Effect of different occlusal forces on the accuracy of interocclusal records of loose teeth.

BACKGROUND: This study aimed at investigating the effect of loose teeth on the accuracy of occlusal records by comparing the differences in the number of occlusal contact points, occlusal contact area and the centre of the occlusal contact region under different occlusal forces in patients with periodontitis. OBJECTIVE: The effects of different occlusal forces on the occlusal contact point (OCP), occlusal contact area (OCA) and the centre of occlusal contact region (OCC) of loose teeth. METHODS: Occlusal training was performed on the 30 patients who completed periodontal serial treatment. One doctor took the occlusal records with silicone rubber and the T-scan system; the patients were digitally scanned intraorally by a technician. The data of the healthy teeth were recorded as the control group, and the data of the loose teeth were recorded as the experimental group. Then, we used Image J to measure the numbers of OCP and OCA and Auto CAD to calculate the coordinates of OCC. A paired t test was used to analyse whether the differences in OCP, OCA and OCC were statistically significant when the occlusal forces were different. RESULTS: The OCA of all three experimental methods increased under heavy occlusal force (p < .01), and the silicone rubber OCA increased the most. The OCC of all three experimental methods was shifted in the buccal and mesial (p < .01). And the occlusal records obtained by the T-scan system showed a low correlation between the differences of OCA and OCC. CONCLUSION: Whether the teeth were loose or not, the OCA increased under heavy occlusal forces. For patients with loose teeth, the OCC was shifted towards the buccal under heavy occlusal force.