Fracture Prediction of the Self Adjusting File Using Force and Vibration Signature Analysis

Abstract

The self-adjusting file (SAF) is the most popular endodontic file of the latest generation. Unique properties of the SAF like adjustable, adaptable, thin-walled, hollow pointed cylindrical lattice-like structure and shaping ability, makes it different from other endodontic files. Endodontist can easily shape oval or flat root canals using the SAF. The SAF has abrasive particles on the lattice structure. It performs transline motion in the root canal at 83.33 Hz. In the transline motion of the SAF, abrasive particles dislodge material from the inner wall of the root canal. During root canal shaping, the endodontic instruments may get fractured which is one of the iatrogenic error involved with root canal instrumentation. Continuous monitoring of the endodontic file may help to avoid such fracture of the SAF. In this work, force and vibration signatures of the SAF were analyzed to predict the fracture of the SAF. For force and vibration analysis simulated root canals (Endo Training Bloc-J) were held in a vice which was connected with the accelerometer and dynamometer to acquire force and vibration signature of root canal shaping. The features from force and vibration signatures were calculated. On the analysis of these features, the failure of the SAF was predicted. It was concluded that the vibration signature of the simulated root canal can be used to predict the fracture of the SAF to prevent the treatment from iatrogenic errors related to instrument failure.