Ishikawa H, Sawada N, Kobayashi C, Suda H
Pulp Biology and Endodontics, Department of Restorative Sciences, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
Int Endod J. 2003 Sep;36(9):586-90. doi: 10.1046/j.1365-2591.2003.00676.x.
To evaluate and compare the efficiency of root-end preparations using ultrasonic retrotips coated with diamond and zirconium nitride.
Eighty-five extracted single-rooted teeth were root filled, and then resected 3 mm from their apices. Root-end cavities were prepared with KiS (zirconium nitride-coated retrotip), CT-5 (stainless steel tip) or diamond-coated (DC) ultrasonic retrotips, and 10 teeth served as controls. Thirty teeth were used for evaluation of the time required to prepare the root-end cavity, the number of microcracks produced on the resected surface and the number of dentinal tubule openings on the root-canal wall using scanning electron microscope (SEM) images. A further 55 teeth were used for evaluation of dye penetration following filling of the root-end cavities with Super EBA. The degree of dye penetration in millimetres was measured under the microscope after 7 days of immersion in India ink. Statistical analyses were performed using the one-way ANOVA and Scheffe's F-test as the post hoc test.
There was no significant difference in the number of microcracks and dentinal tubule openings present in the root apices prepared by the three retrotips. The time required for root-end cavity preparation using the DC retrotip was significantly less than that using the other groups (P<0.01). Positive controls showed dye penetration throughout the length of the root-end cavity, and negative controls showed no dye penetration. There was no significant difference between the three experimental groups in dye penetration.
In this laboratory study, the time required to prepare root-end cavities using KiS retrotips was the same as that using CT-5 retrotips, and longer than that using DC retrotips. There was no significant difference in the number of microcracks or dye penetration between the three kinds of retrotips.
评估并比较使用涂有金刚石和氮化锆的超声倒充填尖进行根尖倒预备的效率。
85颗拔除的单根牙进行根管充填，然后从根尖切除3mm。使用KiS（涂有氮化锆的倒充填尖）、CT-5（不锈钢尖）或涂有金刚石的（DC）超声倒充填尖制备根尖倒凹洞形，10颗牙作为对照。30颗牙用于评估制备根尖倒凹洞形所需的时间、使用扫描电子显微镜（SEM）图像评估在切除表面产生的微裂纹数量以及根管壁上牙本质小管开口的数量。另外55颗牙用于评估使用Super EBA充填根尖倒凹洞形后的染料渗透情况。在印度墨水中浸泡7天后，在显微镜下测量染料渗透的毫米数。使用单因素方差分析和Scheffe事后检验进行统计分析。
三种倒充填尖制备的根尖中微裂纹和牙本质小管开口的数量没有显著差异。使用DC倒充填尖制备根尖倒凹洞形所需的时间明显少于其他组（P<0.01）。阳性对照显示染料渗透到根尖倒凹洞形的整个长度，阴性对照显示没有染料渗透。三个实验组在染料渗透方面没有显著差异。
在本实验室研究中，使用KiS倒充填尖制备根尖倒凹洞形所需的时间与使用CT-5倒充填尖相同，且比使用DC倒充填尖更长。三种倒充填尖在微裂纹数量或染料渗透方面没有显著差异。
