纳米义齿基托树脂的制备及挠曲性能的研究

The preparation and flexural properties of Nano-denture base resin

目的在聚甲基丙烯酸甲酯粉（PMMA）中添加有机改性的蒙脱土制备纳米义齿基托树脂,以增强义齿基托树脂的挠曲性能。方法将蒙脱土经十六烷基三甲基溴化铵改性,形成有机化改性的蒙脱土,将其加入牙托粉中形成混和粉,混和粉与热凝牙托水调和后经加热固化形成纳米义齿基托树脂。用X射-线衍射（XRD）和透射电子显微镜（TEM）表征了固化后材料的结构,用三点挠曲试验测量固化后材料的挠曲强度和挠曲弹性模量。用一维方差分析法评价有机化蒙脱土的量对挠曲强度的挠曲弹性模量的影响。结果 XRD、TEM证实当蒙脱土在混合粉中的量为3%和5%时,蒙脱土在PMMA基质中形成部份剥离和插层结构;当蒙脱土在混合粉中的量为3%时,挠曲强度达最大,进一步增加蒙脱土的量,材料的挠曲强度降低。当混和粉中有机蒙脱土的量在1%~10%时,挠曲弹性模量随有机蒙脱土的量增加而增加。一维方差分析表明当混和粉中有机蒙脱土的量为3%时,实验组的挠曲强度与挠曲弹性模量均存在显著性差异（n=5,P〈0.05）。结论牙托粉中蒙脱土的量对义齿基托树脂的挠曲性能有显著性影响。

Objective The denture bases nanocomposites were prepared by adding organic montormollontrite（OMMT） into poly（methyl methacrylate） matrix.Methods The resulting composites were characterized by XRD,TEM and ISTRON 3365 flexural strength testing systems.One-way analysis of variance and Tukey＇s test were used to compare the difference in flexural strength and flexural modulus.Results The exfoliated-intercalated and intercalated denture base nanocmposite was formed when the content of OMMT was 3 wt % and 5 wt % in the powder of denture base resin,respectively.The maximum ultimate flexural strength was observed in denture base nanocomposite containing 3 wt% of OMMT and flexural strength decreased with further increases of OMMT content.The flexural modulus of denture base nanocomposite increased continually with OMMT content increasing from 1 wt% to 10 wt%.Significant difference in both flexural strength and flexural modulus was observed between the nanocomposites with 3 wt% organic montormollontrite and controls（n=5,P0.05）.Conclusions The content of organic montormollontrite in denture base powder effect significantly on the flexural properties of denture base resin.