A methodology to standardize the evaluation of root canal instrumentation using cone beam computed tomography

ABSTRACT

The evaluation of root canal instrumentation is important to observe the action of endodontic instrumentsin the root canal walls. Aim: This study introduces a method to standardize the acquisition of imagesbefore and after preparing root canals by using cone-beam computed tomography (CBCT). Methods:Sixteen mandibular molars were included in acrylic resin blocks. Samples were inserted in a stablewood box, which was filled with plaster and served as a guide to reinsert the samples. The apparatuswas used for the CBCT examination before and after cervical flaring of root canals. The softwareIcatVision® was used to equalize the images before and after instrumentation with two computersoperating at the same time. The measurements between root canal center and the furcation areawere determined. The statistical analysis was performed using the t-test for paired samples (á=0.05).Results: The values for dentin thickness in the risk zone before and after root canal flaring withGates-Gliden drills were 1.096 (± 0.27) mm and 0.742 (± 0.24) (p<0.01), respectively. Conclusions:The proposed method assures the same positioning of the samples before and after root canalpreparation. It is extremely important, as any mesiodistal or buccolingual movement can producea different topogram for comparison procedures.