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小型压电式力传感器，研究在体基牙三维力的形态，为明确小晶体压电式力传感器的特点，研制了一种刚性校对装置，该装置由钢制材料制成，可承受0.05 °角变化的单轴可变副。这使得能够从水平方向到垂直方向加载到用黄铜夹具固定的换能器。当传感器输出和已知负载量之间的回归分析应用于研究线性时，X轴、Y轴和Z轴的相关系数分别为0.99999、0.99999和0.99996。滞后对X轴、Y轴和Z轴传感器输出的影响最大分别为0.9%、1.1%和1.7%。当温度对传感器输出的影响通过10度上升来检验时，X轴、Y轴和Z轴上的输出增加分别为0.5%、0.46%、 ...更多信息 分别结果表明，该传感器具有较高的精度，适合于在体测量牙齿的功能载荷。通过钢螺钉将其连接起来，并在牙齿上临时固定骨水泥，因此能够测量活体牙齿上的负荷。在解释本研究目的后，获得受试者的知情同意。在咬合过程中，记录牙冠上三维力的大小和方向。在自然牙列状态下，随着咬合力的增加，载荷的方向向腭近中侧改变。对于有可摘支托的基牙，有支托时基牙所受的载荷大于无支托时基牙所受的载荷，且载荷方向发生了变化，主要分布在远中颊侧。结论：该系统能够在活体上测量基牙所受的三维功能载荷。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