Jeffcoat MK, Jeffcoat RL, Jens SC and Captain K: A ttew periodontal probe with automated cemento-enamel junction detection. J Clin Periodontol 1986; 13: 276-280. Abstract. A new automated periodontal probe has been developed which measures attachment level relative to the cemento-enamel junction in a single measurement. The probe tip automatically enters the periodontal pocket and retracts under controlled force. As the probe tip transverses the cemento-enurnel junction, the electronics detect an alteration in the acceleration of the probe tip. Thus, the location of the cemento-enamel junction is determined automatically. The repeatability and accuracy of the probe was assessed in vitro. Measurements of attachment level were repeatable to 0.03 mm, and the probe had a net accuracy of 0.04 mrn.