Study Status: Completed
Recruit Status: Completed
Study Type: Interventional
Official Title: A Randomized Controlled Trial: Photodynamic Treatment for the Therapy of Premalignant Mucosal Oral Lesions.
Brief Summary: Pre-malignant lesions are difficult to treat. Even after surgical removal they tend to re-appear. Often the lesions are to large and are apparent on many sites, therefore surgical removal is not always possible. The photodynamic therapy uses a special substance, which is absorbed in cells, and thereafter activated by a defined light. The aim of this study is to compare the photodynamic therapy in potentially malignant lesions to a placebo. The investigators assume a significant better result in photodynamic therapy then treatment with a placebo.