Prevalence of major apical foramen mismatching the root apex in root canals of human permanent teeth

Abstract

The periapical radiograph is used to determine the working length in endodontic treatment. However, this radiograph does not define the position of the major apical foramen. Objective: This ex vivo laboratorial study aims to determine the prevalence of the major apical foramen mismatching the root apex in human permanent teeth, because when present, this mismatch makes the radiographic method inaccurate for determining the working length. Material and methods: This study used 400 human permanent teeth: 100 incisors, 100 canines, 100 premolars, and 100 molars, totalizing 634 canals (Ethics Committee, Federal University of Ceará #263/10). The access and negotiation of the root canals were performed with K-type files #10 and #15 until the tip of the instrument were visible at the root foramen through 5-fold magnifying glass. Periapical radiographs were performed on bucco-lingual incidence for single-rooted teeth; the incidence angle was changed for multi-rooted teeth. The films were processed and then analyzed by three calibrated examiners (Kappa 80%). Descriptive statistics and chi-square test were used for analyzing of the results. Results: The prevalence of major apical foramens mismatching the root apex was 19.72% of the canals studied. The incisors showed the lowest prevalence (9%, p<0.05) while the highest prevalence was seen in canine teeth (28%). Conclusion: According to the methodology applied, the prevalence of major apical foramens mismatching the root apex foramens make necessary an adjunct method for determining the working length, because it alone was not capable of determining the foramen position.