关键词: 根管制备, 桩核技术, 漏斗状根管, 微渗漏, 循环加载\ 透明化处理

Abstract: Abstract:Objective To compare the difference of the microleakage repaired by direct method and indirect method of the funnel shaped root canal in the anterior teeth. Methods A total of 22 middle teeth at the similar size were collected, prepared into funnel root canal after finishing the root filling. The teeth were divided into A and B groups randomly, and there were 11 test pieces in each group. The root canal was repaired by direct method in group A and indirect method in group B. After 500 thermal- cold cycling and 240 000 dynamic cyclic loading，one tooth was selected in each group randomly. The microstructure were observed by scanning electron microscope (SEM). One piece of each group was randomly selected and the image of the core and the dentin was scanned by electron microscope. The remaining 20 pieces were dyed by India ink, dealt with transparent, compared and observed under the microscope. The degree of microleakage was recorded and analyzed in two groups. Results Under electron microscope, a gap can be observed in the bonding interface of group A. The gap was significantly bigger than that of group B. The leakage was significantly serious in group A than that in group B (P <0.05). Conclusion The level of microleakage of anterior teeth with flared canals, which is restored by fiber post core with the indirect method, is significantly better than that with the direct method. The indirect method has a good edge seal action and is more suitable for clinical application.

Key words: root canal preparation, post and core technique, flared roots, microleakage, cyclic loading test, transparent processing