Proper diagnosis is the key for successful treatment. The conventional periodontal diagnostic techniques are based mainly on clinical parameters like, probing depth, clinical attachment level and dental radiographs. The major drawback of these conventional diagnostic aids is their inability to detect disease activity. Hence, new diagnostic aids were developed to overcome the deficiencies of the conventional diagnostic aids, they are termed under Advanced diagnostic aids. The main advantage of these aids over the conventional techniques is that they can detect the presence of active disease as well as predict future disease progression, and evaluate the response to periodontal therapy.