[Classification of the level and degree of calcification of root canals by cone-beam computed tomography]

To evaluate the frequency of root canal calcification (RCC) and to propose a classification of the level and degree of RCC calcification by cone beam computed tomography (CBCT).

The sample consisted of tomographic volumes of 82 patients of both sexes (female n=61, 74.4%; male n=21, 25.4%), aged 41-71 years, of which 109 RCC were analyzed. The location of the tooth in the maxilla, type of tooth affected, type of calcified canal, level and degree of calcification were recorded; a classification was designed for the latter. Thirty percent of the sample was reevaluated by three independent observers to validate the proposed classifications, obtaining a ROC curve.

The highest frequency of ROC was found in the 40-49 years age group (23.85%), in the maxilla (n= 77, 70.64%) and second quadrant (44/109-40.4%). Monoradicular (43/109-39.0%) and single canal (51/109-46%) teeth were the most affected. Cervical-mid-apical calcification (31/109-28.4%) and calcification grade 3 (closed) (73/109-67%) had the highest frequencies. These results showed a significance level of p<0.05. The correlation for the evaluators in the ROC curve was on average 0.89, demonstrating dominance in the observation of the variables.

RCC was found more frequently in monoradicular and single root canal upper teeth, in individuals between 40 and 49 years of age. The proposed classification can be used as a visual guide to determine the level and degree of RCC through CBCT.