藻酸盐印模材料水粉比及印模放置时间对模型精度的影响

目的 :观察水粉比及印模放置时间对藻酸盐印模材制取全牙列模型精度的影响。方法 :制取一个标准下颌牙列金属母模。用 3种水粉比 ( 2 3∶10 ;30∶10 ;33∶10 )调拌藻酸盐印模材料 ,制取 30个模型 ,每组 10个。再用两种水粉比 ( 2 3∶10 ;30∶10 )各制取 30个印模 ,分别放置不同时间 ( 0、15、30min)灌制模型。用测量显微镜测量模型各标志点的距离 ,所得数据进行统计分析。结果 :①不同的水粉比制备印模 ,当水粉比为 33∶10时 ,66间线段长度的标准差异常增大 (s =0 .2 0 6) ,其余线段的长度变化无明显统计学意义 (P >0 .0 5 ) ;②随着放置时间的延长 ,印模出现收缩变形 ,统计有显著差异 (P <0 .0 1)。结论 :①适量增加水粉比 ,模型仍可获得较高的精度 ,但随着水粉比的增加 ,印模强度下降 ,容易变形 ;②随着放置时间的增加 ,印模收缩变形     

添加抗菌剂的藻酸盐印模材料抗菌性能的实验研究

目的：对分别添加磷酸锆载银抗菌剂,醋酸洗必泰,三氯新3种抗菌成分的藻酸盐印模材料的抗菌性能进行测试,为口腔抗菌印模材料的研制奠定实验基础。方法：以1％的添加比将3种抗菌成分加入藻酸盐印模材料中,采用薄膜密着法,分别测试添加抗菌成分后印模材料对金黄色葡萄球菌,大肠杆菌的抗菌活性。结果：添加磷酸锆载银抗菌剂,醋酸洗必泰,三氯新的藻酸盐印模材料对金黄色葡萄球菌的抗菌率分别为99．85％,99．75％,99．91％;对大肠杆菌的抗菌率分别为99．83％,99．44％,99．89％。经检验,3种材料对两种菌株的抗菌率均无统计学差异（P〉0．05）。结论：以1％的比例添加3种抗菌成分的藻酸盐印模材料对金黄色葡萄球菌和大肠杆菌均具有良好的抗菌效果。采用薄膜密着法对藻酸盐印模材料进行抗菌性能的评价具有可行性。     

几种有效消毒方法对藻酸盐印模精度的影响

目的：比较几种有效的消毒方法对藻酸盐印模精度的影响，以寻求适合临床的消毒方法。方法：制作一个标准下颌牙列金属母模。采用3种有效的消毒方法（1500mg／L的NaClO消毒液浸泡消毒，1500mg／L的NaClO消毒液喷涂消毒及2％戊二醛消毒液浸泡消毒），分别按起效作用时间、起效作用时间延长10min和延长20min共分为9个实验组，每组均制备10个藻酸盐印模进行消毒处理后灌制模型，另外制取10个未消毒的藻酸盐印模作为对照组，用测量显微镜测量模型各标志点的距离，所得数据进行统计分析。结果：①1500mg／L的NaClO消毒液浸泡消毒10～30min对印模精度无明显影响。②1500mg／L的NaClO消毒液喷涂消毒藻酸盐印模45min时，出现统计意义显著的形变（P〈0．05）。③2％戊二醛消毒液浸泡处理50min、60min时，印模出现统计学意义显著的形变（P〈0．05）。结论：不影响藻酸盐印模精度的消毒方法为：1500mg／L的NaClO消毒液浸泡消毒10～30min，1500mg／L的NaClO消毒液喷涂消毒25～35min，2％戊二醛消毒液浸泡处理40min。     

胶结剂对糊剂藻酸盐印模材料凝固速度的影响

糊剂藻酸盐印模材料是目前口腔修复治疗中普遍使用的印模材料,它的胶结剂是二水石膏,即生石膏。自然界存在的生石膏常见的有二种结晶形态,一种为纤维状,一种为雪花状。本文选用湖北省应城石膏矿生产的纤维石膏和湖北省荆门石膏矿的雪花石膏作为糊剂藻酸盐印模材料的胶结剂,测量了它们与糊剂反应的凝固时间及温度对两种不同结晶形态石膏与糊剂反应速度的影响。 1 材料和方法 1.1 材料 湖北应城石膏矿生产的纤维石膏和湖北荆门石膏矿生产的雪花石膏,粉碎后用振动筛对其进行粒度分级,选用80目和120目的粉料作胶结剂。 糊剂藻酸盐印模材料:糊剂由鄂医大口腔医学院口腔药物材料厂生产,批号:980601。     

新型可注射型藻酸盐印模材料的制备与印模精度评价

目的 研制一种新型可注射型藻酸盐印模材料,评价其准确性。 方法 将一定比例的海藻酸钠、磷酸三钠、氟钛酸钾、硅藻土等成分用水溶解,行星离心搅拌机混合均匀,获得一定黏度的基质组分;将一定比例半水硫酸钙、氧化镁、甘油、聚乙二醇（PEG）400离心搅拌机混合均匀,获得同样黏度的胶结剂组分。基质组分与胶结剂组分封装在2∶1体积比的A/B胶管内。使用时用与A/B胶管匹配的注射枪和混合头加压混合。样本分为3组：以注射型藻酸盐印模材料（IA组）作为实验组,Jeltrate藻酸盐印模材料（JA组）和Silagum-putty/light加成型硅橡胶印模材料（SI组）为对照。通过扫描电子显微镜（SEM）观察注射性藻酸盐印模材料的内部形貌,数字三维测量方法评价印模材料的准确性。 结果 SEM结果显示注射型藻酸盐印模材料比Jeltrate藻酸盐印模材料结构致密均匀,气泡含量较少。IA组、JA组、SI组模型与标准模型的差异性（正确度）分别为（49.58±1.453）、（54.75±7.264）、（30.92±1.013）μm。IA组、JA组、SI组内模型之间的差异性（精密度）分别为（85.79±8.191）、（97.65±11.060）、（56.51±4.995）μm。3组印模材料在正确度和精密度上差异有统计学意义（P<0.05）。 结论 新型可注射型的藻酸盐印模材料的准确性优于传统的粉剂型藻酸盐印模材料,但差于加成型硅橡胶印模材料。新型可注射性的藻酸盐印模材料具有良好的操作性能和印模准确性,显示出良好的应用前景。     

常用消毒方法灭活藻酸盐印模表面乙肝病毒的效果

目的:观察几种常用消毒方法灭活藻酸盐印模表面乙肝病毒的效果.方法:采用ADA建议的消毒方法,对表面污染有乙肝病毒血清的藻酸盐印模进行消毒实验,采用酶联免疫分析法(Elisa)对乙肝病毒表面抗原灭活效果进行检测.结果:1500mg/L的NaClO消毒液浸泡消毒10min或喷涂消毒25min可完全灭活HBsAg;2%中性强化戊二醛消毒液浸泡消毒40min可完全灭活HBsAg;2%中性强化戊二醛消毒液喷涂消毒60min灭活HBsAg效果不可靠;臭氧消毒60min仍无效.结论:浓度为1500mg/L的NaClO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40 min三种消毒方法可灭活印模表面的乙肝病毒.     

藻酸盐印模材料致过敏性接触性口炎1例

藻酸盐类印模材料具有良好的流动性、可塑性,印模准确,尺寸稳定,价格低廉,使用方便,在临床应用广泛。笔者报道冠修复时对藻酸盐印模材料过敏反应1例,供临床同道借鉴。     

浸泡消毒对藻酸盐印模模型精度的影响

目的 了解戊二醛和二氧化氯对两种印模浸泡消毒后对模型精度的影响。方法 用标准试件制取贺利氏和红叶藻酸盐印模。每种材料取7组，1组用清水冲洗作为对照，其余各组分别用2％戊二醛和7．35mol／L（500ppm）二氧化氯浸泡10、20、30min后用超硬石膏灌模，静置24h后用电子数显游标卡尺测量模型并行统计分析。结果 两种印模在2％戊二醛中浸泡，除贺利氏浸泡10min外，其它各组较对照组均有形变（P〈0．05）；7．35mol／L二氧化氯浸泡，各组较对照组均无明显形变（P〉0．05）。结论 7．35mol／L二氧化氯对藻酸盐印模形变的影响比2％戊二醛小；用2％戊二醛和7．35mol／L二氧化氯浸泡消毒贺利氏和红叶两种藻酸盐印模，10min内不影响印模的精度。     

载银纳米TiO2抗菌剂对藻酸盐印模材料抗菌性能的影响

目的:研究载银纳米二氧化钛(Ag-TiO₂)抗菌剂对藻酸盐印模材料抗菌性能的影响,分析其最佳添加比例。方法:常温下将载银纳米TiO₂粉末按不同质量分数0~3.5%加入藻酸盐印模中,采用薄膜覆盖法检测藻酸盐印膜材料的抗菌性。结果:分析实验数据可知实验组与对照组比较差异均有统计学意义(均为P<0.05),并且随着Ag-TiO₂抗菌剂添加质量比的增高,抗菌率明显增高 ,在抗菌剂质量分数达到2.0%时,藻酸盐印膜材料抗菌率达到99%以上,2.0%为其最佳添加比例。结论:添加Ag-TiO₂抗菌剂对藻酸盐印模材料具有抗菌性,且2.0%为抗菌剂的最佳添加质量比。     

藻酸盐印模材料特性及在口腔修复临床中的应用

目的:将藻酸盐印模材料更好地应用于口腔修复临床.方法:了解和掌握藻酸盐印模材料的保存,贮藏与性能,以及它在应用于各类临床修复中的注意事项.结果:正确应用藻酸盐印模材料,可获得准确,清晰的印模,结论:藻酸盐印模材料应妥善保存和规范使用才能获取精确印模.     

洗必泰溶液调拌藻酸盐印模的模型精度研究

目的:研究0.2%洗必泰溶液调拌藻酸盐印模材料,观察其对模型精度的影响.方法:以教学用标准树脂模型为母模,采用实验法(0.2%洗必泰作调拌液)和常规法(自来水作调拌液)调拌藻酸盐粉剂,各取下颌印模10个,灌注石膏模型后用螺旋CT扫描,利用软件做三维重建处理,计算机自动测量三维图像中有关线距.用单因素方差分析和单样本t检验进行统计分析.结果:洗必泰溶液调拌组和常规调拌组印模精度无显著性差异.结论:0.2%洗必泰调拌藻酸盐印模材料不影响印模精度.     

Surface reproduction of pH-adjusted alginate impression materials

By blending with acidic Coe Alginate, pH of 9 brands of alginates, most of which were alkaline, was purposely shifted toward an optimal range for the setting of a dental stone. When the blend proportion was optimal, surface quality and reproduction of the stone casts poured against these alginates surpassed considerably those obtained with the same original brands. This result suggests that the formulation of the majority of contemporary brands of alginates is inadequate and should be revised so as to shift pH to that of dental stones to be used in combination.     

玉洁新消毒液调拌藻酸盐印模材临床效果评价

目的:应用玉洁新消毒液调和藻酸盐印模材料拓取牙颌模型后,评价印模表面细菌含量及模型尺寸精度的变化。方法:取印模前用无菌棉拭子在志愿者前牙舌侧窝采样,而后用玉洁新消毒液漱口,3min后应用玉洁新消毒液调和藻酸盐印模材料取模,于印模所对应的前牙舌侧窝处取样,4h内送检,接种于营养琼脂平皿,37℃培养48h,进行细菌定性分析。再以同一金属模型为母模,应用玉洁新消毒液调和藻酸盐印模材料制取10个印模,以超硬石膏灌模,比较石膏模型与母模之间指标线段长度差异。结果:(1)消毒前有细菌存在,消毒后印模细菌阴性培养率为100%。(2)经测量灌制的石膏模型与母模之间指标线段长度形变率为0.15%-0.18%。结论:结果显示从统计学和临床的观测,应用玉洁新消毒剂自体消毒印模所合成的石膏模型并不引起显著的尺寸改变。     

Effect of disinfecting solutions on accuracy of alginate and elastomeric impressions

Abstract— The effect of immersion in six disinfecting solutions on the accuracy of 10 impression materials was investigated. Impressions were taken of a truncated steel cone. After setting, the impressions were either stored at room temperature for 24 h, for control, or immediately immersed in a disinfecting agent for 60 min (in one case 10 iron), and after 24 h poured with gypsum. A steel ring fitting the steel cone was placed on the resulting dies, and the discrepancy between the top surface of the ring and the die was measured. From these measurements the deviation between the base diameter of the die and of the impression was calculated to express the inaccuracy. All impressions except some in Blueprint exhibited a net shrinkage, giving rise to too large die stones and incomplete seating of the steel ring. Blueprint impressions, however, occasionally swelled and resulted in too small die stones and "overseating" of the steel ring. The disinfecting solutions had no significant impact on two impression materials. For the remaining eight materials the accuracy was decreased, increased, or unaffected by the immersion. Generally, the accuracy of the alginates investigated were more affected by the disinfecting solutions than were the elastomeric impression materials. The accuracy of the three alginates was drastically impaired by immersion in 70% ethanol, whereas the remaining five disinfecting solutions had a smaller, though sometimes statistically significant, effect on the accuracy. For the elastomeric materials only a few specific combinations of impression material and disinfecting solution reduced the accuracy. Since the control values of accuracy varied, it was concluded that the choice of elastomeric impression material is more critical than the choice of disinfecting agent. As for the alginates, brand as well as type of disinfecting solution have to be considered to obtain an acceptable accuracy of disinfected alginate impressions.     

The effects of disinfectants on the dimensional stability of alginate impression materials

Glutaraldehyde and hypochlorite solutions have been shown to be effective disinfectants for use in the dental surgery. However, their use in the disinfecting of alginate hydrocolloid impression materials must be open to question since these materials are dimensionally unstable when immersed in aqueous solutions for any length of time. This project investigated the dimensional changes noted in casts poured into alginate impressions which had been stored for up to 60 minutes in either hypochlorite or glutaraldehyde solutions. All changes measured were considered to be within clinical tolerance.     

Elastic and plastic properties of elastic dental impression materials

Strain in compression, compression set, stiffness and Shore A hardness of 36 brands of elastic dental impression materials have been determined. There was no correlation between compression set and the other properties tested, while statistically highly significant correlations were found between strain in compression, stiffness and Shore A hardness. It is recommended to routinely determine Shore A hardness for a sufficiently accurate prediction of stiffness and strain in compression. The stiffness is directly proportional to the force necessary to remove an impression from undercut areas in the mouth.     

A laboratory study of dimensional changes for three elastomeric impression materials using custom and stock trays

Clinical success of fixed prosthodontic procedures is dependent in part upon the dimensional accuracy of elastomeric impression materials and impression procedures. Three elastomeric impression materials were used in custom and stock trays to determine the accuracy of impressions taken from an experimental stainless steel model representing premolar and molar bridge abutment preparations. Horizontal and vertical individual abutment and interabutment dimensions were measured on die stone replicas, and the measurements compared with those obtained from stainless steel master models. The results of this study demonstrate polysulphide is the least accurate impression material for both vertical and horizontal individual abutment dimensions. However, for interabutment horizontal dimensions, no statistical differences were noted between impression material types when using a custom tray. Stock trays produced unreliable results for all the materials tested.