Occlusion of full cast crown at the intercuspal position

The IP-Checker type MS capable of measuring the height of a crown at the intercuspal position (IP) was invented. The following observations were obtained. 1. The intercuspal position is stable within 5 micrometers. 2. The intercuspal positions shows a higher stability under slight biting than under heavy biting. Under this condition, the teeth show a displacement of about 20 micrometers by the distortion of the periodontal membrane. 3. The crown made by the ordinary procedure is about 30 micrometers higher at the intercuspal position. Therefore, an occlusal adjustment is always necessary. 4. With the current method of occlusal adjustment, adjustment of the crown to a definite height with the maximum error of 10 micrometers is possible in the oral cavity.