The Experimental Study Of Different Processing Method For Transverse Strength Of Denture Base Resins

IntroductionPmma base resins is always widely used because it has good physics and chemistry, the machinery and the biology performance, and easy to be processed and so on, and heat polymerization is its solidification process and indispensable step.In this experimental, multi - purpose testing machine survey the transverse strength of polymethyl methacrylate resin by three struts law, through microwave processing, both water bath processing, the electrothermal treatment, as well as each method for two kind of different factories materials processing , comparison of transverse strength provides the model for the clinical work to choice better material and the processing method.Material and Methods1 By 30mm to be long, the 8mm width, the 2.5mm thick metal mold, and manufactures 96 wax molds using the metal mold, stochastically divides into 8 groups, each group of 12. Soaks wax molds in the water and preservates at the room temperature till measured.2. Pair of groups wax molds is processed by two kind of water baths heat treatments, microwave processing, electrothermal treatment in turn.3. After desflasking, one aspect of the test sample is ground smoothly, the other aspect polisheed, with the Vernier caliper definite test sample size till relative both sides parallel when the test sample size is controled, thickness between 2.20 0.10mm, Soaks the test sample in the water and preservates at the roomtemperature till measured.4. Survey each test sample, three times respectively, and record the averaging value5. Put the test sample in on the multi - purpose testing machine to measure the transverse strength with three struts law, the span is 24mm, the load speed is 5mm/Min, record each test sample break strength value as well as the stress- strain curve, calculates the test sample the transverse strength.6 .2 - ANOVA was performed to compare the results with spssl2.0.ResultsTransverse strength of different material with the identical method has the remarkable difference, transverse strength of the Shanghai Shanhu chemical plant production is smaller than that of the denture base resin of Heraeus Kulzer dental faculty limited company. For the identical kind of material, transverse strength of the microwave processing test sample does not have statistics difference from the water - bath battery and the electric heating group In 2 - 2 comparisons , the electric heating group has the remarkable difference with one kind of water water — bath battery, there is no remarkable differences in other 2-2 comparisons.DiscussionPolymethyl acrylic acid methyl resins is clinically widespread used, heating in water bath is its commonly used solidification way, but because its process time long, bad working conditions, inferior shortcomings urges us to attempt other effective methods. The transverse strength is important machine capability of denture base resins. This experiment has tested transverse strength of test sample processed by two kind of water baths methods, the microwave heating, the e-lectrothermics processing, the comparison with water bath method to evaluate the microwave heating, the electrothermics , carry on the preliminary judgment,____ 1____microwave - processing method has not remarkable difference with two kind of heating in water bath method and the electric heating method, microwave -processing method can evenly complete cure the material Evenly . The temperature elevates internally in flask Microwave is quite clean, the equipment is simple , further study may applicated. the electric heating group has the remarkable difference with one kind of Slowly heating up water - bath battery, there is no remarkable differences in other 2-2 comparisons. The electrothermal treatment method has good quality of cleaness, the energy conservation, and the time are short, the deep step of research should be conducted . Transverse strength of different material with the identical method has the remarkable difference, transverse strength of the Shanghai Shanhu chemical plant production is smaller than of the denture base resin of Heraeus Kulzer dental faculty limited company, in our clinical practice, we may select better denture base resins if the condition is to be possible.Conclusion1. Transverse strength of different material with the identical method has the remarkable difference2. The electric heating group has the remarkable difference with one kind of Slowly heating up water - bath battery, having the significant difference with rapidly heating up water - bath battery and microwave solidification.