高分解能6自由度運動測定器の開発

抄録

The pursuit of ideal occlusal contact is one of the fundamental objectives of the dental prosthesis. To attain this objective, the study on micro tooth movement is significant as well as the study on jaw movement. The purpose of this study was to evaluate a newly-developed extraordinary accurate motion detector that measures tooth movement in six-degree-of-freedom. The principle of the measurement is to detect magnetic field changes induced by Helmholtz coils. A right maxillary first premolar of an adult male volunteer was selected for the measurement. The tooth movement during buccal and palatal cusps loading was measured as the relative position changes to the opposite side maxillary first premolar. The results were as follows:
1. An extraordinary accurate motion detector that can evaluate tooth movement in six-degree-offreedom was developed. The resolution of the measuring system is 4 μm for translation and 0.0004°for rotation.
2. Under 23 kgf buccal cusp loading, the tooth was moved in the buccomedioapical direction. This movement ranged from 143 to 366 μm. Under palatal cusp loading, the tooth was moved in the palatoapical direction, ranging from 71 to 231 μm.