Development of the measuring system of 3-D force on the tooth and Measurement to an abutment tooth of the partial denture

本研究的目的是利用一种特殊的微型压电式压力传感器，研究基牙在活体上的三维力的形态。为了弄清小型压电式载荷传感器的特性，研制了一种钢材刚性校对装置，它不具有0.05°角度变化的1轴可变副。这使得能够加载到用黄铜夹具固定的传感器上，从水平方向到垂直方向。当传感器输出与已知载荷之间进行回归分析时，X轴、Y轴和Z轴的相关系数分别为0.99999、0.99999和0.99996。迟滞对传感器输出的最大影响在X轴、Y轴和Z轴分别为0.9%、1.1%和1.7%。由于温度对传感器输出的影响以10度上升来考察，X轴、Y轴和Z轴上的输出分别增加了0.5%、0.46%、…更多的分别。结果表明，该传感器具有较高的精度，适用于活体测量牙齿上的功能载荷。研制了一种由类似金属芯体的内侧部分、力传感器和类似牙冠的外部部分组成的载荷测量装置。它们用钢丝钉连接在一起，并用临时粘固剂固定在牙齿上，因此它能够在活体上测量牙齿上的载荷。在解释了这项研究的目的后，获得了受试者的知情同意。咬合过程中记录牙冠受力的大小和方向。在自然牙列中，随着咬合力的增加，近中腭侧载荷方向发生变化。对于有活动牙托的部分义齿的基牙，当有咬合支托时，载荷的大小大于无牙托时的载荷，且载荷方向在远中颊侧发生变化。结论：该系统能够在体内测量基牙的三维功能载荷。较少

The aim of this study was to investigate the modality of 3-D force onto abutment tooth in vivo with a special miniaturized piezo-electric force transducerIn order to clarify the characteristic of a small crystal piezo-electricity formula load sensor, a rigid proofreading equipment, made with steel material, that hate 1 axis variable vice of angle change by 0.05-degree was developed. This was enable to load to the transducer fixed with a brass jig from horizontal direction to vertical direction. When regression analysis between sensor output and the known amount of loads was applied to investigate the linearity, correlation coefficients of X-axis, Y-axis and Z-axis are 0.99999, 0.99999 and 0.99996, respectively. The effect of the hysteresis on sensor output for X-axis, Y-axis and Z-axis were 0.9%, 1.1% and 1.7% at the maximum, respectively. As the effect of temperature on sensor output was examined by 10-degree rise, the increase of output on X-axis, Y-axis, and Z-axis were 0.5%, 0.46%, … More respectively. These results showed the transducer hadquite precision, and was suitable for in vivo measurement of functional loads onto the tooth.A load measuring device that consists of an inner part similar to a metal core, a force transducer and an outer part similar to a tooth crown was manufactured. These were united by a steel screw and set with temporary cement on the tooth, so it enabled to measure the load onto the tooth in vivo.Informed consent was obtained from subjects after explaining the aim of this study. During clenching, force magnitudes and directions in 3-D on tooth crown were recorded. When the bite force increased, the direction of load changed in the mesial palate side in natural dentition. For the abutment tooth of a partial denture which have a removable occlusal rest, when with the occlusal rest, the amount of load became lager than not with the occlusal rest and the direction of load changed in the distal buccal side.Conclusion : this system enables to measure a 3-D functional load onto abutment tooth in vivo. Less