咬印模法模型精确性及其在后牙冠修复的临床效果

A Research on the Precision of Occlusal Impression Method and Its Clinical Effect in Posterior Teeth Crown Prosthesis

目的探讨后牙咬印模法模型精确性及其在后牙冠修复的临床效果。方法采用硅橡胶后牙咬法及常规硅橡胶一次印模法对已预备牙体的标准模型进行复制,测量牙体肩台与各轴面交角形成的周长以及在预备牙体前后邻牙颊面设定的2点间距离,分析后牙咬法的模型精准性;在临床研究中,分别按照两组方法制取患者模型各75例,记录修复体试戴过程中邻接面接触情况、肩台边缘密合度情况、以及是否需要咬调整,比较2种方法的临床效果。结果两种印模方式复制标准模型后测量数据分别与标准模型均大于0.05,无显著性差异;在临床试戴效果资料显示邻接面和边缘密合度P>0.05,无显著性差异,但咬调整P<0.01,具有显著性差异。结论后牙咬法与一次印模法同样可获取精确的模型,但是后牙咬法在确定后牙咬关系及稳定性优于一次印模法。

Objective To explore the precision of occlusal impression method and its clinical effect in posterior teeth crown prosthesis. Methods The standard model with prepared teeth was respectively replicated with occlusal method and impression method in one time using silicone rubber. The perimeter defined by the angles between the shoulder and various axial planes as well as the distance between two points set by the front and back adjacent buccal surfaces were measured. The precision of occlusal method and impression method were analyzed by T test using SPSS18. 0 statistical software. In clinical study,75 patient models were made with each method. During the process of trying on the definitive restoration,contact between proximal surfaces,marginal fitness of shoulder and need for occlusal adjustment were recorded. The clinical results of the two methods were compared by chi- square test using SPSS18. 0 statistical software. Results After the replicating the standard model with the two impression methods,one- sample T tests（ two- sided） was conducted to compared the measured data of the two methods and the data of the standard model,and there were no significant differences（ P 〉0. 05）; comparison between the measured data of the two methods was done with independent sample T- test（ two- sided）,showing no statistically significance（ P 〉0. 05）. The recorded information about try- in suggested that there were no statistically significant differences in both proximal surface and marginal fitness between the two methods（ P 〉0. 05）,while the two methods showed a significant difference in occlusal adjustment（ P 〈0. 01）. Conclusion Both posterior occlusal method and impression method in one time perform well in making precise model,but the former plays a better role than the latter in determining posterior occlusal relationship and maintaining stability.