Experimental Investigation And Numerical Simulation Of Cutting Force-thermal Coupled Analysis Of Enamel And Dental Ceramics In Tooth Preparation

Tooth preparation and high-speed resurfacing of ceramic restorations are the keylinks in clinical dental surgery; the grinding heat/force and the coupled relationshipare the principal factors when grinding using dental handpiece, which also affect thedental patient’s clinical experience. With the subsidy of the National Natural ScienceFoundation, this dissertation investigated the above key issues. The main researchcontents and results are listed as follows:1. In the experiment of high-speed resurfacing, the performance of air-turbineand electric handpiece, together with the effect of coolant water weresystematically investigated in the in vitro apparatus. The results showed thatthe grinding parameter, direction and coolant water were the central factors indental resurfacing. Besides, based on the experimental results, rationalgrinding parameters were given in intraoral surgery.2. The grinding temperature platform of human molar had been put up, on whichsurface temperature of enamel was tested by using air-turbine handpiece. Theresults showed that coolant water could reduce the surface temperature,besides the grinding depth and direction had an obvious effect on the surfacetemperature, and the depth of grinding had greater influence on it than thefeedrate. Those conclusions had significant reference values in dental surgery.3. The solid mode of molar was rebuilt firstly by reverse engineering usingGeomagic Studio considering the free curved surface and the hierarchicalstructure of tooth; also pulp chamber was made to simulate the temperaturefield distribution. Grinding force-thermal coupled analysis was given byvirtue of FEA software Abaqus and the reliability of the model was verifiedby Fourier theorem of heat transmission. The results showed that stressconcentration existed in the concavity of enamel and thermal stress was largerin the juncture of enamel and dentine.The above research results have provided important theoretical basis and positivesignificance for resurfacing of ceramic restorations and tooth preparation in clinicaldental surgery.