Researchers in Brazil have successfully tested photodynamic therapy (PDT) in rats and found that the treatment is effective at killing bacteria responsible for periodontal disease (or gum disease), an inflammation and infection of the gums, bones and tissue surrounding the teeth. Photodynamic therapy has been approved by the U.S. Food and Drug Administration to treat symptoms of esophageal cancer and non-small cell lung cancer. It has also been used to treat precancerous skin lesions.

In a study published in the March issue of the Journal of Periodontology, researchers from Sao Paulo State University found that rats given the new therapy had less inflammation and loss of alveolar bone and other periodontal tissue than rats not given the treatment.

Researchers simulated periodontal disease in the rats by placing ligatures at the first mandibular molars of each. The rats were divided into four groups with each receiving a different treatment or nothing at all. The PDT involves two stages. In the first stage, a light-sensitive drug is applied to the infected gum tissue. The second stage involves shining a laser or light at the area. Bacteria cells are then destroy as part of the phototoxic reaction created by the drug and laser. X-rays were taken 5, 15 and 30 days after the treatment to measure bone loss around the affected tooth.

Traditional treatment methods for periodontal disease include root scaling and planing -- a process that involves deep cleaning (debridement) of the tooth's surface above and below the gum line to remove hard tartar deposits. Dentists and periodontists also may prescribe antimicrobial medications (antibiotics) to control or prevent bacteria buildup. However, continued use of these drugs contributes to antibiotic resistance -- a global problem in the fight against disease and infection. Severe cases of periodontal disease may require gum surgery.

"We found that PDT is significantly less invasive than other treatments for periodontal diseases," Dr. Valdir Gouveia Garcia, the study's author, said in a press release. "It can provide improved dentin hypersensitivity, reduced inflammation of the tissues surrounding the teeth, and allows tissues to repair faster."

Added Dr. Preston D. Miller, president of the American Academy of Periodontology: "PDT may be an effective therapy for the treatment of periodontal diseases. While patients have many options for treating their periodontal diseases, PDT could prove to be a preferable alternative to antibiotic therapy. Unfortunately, long term antibiotic therapy not only decreases the drug's effectiveness, but also may lead to the development of drug resistant organisms."

Copyright 2007 iVillage Total Health.