Comparative Analysis of Root Canal Morphology in Human Mandibular Permanent Incisors using Decalcification Technique and Periapical Radiographs: An In-vitro Study

Abstract

Introduction: Understanding the intricate root canal system of mandibular incisors is crucial for successful root canal therapy. Variations in canal anatomy pose challenges in diagnosis and treatment planning, emphasising the need for comprehensive evaluation methods. Aim: To evaluate and assess the root canal configuration of permanent mandibular incisors based on Vertucci’s classification using periapical radiographs and correlating the same with the gold standard decalcification and dye-penetration technique. Materials and Methods: The current in-vitro study was carried out from December 2018 to March 2019 in the Department of Conservative Dentistry and Endodontics, Dr. R. Ahmed Dental College and Hospital, Kolkata, West Bengal, India. It analysed the root canal morphology of mandibular central and lateral incisors using radiographic examination and decalcificationdye penetration evaluation. Data from 50 central and 50 lateral incisors (100 mandibular incisors) were procured and were assessed and subsequently analysed statistically using International Business Machines (IBM) Statistical Package for the Social Sciences (SPSS) Statistics for Windows, Version 27.0 (Armonk, NY: IBM Corp). The study outcome included assessing the various canal types and configurations, types of canals (straight/curved), and the position of the apical foramen (labial/ lingual) by both techniques. The existence of agreement was also tested using statistical analysis by the kappa (κ) coefficient between the two techniques with an alpha level of 5%. Results: The radiological findings of mandibular central incisors revealed a predominant presence of Type-I canals, constituting 66 (66%) cases, according to Vertucci’s classification. Decalcificationdye penetration evaluation of central incisors showed a similar trend, with Type-I canals exhibiting a significantly higher percentage 35 (70%) compared to other canal types (p<0.001). Lateral incisors exhibited similar trends in both radiological findings and decalcification-dye penetration. Type-I canals were significantly more prevalent 29 (58%) compared to other types (p<0.001). Evaluation with the decalcification-dye penetration technique further supported this, with Type-I canals showing a higher percentage 27 (54%) compared to other types (p<0.001). A moderate amount of agreement was detected between the two modalities concerning canal configuration (κ=0.46, p=0.049) and position of the apical foramen (κ=0.43, p<0.001), while an almost perfect agreement was present on canal curvature (κ=0.85, p<0.001). Conclusion: These results collectively suggest a similarity in the radiological characteristics and decalcification-dye penetration patterns between central and lateral incisors.