Ibrahim Haytham, El-Mowafy Omar, Brown James W
Faculty of Dentistry, University of Toronto, Ontario, Canada.
Int J Prosthodont. 2006 Jan-Feb;19(1):101-2.
This study determined the radiopacity of a group of nonmetallic posts.
Four specimens were cut from 7 posts, and tooth sections were cut from extracted teeth. Radiographic images of all specimens along with an aluminum step wedge were obtained on occlusal films. Optical density readings for each specimen image were determined with a transmission densitometer. Radiopacity values were subsequently calculated as equivalents of aluminum thickness.
Analysis of variance revealed significant differences in radiopacity values among the posts (P < .001). One nonmetallic post that was made of zirconium had a radiopacity value significantly greater than that of enamel. Another, made of glass fibers, acrylic resin, and fillers, had a radiopacity that was greater than that of dentin but smaller than that of enamel. The remaining 3 nonmetallic posts had radiopacity values lower than dentin.
The 3 posts with radiopacity that was lower than dentin cannot be considered sufficiently radiopaque.
本研究测定了一组非金属桩的射线不透性。
从7根桩上切取4个样本,并从拔除的牙齿上切取牙体切片。在咬合片上获取所有样本以及铝阶梯楔形块的射线图像。用透射密度计测定每个样本图像的光学密度读数。随后将射线不透性值计算为铝厚度的等效值。
方差分析显示各桩之间的射线不透性值存在显著差异(P <.001)。一根由锆制成的非金属桩的射线不透性值显著高于牙釉质。另一根由玻璃纤维、丙烯酸树脂和填料制成的桩,其射线不透性大于牙本质但小于牙釉质。其余3根非金属桩的射线不透性值低于牙本质。
射线不透性低于牙本质的3根桩不能被认为具有足够的射线不透性。