Sberna M T, Rizzo G, Zacchi E, Capparè P, Rubinacci A
Department of Odontoiatrics, Scientific Institute H San Faffaele, Milan, Italy.
Int Endod J. 2009 Jan;42(1):66-75. doi: 10.1111/j.1365-2591.2008.01452.x.
To evaluate the use of peripheral quantitative computed tomography (pQCT) for qualitative and quantitative analysis of root canal anatomy and for assessing the extent of canal enlargement during root canal instrumentation.
The volume variation achieved by S1 ProTaper instruments in the coronal third of the root canals was analysed using peripheral computed tomography. The tooth was scanned in the horizontal plane producing 36 consecutive cross-sectional images. All images were the result of 360 projections with a section thickness of 250 microm, a distance between slices of 0.5 mm and an in-plane pixel size of 70 x 70 microm. The evaluation was completed before and after S1 ProTaper instrumentation (with or without circumferential filing) of one root canal of a freshly extracted maxillary first premolar tooth. The acquired images were realigned geometrically and processed using a 3D visualization software. pQCT scanning allowed 3D reconstruction of the root canal anatomy and the assessment of the extent of canal enlargement during root canal instrumentation with lateral displacement of canal walls and hence volume change being greater than the coefficient of variation. The densitometry evaluation showed uniform density along the root canal wall.
评估外周定量计算机断层扫描(pQCT)在根管解剖结构定性和定量分析以及评估根管预备过程中根管扩大程度方面的应用。
使用外周计算机断层扫描分析了S1 ProTaper器械在根管冠三分之一处实现的体积变化。在水平面上扫描牙齿,生成36个连续的横截面图像。所有图像均为360次投影的结果,切片厚度为250微米,切片间距为0.5毫米,平面内像素大小为70×70微米。在对一颗新鲜拔除的上颌第一前磨牙的一个根管进行S1 ProTaper预备(有或无圆周锉削)之前和之后完成评估。采集的图像进行几何重新对齐,并使用3D可视化软件进行处理。pQCT扫描允许对根管解剖结构进行三维重建,并评估根管预备过程中根管扩大的程度,根管壁侧向移位,因此体积变化大于变异系数。密度测定评估显示根管壁密度均匀。