[Analysis of occlusal contacts of children by the T-Scan system. (1) The reproducibility of the sensor].

The present study was designed to discuss the reproducibility and the clinical usage of the T-Scan system in children. A plastic model of a normal permanent dentition was used for the study. The model was pressed on the sensor of the T-Scan system in maximum intercuspation under various assigned pressures (10, 20, 30, 40 and 50 kg) which were controlled by a press machine (Auto Graph AG-5000C). The pressings were made under following conditions, such as 1) the sensor handle was fixed, 2) the sensor handle was free and 3) the sensor handle was free but the maxilla arch form was marked on the sensor by the silicone impressional material. The total number of tooth contacts were counted and sagittal and the vertical distance from midline to the tooth contacts were measured. The results obtained in the present study are summarized as follows: 1) The number of tooth contacts became stable, when the pressing sensor was exercised several times. 2) The more pressure raised on the sensor, the more the number of tooth contacts increased, and the more the coefficient of variation tended to decline. 3) The arch model displayed on the T-Scan system was not exactly represented in the actual dental arch. 4) Due to the marking by silicone impressional material on the sensor, the reproducibility of the T-Scan system was further improved.