目的:比较应用椅旁CAD/CAM技术,三种不同全瓷材料制作的髓腔固位冠边缘和内部适合性的差异,以期为临床全瓷材料的选择提供参考.方法:用钴铬合金制作一个髓腔固位冠基准模型,并复制出36个超硬石膏模型,随机分为3组,采用Cerec AC扫描获取光学模型并制作修复体,粘接后,包埋、切割,利用三维测量系统测量髓腔固位冠边缘及内部粘接剂厚度并进行统计学分析.结果:三种全瓷材料边缘粘接剂厚度均小于120μm,内部的粘接剂厚度均小于200μm.在边缘、轴角和轴髓角处,Celtra(R) Duo的粘接剂厚度(84.69±8.90μm,129.89±17.86μm,166.63±21.71μm)分别小于Cerec block(107.36±8.98μm,161.13±19.35μm,198.86±11.56μm)和IPS e.max CAD(110.85±4.58μm,183.81±22.00μm,195.81±13.25μm),且差异具有统计学意义(P＜0.05);而Cerec block和IPS e.max CAD之间差异无统计学意义;在其它测量位点三种材料的粘接剂厚度两两比较差异均无统计学意义.结论:基于本研究结果,应用椅旁CAD/CAM技术制作髓腔固位冠时,三种全瓷材料的边缘和内部适合性都能达到临床要求,Celtra(R) Duo的边缘和内部适合性优于IPS e.maxCAD和Cerec block.%Objective:To compare marginal and internal adaption of prostheses manufactured from three different ceramics with a chairside CAM/CAM system and provide experimental evidence for their clinical application.Methods:A basic preparation of endocrown was made of cobalt-chromium alloy and 36 impressions were taken and poured with die-stone.36 models were randomly divided into 3 groups (n=1 2).The models were scanned and the protheses were fabricated with Cerec AC.The protheses were cemented to the models with resin cement and embedded with self-cure resin,and then cut with a cutting machine.The thickness of adhesive between prothesis and the die were measured with Smartscrope MVP 2000.Results:The thickness of adhesives at marginal sites of all three ceramics was smaller than 120μm,and that of internal measuring sites was all smaller than 200μm.At the marginal,axial-occlusal corner and axial-pulpal corner sites,the thickness of adhesive of Celtra(R) Duo (84.69± 8.90μm,129.89± 17.86μm,166.63 ± 21.71 μm) was smaller than Cerec block (107.36± 8.98μm,161.13± 19.35μm,198.86± 11.56μm) and IPS e.max CAD (110.85±4.58μm,183.81±22.00μm,195.81± 13.25μm) respectively,and there was a significant difference between them (P＜0.05),however,the difference between Cerec block and IPS e.max CAD was not significant.At all the other measuring sites,there were no statistical differences among Celtra(R) Duo,Cerec block and IPS e.max CAD.Conclusions:All these three ceramics could meet the clinical requirements.Celtra(R) Duo shows better than IPS e.max CAD and Cerec block in marginal and internal adaption of endocrowns fabricated by a chairside CAM/CAM system.
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