The Experimental Study On PMMA Artificial Tooth To Improve The Hardness And Antiwear With Nanotechnology

Objective:To discover an effective way to enhance the wear-resisting ability of the artificial tooth by filling some nanometer matter, for providing the reference and foundation for further study in denture materials.Methods:l.The SiO2 and CaCO3 nanometer particles were observed by high-multiple optical microscope after having been diffused in MMA separately by hand or mechanical devices (stirring continuously or not) . We compared both groups of the data and analyzed the results with statistic method. (P>0.05)2.Filling the SiCh nanometer particles and CaCOs nanometer particles into MMA in different concentrations by mechanically stirring( continuously), then mix the liquid with PMMA powder in a certain proportion in order to get the standard samples. The mechanical performances including hardness, antiwear , bending strength and tension strength were tested. Then we analyzed the data with statistical method and compared them with pertinent literatures.Result s:l.The grains of nanometer SiCVMMA prepared by the three methods are larger than 200nm. The effects of three ways of diffusion had no significant difference by analyzing the variant data obtained from the mechanical tests including bending strength and tension strength of SiCVPMMA compound material (P>0.05) .2.There were no significant differences between the groups of SiO2/PMMA and CaCO3/PMMA(P>0.05), but significant differences were found in' each group(P<0.05). The increase of hardness of SiCVPMMA has no significant differences with the antitheses when the concentration of nanometer is 0.25% (P<0.05). With the increasing of concentration, there were significant differences between the samples which concentration of nanometer were0.5% , 0.75%, 1%, 2%> 3%, 4% (P<0.05), and got to the top at the concentration of 3%,thendeclined. The antiwear ability has no significant differences with the antitheses when the concentration of nanometer is 0.25 % and 0.5%(P<0.05). With the increasing of concentration, there were significant differences between the samples which concentration of nanometer were 0.75% , 1%, 2%, 3%, 4% (P<0.05), and got to the top at the concentration of 3%,then declined. The increase of hardness of CaCCVPMMA has no significant differences with the antitheses when the concentration of nanometer is 0.25% (P<0.05). With the increasing of concentration, there were significant differences between the samples which concentration of nanometer were0.5% ?0.75%, 1% (P<0.05).3. The bending strength and tension strength had no significant differences with the antitheses when the concentration of nanometer is 0.25%(P>0.05). There are significant differences between the samples which concentration of nanometer particles are 0.50%, 0.75%> 1% and the samples of the antitheses (P>0.05)in the two performances. There was a peak at the concentration of 0.50% ,then declined.Conclusions:1. It can'be used as a method to diffuse the nanometer SiO2 particles in MMA either by mechanical devices or by hand, but how to prevent the accumulation of the nanometer grains still need further study.2.Either filling MMA with nanometer SiO2 grains or nanometer CaCOa grains can increase the hardness and antiwear of the artificial tooth. The hardness and antiwear keep on increasing with the adding concentration of nanometer particles within the concentration range of this study.3. The bending strength and tension strength of the compound material can be improved by adding nanometer CaCO3 particles to MMA.