Comparison between two radiological methods for assessment of tooth root resorption: an in vitro study

Purpose. This study aims to verify the validity of the radiographic image and the most effective radiological techniques for thediagnosis of root resorption to prevent, cure, and reduce it and to verify if radiological images can be helpful in medical andlegal situations. Methods. 19 dental elements without root resorption extracted from several patients were examined: endooral andpanoramic radiographs were performed, with traditional and digital methods. Then the root of each tooth was dipped into 3-4mmof 10% nitric acid for 24 hours to simulate the resorption of the root and later submitted again to radiological examinations andmeasurements using the same criteria and methods. Results. For teeth with root resorption the real measurements and the valuesobtained with endooral techniques and digital sensors are almost the same, while image values obtained by panoramic radiographsare more distorted than the real ones. Conclusions. Panoramic radiographs are not useful for the diagnosis of root resorption. Theendooral examination is, in medical and legal fields, the most valid and objective instrument to detect root resorption. Althoughthe literature suggests that CBCT is a reliable tool in detecting root resorption defects, the increased radiation dosage and expenseand the limited availability of CBCT in most clinical settings accentuate the outcome of this study.1. IntroductionHistologically root resorption is an irreversible demineralizationof the cementum (sometimes of the dentin) ofthe surface of the root of a tooth [1]. Diagnosis can bedone by anamnestic data and careful clinical observation,but only radiological examinations are determinant, oftenexclusive, and usually conclusive. Causes of root resorptioncan be general or local: endocrine pathologies, significantoral dysfunctions, osteoporosis, traumas or external causes(orthodontic treatments), expanders, intrusion movements,aggressive or inappropriate orthodontic therapy, and therapyin patients with predisposition for root resorption (traumas,osteoporosis, or hypothyroidism) [2–4].There are several theories about root resorption: Becks etal. [