不同根管印模材料对铸造桩适合性的影响

摘要

目的:比较嵌体蜡、自凝塑料、琼脂和硅橡胶印模材料制取根管印模对铸造桩适合性的影响.方法:选择离体上颌中切牙40颗,制备根管根向聚合度6°的实验标本,然后随机分为4组,每组10颗,分别用嵌体蜡、自凝塑料、琼脂和硅橡胶印模材料制取根管印模,灌注模型,模拟临床方法制作铸造桩,用玻璃离子水门汀黏固后,选择每个标本的根颈1/3的中部、根中1/3的中部横向剖开,将横剖面置于扫描电镜下观察,每个横剖面观察4个位点,以黏固剂厚度为观察指标,测量记录,每组取其平均值,各组数据两两比较.结果:嵌体蜡组黏固剂平均厚度为(41.11±3.78)μm;自凝塑料黏固剂平均厚度为(46.01±3.66)μm;琼脂组的黏固剂平均厚度为(39.42±3.85)μm；硅橡胶组的黏固剂平均厚度为(28.03±2.73)μm;嵌体蜡组与琼脂组的适合性相近,无显著性差异(P＞0.05)；嵌体蜡与自凝塑料相比适合性有显著性差异(P＜0.05)；其他材料间适合性均有显著性差异(P＜0.01).结论:4种印模材料在黏固厚度上都在允许范围内,而硅橡胶组印模制作的铸造桩,适合性优于其他材料,值得在临床上推广应用.%Aim;To compare the effect of root-canal impression materials which was made by inlay casting wax, self-curing resin, agar, and silicone rubber on casting post cores' adaptability. Methods: Forty extracted maxillary permanent central incisors were chosen to be made as laboratory sample of root-canal which root convergence angles were at 6 degree. And they were randomly divided into four groups, with each group had ten samples. In each group, root canal impressions were made by inlay casting wax, self-curing resin, agar, and silicone rubber respectively, and were perfused for cast, in order to simulate clinical methodology to generate casting post cores. After being adhered with glass ionomer cement, eachsample was positioned at the one third of root neck and at the one third of root central, and was explored transversely. The exploration interface was placed under scanning electron microscopy for observation, and each interface was observed four positioning points, with cement thickness as observation indicator. The observation result was recorded, and each group's average was adopted for group vs group comparison.Results:The average cement thickness of inlay casting was (4. 11 ±3.78)μm, (46.01 ±3.66) μm, ( 39. 42 ±3. 85 ) μn, ( 28. 03 ± 2. 73 ) μm respectively, the adaptability for inlay casting wax group and agar group were similar ( P > 0. 05 ) , the adaptability for inlay casting wax group and self-curing resin group with significant difference with ( P < 0. 05 ). The remaining groups were different adaptability ( P < 0. 01). Conclusion: All these four impression materials' cement thickness was within permit range, while the casting post core made by silicone impression was better than that made by other impression materials in terms of adaptability, it should be widely adopted for clinical application.