Design Of Wearing Experiment System For Tooth Hard Tissue Material

Wearing movement is a common phenomenon in the oral cavity, including the wearing between the teeth, the wearing between tooth restorative materials and the wear of toothpaste or brush during teeth-brushing and so on. Research on wearing of dental hard tissue or repair materials, can provide a theoretical basis for the development of wear-resistant tooth materials and preventing or delaying tooth wear. Because of many uncontrollable factors in the oral cavity, it is difficult to conduct wear test in human body while most researches have to be done in wear testing machine.Based on the cooperation with Department of Prosthodontics of Nineth People's Hospital in Shanghai Jiao Tong University School of Medicine, and Shanghai Key Laboratory of Stomatology, a wearing-test machine for dental hard tissue material is developed which provides an experimental method for developing dental hard tissue materials abrasion experiment.This project presents two methods for simulating the occluding process with the cam mechanism or eccentric disk mechanism for researching the wear of the teeth hard tissue. Each system includes wearing movement device, electrical driving system and occluding force detection system.The first method achieves relative wear movement between tooth materials under the stabile vertical force and the horizontal displacement driven by eccentric mechanism. In the second method, the wear device can simulate the chewing action in which there are both vertical occlusive force and a horizontal relative displacement between the teeth, and the chewing action is simulated by a combined cam contour with cubic multinomial and Sinusoid.The wearing device is driven by a frequency-conversion AC motor which rotate speed can be adjusted on line, so the chewing frequency is adjustable. In order to provide the function to set the wearing degrees, display the times and shut down automatically when the count down is reached, a relevant control system is developed based on the PLC.In the wearing experiment machine, the chewing force can be observed by detecting the vertical occlusive force with a force sensor, the data collecting systems and the recording instruments.On the basis of the wearing machine, the wearing test of dental hard tissue materials is done, and the wearing machine is verified which has been on the Application in Department of Prosthodontics of Nineth People's Hospital in Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology.