含氯消毒剂对石膏模型消毒及变形影响的调查

目的 将含氯消毒剂调拌石膏灌注义齿石膏模型,评价对其模型表面杀菌效果及尺寸精度改变.方法 在临床用同等条件印取藻酸盐印模,分别用500 mg/L和1000 mg/L含氯消毒剂水溶液及自来水调拌石膏灌注石膏模型,其后对石膏模型表面相同的位置取样、接种、培养并进行CFU计数;在实验室用标准印模分别用500 mg/L和1000 mg/L含氯消毒剂水溶液及自来水调拌石膏粉进行灌注石膏模型,其后进行模型尺寸测量.结果 用含氯消毒剂调拌石膏灌注模型组和自来水调拌石膏灌注模型组表面细菌,加水石膏组(14.667±4.61)CFU/cm2,500 ml/L含氯消毒组(4.3±3.592)CFU/cm2,1000 ml/L含氯消毒组(2.2±1.989)CFU/cm2,差异有统计学意义(P＜0.01);分别用水和含氯消毒剂水溶液调拌石膏粉进行灌注模型尺寸测量,经SPSS软件分析长宽差异无统计学意义.结论 用含氯消毒剂水溶液调拌石膏粉进行灌注模型可达到消毒作用,并且不会使模型产生变形.     

微波消毒甲基丙烯酸树脂义齿的实验研究

目的 研究微波应用于甲基丙烯酸树脂基托义齿的消毒效果以及对义齿基托材料力学性能的影响.方法 选择40件常规制作完成的甲基丙烯酸树脂基托义齿,随机分成A、B、C、D 4组,每组10件,D组为对照组.将A、B、C、D组义齿放入装有200ml蒸馏水的烧杯中,A、B、C组分别经700 W功率微波照射3,4,5 min后分别进行取样细菌培养,以抑菌率评价消毒效果;通过万能实验机测试微波照射前后甲基丙烯酸树脂的弯曲强度和冲击强度,观察微波照射对甲基丙烯酸树脂的力学性能的影响.结果 700 W功率的微波照射4 min的抑菌率≥90%,5 min的抑菌率达100%;700 W功率照射5 min组甲基丙烯酸树脂的弯曲强度和冲击强度与对照组比较无显著差异.结论 700 W功率的微波照射5 min可以有效杀灭甲基丙烯酸树脂义齿表面的所有细菌,并对甲基丙烯酸树脂的弯曲强度和冲击强度无明显影响,可以用于甲基丙烯酸树脂基托义齿的消毒.

Abstract：

Objective The purpose of this study was to evaluate the disinfection effectiveness and properties of acrylic resin via microwave irradiation. Methods Forty acrylic resin base dentures fabricated in a standardized procedure were chosen and divided into Group A,B,C and D randomly. Group A,B and C were immersed in 200ml distilled water and submitted to microwave irradiation at 700W for 3,4,5 minutes individually. Group D was used as positive control. Bacteria specimens from each group were got for culture and numbers were calculated. Then the four groups were tested for the flexural strength and impact strength by universal test machine before and after microwave irradiation sterilization. Results The germicidal ratio of Group B was more than 90% ,while the ratio of group C was 100%. There was no significant difference in flexural strength and impact strength between group C and group D. Conclusions Microwave irradiation for 5 minutes at 700W produced sterilization of dentures contaminated with all bacteria whereas the denture strength is not affected. Microwave irradiation at 700W solution for 5 minutes was effective to sterilize acrylic resin base dentures.