Lussi A, Imwinkelried S, Stich H
Department of Operative, Preventive and Paediatric Dentistry, University of Bern, School of Dental Medicine, Switzerland.
Int Endod J. 1999 Jan;32(1):17-23. doi: 10.1046/j.1365-2591.1999.00178.x.
To evaluate and compare the sealing quality of hand- or vacuum-obturated root canals after hand preparation or hydrodynamic cleansing of root canals, respectively.
After assessing root curvature, 96 single-rooted deep-frozen teeth were divided into eight comparable groups. The root canals of four groups were instrumented with the balanced force technique. The remaining uninstrumented teeth were connected to a reduced-pressure device (NIT) and the root-canal system perfused with 2.5% NaOCl under alternating pressure fields. This dissolved the pulpal tissues and removed debris from the root-canal system. The canals of the hand-instrumented groups were obturated using the cold lateral condensation method with guttapercha and one of four different sealers (AH26, AH Plus, Apexit and Pulp Canal Sealer EWT). The teeth treated with the alternating pressure device (NIT) were obturated by a vacuum obturation method (NIT) with the same four sealers. The quality of the coronal seal was assessed using a dye penetration method. In order to minimize errors the roots were perfused with water before exposure to the dye, under vacuum. The teeth were then rendered transparent and the depth of penetration of the dye between the wall of the canal and the obturating material was measured with a stereomicroscope.
The canals cleaned and filled by NIT showed statistically significantly less dye penetration than those obturated by lateral condensation (P < 0.05). Within the NIT group, Pulp Canal Sealer EWT exhibited significantly more dye penetration than Apexit. Amongst the control lateral condensation groups no significant differences were found between the various sealers.
The present investigation demonstrated the validity of the NIT obturation method in combination with commonly used root-canal sealers.
分别评估和比较在根管手工预备或流体动力冲洗后，手工充填或真空充填根管的封闭质量。
在评估牙根弯曲度后，将96颗单根深冻牙分为8个可比组。4组根管采用平衡力技术进行预备。其余未预备的牙齿连接到减压装置（NIT），并在交变压力场下用2.5%的次氯酸钠灌注根管系统。这溶解了牙髓组织并清除了根管系统中的碎屑。手工预备组的根管采用冷侧方加压法用牙胶和四种不同的封闭剂（AH26、AH Plus、Apexit和牙髓根管封闭剂EWT）之一进行充填。用交变压力装置（NIT）处理的牙齿采用真空充填法（NIT）用相同的四种封闭剂进行充填。采用染料渗透法评估冠部封闭的质量。为了尽量减少误差，在真空下将牙根暴露于染料之前先用清水灌注。然后使牙齿透明，并用体视显微镜测量染料在根管壁与充填材料之间的渗透深度。
NIT清洗并充填的根管染料渗透在统计学上显著少于侧方加压充填的根管（P<0.05）。在NIT组中，牙髓根管封闭剂EWT的染料渗透明显多于Apexit。在对照侧方加压组中，各种封闭剂之间未发现显著差异。
本研究证明了NIT充填法与常用根管封闭剂联合使用的有效性。
