【作者】 顾斌；

【导师】 马轩祥；

【作者基本信息】 中国人民解放军第四军医大学 ， 口腔临床医学， 2003， 硕士

【摘要】 模型的精度是各类义齿质量的重要保证。只有使工作模型精确再现口腔组织关系，才可能制作出与牙体密合、与口腔组织相适合的高质量的义齿。模型的消毒涉及到口腔医疗工作的安全性，我国有一亿乙肝病毒携带者，从患者口内取出的印模很可能被含有病毒的唾液、血液污染，而未经消毒处理的模型会造成院内交叉感染。 目前，口腔印模材料(藻酸盐)和模型材料(石膏)发展日趋成熟，为临床应用提供了可靠保证。而国内在工作模型制备过程中常见的一些不规范操作，如藻酸盐印模材料和超硬石膏调拌的水粉比例控制不严格、印模灌注模型前的放置时间过长、印模消毒处理不当等因素往往影响模型的质量，造成义齿精确性的降低。 本实验调查了临床上调拌藻酸盐印模和超硬石膏的水粉比的状况；检验了五种常用消毒方法在不同作用时间下对藻酸盐印模表面的HbsAg灭活效果，并从中选出三种有效的方法。然后分别将印模材料、超硬石膏调拌时的水粉比例、印模放置时间、印模消毒方法等因素作为实验变量条件，翻制了下颌牙列金属阳模的石膏模型。用测量显微镜测量了模型上设定的标志线段的长度变化，探讨了上述临床技术操作因素对模型精度的影响因素。经初步研究得出了以下结论： 1．藻酸盐印模料调拌的水粉比和印模放置时间对模型精度的影响。结果表明：①临床印模制备过程中，不注意标准化操作，仅凭经验调和使用印模料，对模型精度有很大影响。②印模料的水粉比应控制在23g：10g至30g：10g范围内，超出此范围印模极易变形。③印模放置15min和30min时出现显著性收缩性变形(P＜0.05)。 2．常用消毒方法灭活藻酸盐印模表面HBsAg的效果及其对印模精度 第四军医大学硕士学位论文的影响。本实验显示：①藻酸盐印模表面HBSAg经五种常用消毒方法消毒结果：浓度为 1500mg几的 NaC10消毒液浸泡消毒 10min或喷涂消毒 25min、2％中性强化戊二醛消毒液浸泡消毒 40mi n三种消毒方法均可完全灭活Hb sAg；2％中性强化戊二醛喷涂消毒60min灭活HBsAs效果不可靠；而臭氧消毒60min对HBsAg无效。②以上三种有效的消毒方法对藻酸盐印模精度的影响：浓度为1500mg／二的NaC10消毒液浸泡消毒10－30min对印模精度无明显影响；喷涂消毒45min时，出现显著性形变（P＜0．05入 2％戊二醛悄毒液浸泡处理 50而n、60Mn时，印模出现显著性形变（p＜0．05人③建议使用的藻酸盐印模消毒方法：1500mg几 的NaC10消毒液浸泡消毒10－30min、1500mg几的NaC10消毒液喷涂消毒25－35min或2％戊二醛消毒液浸泡处理40m工n。 3．超硬石膏调拌的水粉比对模型精度及其表面硬度的影响。结果表明：①当调拌超硬石膏的水粉比由 229人 变为 259：1009时，对模型精度无显著影响。②当超硬石膏的水粉比增大为259：1009时，模型的表面硬度出现显著性的降低（P＜0．05人更多还原

【Abstract】 The accuracy of models and dies are the foundation of various prosthetics. The casts poured from the impressions should be the exact replicas of the oral structures to ensure the fit of dentures to abutments and oral tissues. On the other hand, the disinfection of alginate is related to the safety of medical treatment. There are one hundred million HBV carriers in China, and the impressions are often contaminated with saliva and blood containing HBV. Consequently, working models become a potential source of contamination to cause cross infection.Nowadays, conventional impression materials (alginate) and model materials (dental stone) are well developed to ensure the qualities of model. However, these materials are usually not used correctly according to the directions of manufacture in clinic such as improper disinfection means and wrong W/P ratio of alginate and die stone. These problems reduce the accuracy of models and result in the failure of some dentures .This study investigated the practical W/P ratios of alginate and die stone that used in clinic, evaluated the antivirus effects of five methods that often used to disinfect impressions and chose good means. Then a mandible metal full arch was used as a master model, with four marks on it to represent two canine teeth and two first molar concavities. Some alginate impressions and die stone models were made in different conditions according to the W/P ratios and disinfections separately. Then the lines between the marks onstones models were measured and compared.1 The effect of water/power ratio and pouring time on accuracy and dimensional stability of alginate impressions. Study show that: (1)to mix alginate materials with the W/P ratio at will affects the accuracy of models greatly. (2)the W/P ratio of alginate material should be in the range from 23g:10g to 30g:10g , or the impression will deformation.(3)the time of pouring(15min and 30min) generated negative dimensional shrink(P<0.01).2 The effect of different disinfectant methods to alginate impression and dimensional changes after disinfection. Study show that: (1)HBsAg can be inactived by these means: a 10min soak in 1500mg/L sodium hypochlorite or 25 min wait after spraying of impression with this solution; a lOmin immersion in 2% glutaraldehyde. While these means have not effect: a 60min immersion in 2% glutaraldehyde or placing in ozone for 60min.(2)these measure will affect the accuracy of impression(P<0.05): immersing impressions in 2% glutaraldehyde for 50min and 60min;wait 45min after spraying of impression with 1500mg/L sodium hypochlorite.(3)these means have good and virus effected and don’t change the accuracy of impression: a 10-30min soak in 1500mg/L sodium hypochlorite or 25-35 min wait after spraying of impression with this solution; a 40min immersion in 2% glutaraldehyde.3 The effect of water/power ratio on accuracy and hardness of alginate impressions. Study show that:(1)the water/power ratio of mixing die stone changed from 22g:100g to 25:100g doesn’t affect the accuracy of models. (2) The surface hardness and abrasion resistance of models decreased greatly when the W/P ratio of mixing die stone changed from 22g:100g to 25:100g(P<0.05).更多还原