Comparative Evaluation of Microcrack Formation in Different Kinematics Using Rotary and Reciprocating File Systems: An In Vitro Study

Abstract

Aim and objective To compare root microcrack formation after root canal preparation using ProTaper Next in rotation or forward reciprocation and Waveone gold in reverse reciprocating motion. Materials and methods Buccal roots of 60 maxillary premolars with mature apices were selected, for different instrumentation techniques and divided into three groups. Coronal access was achieved and the canals were confirmed for apical patency. The canals were then instrumented using the following instrumentation techniques: ProTaper Next in rotation or forward reciprocation or Waveone gold in reverse reciprocation. The tooth was then subjected to sectioning using a diamond saw under water cooling and then was visualized under the stereomicroscope for dentinal microcrack. Results The results showed that the maximum dentinal microcrack formed at apical 3 and 6 mm was in Waveone gold in reverse reciprocation followed by ProTaper Next in forward reciprocation and rotation. However, the p value was found to be not significant at 3 and 6 mm (p value—0.082 and 0.23). Conclusion Nickle titanium rotary instruments tend to induce varied degrees of root dentinal damage during canal instrumentation. ProTaper Next files in rotation as well as forward reciprocation presented with minimal microcrack defects when compared with Waveone gold. Clinical significance Root canal preparation, when performed by manual or engine-driven techniques, has shown to produce structural defects in the root dentin. One of the causes of failures in root canal treatment is because of fracture in the dentin that occurs due to these procedures. Though all the motion kinematics caused microcracks in this study, it was seen that rotational motion produced the least structural damage to the dentin. How to cite this article Haridas K, Hariharan M, Singh P, et al. Comparative Evaluation of Microcrack Formation in Different Kinematics Using Rotary and Reciprocating File Systems: An In Vitro Study. J Contemp Dent Pract 2020;21(12):1389–1392.

Influence of Different Glide Path Techniques on Microcrack Formation after Two Different Root Canal Preparation Treatments: Micro Computed Tomography Analysis

“…Moreover, the highest number of propagated microcracks was identified in group MWOG, especially at the coronal thirds. Haridas et al ( 23 ) explained that the parallelogram cross-section of WOG files with two alternating 85° cutting edges and an off-centred cross-section means that the file contacts the root dentinal wall with only one cutting edge, which might increase the contact of the instrument with the dentinal wall, thus promoting the formation of dentinal defects. Additionally, the SS K-file’s stiffness, combined with the file’s aggressive tip in preparing the glide path, presents a great risk of affecting the canal geometry and causing crack propagation ( 24 ).…”