To promote root canal disinfection and debris removal and improve successful treatment we need effective irrigating solutions and proper instrumentations.The effective elimination of bacteria requires the initial cleaning of the canal by removal of the smear layer and the breakup of the biofilm leaving the bacteria accessible to the disinfecting agent .Materials which will remove the smear layer and or disturb the biofilm structure includes sodium hypochlorite ,EDTA, citric acid and photo activated disinfection process.