The initial lesion in the development of periodontitis is the inflammation of the gingival tissue in response to bacterial challenge. Attachment loss begins as an inflammatory change in the connective tissue wall of the gingival sulcus when the tissue loses its cohesiveness and detaches from the tooth surface. In current clinical practice, primarily used objective parameters to measure the tissue destruction are Probing pocket depth (PD), Clinical attachment level (CAL) and Relative attachment level (RAL). The assessment of CAL provides information relating to the loss or gain of connective tissue attachment to the root surface, and represent the standard by which clinicians record disease status. Though histological examination is the gold standard and periodontal probing is the most widely accepted method for measuring the amount of attachment loss, CAL remains the unsung hero in periodontal diagnosis.