The aim of the proposed study is to assess the clinical effect of photodynamic therapy (PDT)using LED on dentin with carious lesions in permanent teeth. Patients with molars exhibiting deep carious lesions on the occlusal surface indicated for restorative treatment will be randomly allocated to two groups: Group 1 -Control after incomplete caries removal,indirect pulp treatment with calcium hydroxide(CH); Group 2 - PDT + CH after incomplete caries removal,disinfect the residual dentin with PDT(LED + methylene),then indirect pulp treatment with CH. Dentin samples will be removed before and after PDT for microbiological analysis. The microbiological samples will be cultured in Brucella blood agar, Mitis Salivarius-bacitracin agar and Rogosa Selective Lactobacillus agar. The teeth will then be restored using resin with clinical and radiographic follow up at six, 12 and 24 months. The data will be submitted to descriptive statistics.