目的

研究快速成型制造（RPM）技术制作个体化桩核的适合性，探讨RPM 技术的制作精度，以指导临床实践。

方法

（1）用数控车床精密加工残冠和（或）残根基牙代型，以螺旋CT 扫描数据建立代型数字模型；（2）分别用常规失蜡精密铸造法和RPM 技术制作桩核；（3）采用扫描电镜观测并拍片计数的方法，测量RPM 技术制作个体化桩核、常规铸造桩核的边缘适合性和内部适合性，采用组间比较t 检验进行统计学分析。

结果

制作的所有桩核均可精密就位，效果满意。 常规制作桩核和RPM 制作桩核边缘浮出量分别为（47.99±9.26）μm和（45.95±8.09）μm，差异无统计学意义（P=0.647 ＞0.05）。 常规制作桩核和RPM 制作桩核组织面与代型之间间隙，在根管口处分别为（104.31±14.14）μm 和（79.33±9.69）μm，差异有统计学意义（P=0.001 ＜0.01）；在根管中部分别为（83.91±12.86）μm 和（80.68±10.74）μm，差异无统计学意义（P=0.593 ＞0.05）；在根管底部分别为（108.51±13.61）μm 和（82.05±11.46）μm，差异有统计学意义（P=0.001 ＜0.01）。

结论

RPM 技术制作个体化桩核具有良好的适合性，优于临床常规失蜡精密铸造桩核。

Objective

To study the fitness of the post and core fabricated by the method of rapid prototyping and manufacturing （RPM） technique and to evaluate the precision of RPM.

Methods

Dies of residual root and crown fabricated by the computer numerically controlled lathe were scanned by spiral CT and a digital model was obtained.The post and core were manufactured by RPM technique and the routine casting method respectively.The fitness was measured with a scanning electronic microscope and analyzed statistically.

Results

All the posts and cores could be put in place precisely.The marginal fitness of the post and core formed by regular method and by RPM method was （47.99±9.26）μm and （45.95±8.09）μm， respectively.There was no significant difference in marginal fitness between the two methods （P ＞0.05）.The internal fitness of the post and core made by RPM method was better than that by casting method.The gap between the post and the die was （104.31±14.14）μm by RPM method and （79.33±9.69）μm by casting method respectively at the root canal orifice （P ＜0.01）， （83.91± 12.86）μm and （80.68 ± 10.74）μm respectively at the middle area of root canal （P ＞0.05）， and （108.51±13.61）μm and （82.05±11.46）μm respectively at the bottom area （P ＜0.01）.

Conclusion

The post and core formed by RPM technique had excellent precision and satisfied fitness.