Evaluation of biomechanical preparation, root canal obturation, retrofilling cavity, post space preparation, and quality of apical trabecular bone of teeth subjected to different treatment protocols, by means of micro-computed tomography

Abstract

A better understanding of the anatomical features of the teeth and the root canal system acquired from three-dimensional image platforms is essential in Endodontic research. In this way, the micro-computed tomography has emerged as an additional tool for the development of a new technological knowledge for both researchers and clinical professionals. The aim of this research project is the acquisition of three-dimensional images from a high-resolution micro-computed tomograph (SkyScan 1174), by using the MeVisLab image processing and visualization platform, for the development of seven subprojects that aiming to evaluate: (i) root canal preparation by using different instruments and techniques; (ii) the accuracy for imaging of filled root canals; (iii) the remaining filling volume of different filling materials from root-filled extracted teeth by using different removal techniques; (iv) the surface area between dentin and root-end filling materials in apicoectomized teeth; (v) a simulation of virtual post space preparations; (vi) the influence of shaft design on the shaping ability of different nickel-titanium rotary systems; (vii) the influence of different biomechanical preparation on the apical trabecular bone of teeth with periapical lesion in an in vivo model using dogs. One hundred and twenty teeth will be scanned before and after the proposed research protocols by using micro-computed tomography. The results will be obtained through analysis of images by using the MeVisLab image processing and visualization platform for three-dimensional reconstruction and assessment of tooth and root canal morphology. Concerning in vivo protocol, after periapical lesion induction, eighty-two root canals of 5 dogs will be submitted to different treatment protocols: groups I and II (manual instrumentation); groups III and IV (rotary instrumentation). After biomechanical preparation, the root canals of groups I and III will be obturated whilst groups II and IV will be filled with a calcium hydroxide dressing 15 days before obturation. The animals will be euthanasiated after 30, 75, and 120 days. In each group, half of the sample will be submitted to a conventional histological evaluation and the other half to the microtomograph. Scores will be given and data will be statistically analyzed. (AU)