{'fraction_non_alphanumeric': 0.03476371537208039, 'fraction_numerical': 0.011406844106463879, 'mean_word_length': 5.3517241379310345, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Dental undergraduate students' ability in the diagnosis of root fractures: Comparative analysis of different imaging methods.

OBJECTIVE
The aim of this study was to evaluate the diagnostic ability of dental undergraduate students to detect horizontal and oblique root fractures (ORFs) using different imaging techniques.


MATERIALS AND METHODS
Nine teeth were selected and randomly divided in three groups in order to create a fracture line without fragments separation: control (without fracture), horizontal root fracture (HRF), and ORF. The root fracture was created using perpendicular force and was confirmed by transillumination. A model with two adjacent teeth was created, and different imaging techniques were performed: conventional periapical radiograph; mesially and distally shifted periapical radiographs; cone-beam computer tomography (CBCT). Twenty students that had participation on dental trauma clinic at the year of 2019 were invited to identify root fractures by a five-point scale: (i) fracture definitely not present, (ii) fracture probably not present, (iii) uncertain whether fracture is present or not, (iv) fracture probably present, and (v) fracture definitely present. Data were analyzed by Kappa test for agreement evaluation.


RESULTS
Comparing each student to the gold standard, there was a variation in reproducibility and performance from poor to substantial (0.042-0.667). Reproducibility values ranged from poor to good for all periapical radiographs both in the diagnosis of ORF (-0.33-0.667) and in HRF (0-1).


CONCLUSIONS
In CBCT images, the students' ability was lower in HRF detection in comparison with the oblique ones. The students showed limited capacity to diagnose root fractures; however when CBCT was used, the performance was more satisfactory than when periapical radiographs were used.