Saunders W P, Saunders E M, Gutmann J L, Gutmann M L
Glasgow Dental Hospital and School, Department of Adult Dental Care, UK.
Int Endod J. 1993 May;26(3):184-9.
The effect of post space preparation on the apical seal of teeth roots treated with the plastic-cored Thermafil was studied in vitro. Single rooted teeth with mature apices were prepared chemomechanically and obturated with alpha-phase gutta-percha, Thermafil, on plastic core-carriers and sealer, Sealapex. The teeth were divided randomly into four groups of 18 teeth each. In two of the groups post space was prepared by hand using a Parapost drill (diam. 1.25 mm) after gutta-percha removal with Peeso reamers in a slow-speed handpiece, one group immediately after canal obturation and the other after storage in 100% relative humidity at 37 degrees C for 1 week; 5 mm of root filling was left intact. The time taken to remove the gutta-percha was recorded. Post space was not prepared in the control groups. Apical leakage was determined using black India ink. The teeth were demineralized, rendered transparent, and linear measurement of dye penetration was recorded. Results showed that there were no significant differences in leakage between any of the groups (P > 0.05). There was no statistically significant difference in the time required to remove the gutta-percha from the root canals in both groups (P < 0.05). It is concluded that under the conditions of this study post space preparation immediately after obturation, or after a delay of 1 week, does not affect the apical seal of Thermafil with plastic core-carriers.
体外研究了桩道预备对采用塑料芯热牙胶尖充填根管的牙根根尖封闭性的影响。选取根尖发育成熟的单根牙，采用化学机械法预备根管，并用α相牙胶、塑料芯载体热牙胶尖及根管封闭剂Sealapex进行充填。将牙齿随机分为四组，每组18颗。其中两组在使用低速手机配合Peeso扩孔钻去除牙胶后，用Parapost钻（直径1.25mm）手工预备桩道，一组在根管充填后立即预备，另一组在37℃、相对湿度100%的环境中储存1周后预备；保留5mm的根管充填物。记录去除牙胶所需的时间。对照组不进行桩道预备。使用黑色印度墨水测定根尖微渗漏。将牙齿脱矿、透明化处理后，记录染料渗透的线性测量结果。结果显示，各实验组间的微渗漏无显著差异（P>0.05）。两组去除根管内牙胶所需时间无统计学差异（P<0.05）。由此得出结论，在本研究条件下，根管充填后立即或延迟1周进行桩道预备，均不影响塑料芯载体热牙胶尖的根尖封闭性。
