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