Abedi H R, Van Mierlo B L, Wilder-Smith P, Torabinejad M
Department of Endodontics, Loma Linda University School of Dentistry, Calif., USA.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1995 Aug;80(2):207-13. doi: 10.1016/s1079-2104(05)80204-5.
This study determined the effect of bur and ultrasonic preparation on the root apex. After cleaning, shaping, and obturation of root canals of 47 single-rooted teeth and resection of their apexes were done, 24 root-end cavities were prepared with a bur, and the rest were prepared with ultrasonic tips attached to two different ultrasonic units. After photographs of the prepared root ends were taken, their resin replicas were prepared and examined with a scanning electron microscope. Photographs and scanning electron microscope photomicrographs were examined for the presence or absence of cracks. The results showed a significantly higher incidence of crack formation in the walls of root-end cavities prepared by ultrasonic tips compared with those made by the bur.
本研究确定了球钻和超声预备对根尖的影响。在对47颗单根牙进行根管清理、成形和充填并切除根尖后，用球钻制备24个根尖倒充填窝洞，其余用连接于两种不同超声设备的超声头进行制备。在拍摄所制备根尖的照片后，制作其树脂复制品并用扫描电子显微镜检查。检查照片和扫描电子显微镜显微照片中是否存在裂纹。结果显示，与球钻制备的根尖倒充填窝洞壁相比，超声头制备的根尖倒充填窝洞壁出现裂纹的发生率显著更高。
