Automated attachment level probing: effect of probing force

An automated electromechanical probe has been developed and fabricated which measures the distance from the bottom of the periodontal pocket to a fixed anatomical landmark on the tooth. The probe tip is extended into the pocket under controlled force and refracted automatically when the base of the pocket is reached. Position and acceleration time histories are analyzed to determine attachment level and pocket depth. The instrument was tested for its repeatability and bias in beagle dogs. Measurements were taken using either 25 or 35 gm of force. Bias was significantly reduced when 35 gm was used. The mean accuracy of the instrument using 35-gm force was 0.18 mm and included components of repeatability and bias.<>