A clinical study of the number of occlusal tooth contacts in the intercuspal position at light and hard pressure in adults.

Young adults and Adults were investigated with respect to the number of occlusal tooth contacts. In the habitual intercuspal position (centric occlusion) there was, on a highly significant level, a smaller number of tooth contacts at light pressure than at hard pressure. When Young adults were compared with Adults there was a significantly smaller number of contacts at light pressure in the Adults. During hard pressure, there was no significant difference between the groups. There was no significant difference in the number of tooth contacts at light and hard pressure between patients referred for orthodontic treatment and others. In the group of Young adults, approximately 5% of the contacts appeared on a restoration at light pressure, while approximately 10% did so at hard pressure. There was no significant difference between those with and without contacts on a restoration with respect to the number of contacts at light and hard pressure. If the number of contacts on study casts of 106 adults (Adults-A), after occlusal adjustment in an articulator, was compared with the number of hard pressure contacts found clinically in thirty-five of them, no significant difference was found.