and other diseases involving tissue breakdown have elevated levels of the enzyme. Golub's group developed and patented the low-dose tetracycline, doxycycline, that was tested in the clinical trial.

The trial involved 436 adults with diagnosed periodontal disease. Subjects were placed randomly into four groups and assigned to receive a placebo or doxycycline for 12 months. The groups receiving the drug took 10 milligrams four times a day, 20 milligrams four times a day, or 20 milligrams twice a day.

Researchers monitored the status of disease symptoms in the full mouth every six months and at selected sites every three months. X-rays also were taken every six months.

The regimen of 20 mg., twice a day, was found to be most effective, Ciancio said. The participants in this group showed significant improvement in gum attachment level, the depth of pockets between teeth and gum, and bleeding of the gums, all symptoms of periodontal disease. This group also showed no increase in bone loss surrounding the teeth, which occurs as a result of the infection.

Bone loss increased and other symptoms progressed over the 12-month period in the placebo group.

The doses of antibiotics at this level did not generate resistance, results showed, an outcome that would have rendered this antibiotic and others in the same family ineffective in this group of people as a treatment for infection in the future. The treatment also didn't generate any adverse side effects.

Basic research on the action of doxycycline was supported by a grant from the National Institute of Dental Health. The clinical trial was supported by CollaGenex Pharmaceuticals, Inc.