Public Release: 

Researchers are studying photodynamic therapy

American Academy of Periodontology

CHICAGO (November 11, 2004) - As the scientific community is seeking alternatives to antibiotic treatment, periodontal researchers found that photodynamic therapy (PDT) is advantageous for suppressing anaerobic bacteria that lead to periodontal diseases according to a recent study in the Journal of Periodontology.

"Although this study is still in its early phase, with the recent number of reports about bacterial strains becoming resistant to frequent doses of antibiotics, PDT could be an alternative to conventional periodontal therapeutic methods," said Michael P. Rethman, D.D.S., M.S., and president of the American Academy of Periodontology. "Antibiotics may be used as an adjunctive therapy for periodontal diseases, so there is a pronounced interest in the development of alternative antimicrobial concepts.

PDT involves two stages. In the first stage, a light-sensitive drug is applied. The second stage involves shining a light or laser directly on the area treated with the drug. When the light is combined with the drug, phototoxic reactions are induced which destroy bacterial cells. PDT was first approved by the Food and Drug Administration in 1999 to treat pre-cancerous skin lesions of the face or scalp.

In this study, researchers investigated anaerobic bacterial strains (bacteria that can only survive and grow in the absence of molecular oxygen) and facultative anaerobic bacteria (bacteria that can survive without oxygen).

"The photosensitizers we investigated were able to completely suppress the anaerobic key pathogens leading to periodontal diseases; however, facultative anaerobic bacteria tested responded to a lesser extent to PDT," said Dr. Bernd W. Sigusch, Friedrich Schiller University of Jena, Conservative Dentistry; Germany.

To specifically address the periodontal pockets in the body, the test tube results are presently being verified in several animal and human experiments.

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A referral to a periodontist in your area is available by calling 800-FLOSS-EM or visiting the AAP's Web site at www.perio.org. The American Academy of Periodontology is an 8,000-member association of dental professionals specializing in the prevention, diagnosis and treatment of diseases affecting the gums and supporting structures of the teeth and in the placement and maintenance of dental implants. Periodontics is one of nine dental specialties recognized by the American Dental Association.

EDITOR'S NOTE: A copy of the study "Killing Periodontopathogenic Bacteria by Photodynamic Therapy" is available to the media by contacting the AAP Public Affairs Department at 312-573-3243. The public and/or non-AAP members can view a study abstract online, and the full-text of the study may be accessed online for $20.00 at www.perio.org.

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