Aminsobhani Mohsen, Avval Arvin Rezaei, Hamidzadeh Fatemeh
Faculty of Dentistry/Dental Research Center, AJA and Tehran University of Medical Sciences, Tehran, Iran.
Department of Endodontics, Faculty of Dentistry, Tehran University of Medical Science, Tehran, Iran.
Int J Dent. 2021 Nov 24;2021:4877619. doi: 10.1155/2021/4877619. eCollection 2021.
The ideal root canal preparation is where the original canal morphology is maintained during the biomechanical preparation. Preparation of curved canals has always been a challenge to clinicians. Better results have been suggested for a single NiTi instrument with reciprocating motion than the conventional continuous rotation method in the preparation of curved root canals. Although the Neoniti rotary system is not suggested to be used with reciprocal motion, running a pilot study, we found that it could be possible. The present study aimed to investigate if shaping curved canals using the Neoniti rotary system with reciprocal motion leads to better results in terms of root canal transportation. One hundred acrylic j-shape canal simulator endoblocks were used in this study. Five preparation sequences were applied: GPS followed by A1#20 (GPS + A1#20), GPS followed by A1#20 and then A1#25 (GPS + A1#20 + A1#25), GPS followed by A1#25 (GPS + A1#25), hand file followed by A1#20 (hand file + A1#20), and GPS followed by A1#20 (with reciprocal motion) (GPS + A1#20(reciprocal)). Pictures were taken from blocks once before and once after preparation from two dimensions. Before-and-after pictures were superimposed in Photoshop software. Measurements were performed in Digimizer. The number of autoreverses and pecking motions was recorded after reviewing the recorded videos. Data were analyzed in SPSS, version 26. A value of less than 0.05 was considered statistically significant. The group GPS + A1#20 + A1#25 had more transportation compared with the others, at apical, middle, and coronal thirds not only in the frontal view but also in the lateral view. Other groups were not significantly different. The number of peckings and autoreverses was significantly less when A1#25 was used after GPS and A1#20. When A1#20 was used with reciprocal motion, it had less peckings compared with the same file with continuous rotation, and no autoreverses were observed in that group. Using Neoniti files with reciprocal motion might result in less instrument fatigue and favorable results, with respect to canal anatomy preservation. Using A1#20 before A1#25 also will decrease the stress on the instrument during preparation. However, this may lead to significantly more canal transportation.
理想的根管预备是在生物力学预备过程中保持原始根管形态。弯曲根管的预备一直是临床医生面临的挑战。在弯曲根管预备中，有研究表明，使用具有往复运动的单一镍钛器械比传统的连续旋转方法能取得更好的效果。尽管不建议将Neoniti旋转系统用于往复运动，但通过开展一项初步研究，我们发现这是可行的。本研究旨在调查使用具有往复运动的Neoniti旋转系统对弯曲根管进行塑形，在根管偏移方面是否能取得更好的效果。本研究使用了100个丙烯酸J形根管模拟体块。应用了五种预备顺序：先用通用预备系统（GPS）再用A1#20（GPS + A1#20），先用GPS再用A1#20然后用A1#25（GPS + A1#20 + A1#25），先用GPS再用A1#25（GPS + A1#25），先用手动锉再用A1#20（手动锉 + A1#20），以及先用GPS再用A1#20（采用往复运动）（GPS + A1#20（往复））。在预备前后从两个维度对体块进行拍照。将预备前后的照片在Photoshop软件中进行叠加。在Digimizer中进行测量。在查看录制的视频后记录自动反转和啄击动作的次数。在SPSS 26版中对数据进行分析。P值小于0.05被认为具有统计学意义。GPS + A1#20 + A1#25组在根尖、中部和冠部三分之一处，不仅在正视图中而且在侧视图中，与其他组相比有更多的根管偏移。其他组之间无显著差异。当在GPS和A1#20之后使用A1#25时，啄击和自动反转的次数显著减少。当A1#20采用往复运动时，与连续旋转使用同一锉相比，其啄击次数更少，并且在该组中未观察到自动反转。采用往复运动使用Neoniti锉可能会减少器械疲劳并在保留根管解剖结构方面取得良好效果。在A1#25之前使用A1#20也会在预备过程中降低器械上的应力。然而，这可能会导致显著更多 的根管偏移。
