[Investigation on relationship between wedge-shaped defects and occlusal interference]

To investigate the relationship between wedge-shaped defects and occlusal interference.Following examination from 46 patients, a total of 157 teeth were identified to have the criteria set for wedge-shaped defects and regarded as the experiment group. Also, 157 adjacent teeth exhibiting no such noncarious cervical lesions were randomly selected from the same group of patients and regarded as the control group. The distribution of occlusal force and time were examined with T-Scan II system in 46 patients with wedge-shaped defects in intercuspal occlusion position, protrusive movement and lateral movement. Occlusal interference and premature contact were evaluated and compared between the two groups.The proportion of the teeth with premature contact in experiment group was 6.37%, while the control group was 2.55%, there was no significant difference between the two groups (P0.05). The total proportion with occlusal interferences in experiment group was 23.57%, which was significantly higher than that of the control group (10.19%, P0.05), in experiment group the proportion with working side interferences was 15.92%, and in control group, the proportion was 3.82%, there was significant difference between the two groups (P0.01). At the same time, the teeth with occlusal interferences had more serious degree of the wedge-shape defects than those with no occlusal interference.The increased occlusal force has relation to the formation as well as severity of wedge-shaped defects.