Photodynamic therapy (PDT) may be an effective treatment for certain bacterial infections of the oral cavity, including some that are resistant to antibiotics, research from the University at Buffalo's School of Dental Medicine has shown. Researchers found that the bacteria S. mutans, as well as fungal organisms of the genus Candida, were highly susceptible to killing with minimal doses of PDT, both in laboratory dishes and on biofilms grown on denture material. The findings were presented at the recent International Association of Dental Research meeting in Orlando, Florida. 'The results of the studies so far, while not completed, may have important implications in the treatment of oral infectious diseases currently confounding the medical and dental community,' said Thomas S. Mang, associate professor of oral and maxillofacial surgery and senior author on the study.

'PDT may provide an adjunct to current antibiotic treatment or an alternative where antibiotics no longer are working. This may be vital for patients undergoing cancer therapy, HIV patients who demonstrate resistance to antibiotics and the elderly with persistent oral infections.'

Photodynamic therapy is based on the propensity of certain types of cells or organisms to absorb light-sensitive drugs. This selective retention allows researchers to direct a laser beam into the organism, which activates the drug and kills the organism but does not damage surrounding tissue.