Photodynamic therapy may have a role in periodontitis

NEW YORK (Reuters Health) March 16 Photodynamic therapy (PDT) transiently reduces the progression of experimentally induced periodontal disease in rats, researchers from Brazil report in the March issue of the Journal of Periodontology.

In 120 Wistar rats, Dr. Valdir Gouveia Garcia from Sao Paulo State University and colleagues placed ligatures at the first mandibular molar to induce periodontal disease including accumulation of plaque, local bone loss, and inflammatory reactions.

They divided the rats into four groups of 30: no treatment (control); topical treatment with the photosensitizer methylene blue only; low level-laser therapy only; or a combination of methylene blue and low-intensity laser (the PDT group). The rats were sacrificed 5, 15 or 30 days postoperatively.

Radiographic results showed significantly less bone loss in the PDT group compared to the control group at 5 days postoperatively, the team reports. At 15 days, significantly reduced bone loss was seen in the PDT group compared with the control and low-laser therapy groups. At 30 days, however, there were no significant differences in bone loss in any of the groups.

Comparative histologic analysis revealed no statistically significant differences in the extent of inflammatory reaction in gingival tissue and alveolar bone resorption in any of the groups.

"Although the present study did not intend to treat periodontal disease but rather to evaluate PDT as a possible adjutant therapy, the results suggested that PDT transiently reduced periodontal tissue destruction," Dr. Garcia and colleagues write.

"This is an exciting finding," said Dr. Preston D. Miller, Jr., president of the American Academy of Periodontology, who was not involved in the research. "PDT could prove to be a preferable alternative to antibiotic therapy."

"Our Academy supports future research to further define the application of PDT as a means to treat periodontal disease," he added.

J Periodontol 2007;78:566-575.

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