Evaluation of a digital learning object (DLO) to support the learning process in radiographic dental diagnosis.

AIMS: Studies have shown that inappropriate therapeutic strategies may be adopted if crown and root changes are misdiagnosed, potentially leading to undesirable consequences. Therefore, the aim of this study was to evaluate a digital learning object, developed to improve skills in diagnosing radiographic dental changes. MATERIALS AND METHODS: The object was developed using the Visual Basic Application (VBA) software and evaluated by 62 undergraduate students (male: 24 and female: 38) taking an imaging diagnosis course. Participants were divided in two groups: test group, which used the object and control group, which attended conventional classes. After 3 weeks, students answered a 10-question test and took a practice test to diagnose 20 changes in periapical radiographs. RESULTS: The results show that test group performed better that control group in both tests, with statistically significant difference (P = 0.004 and 0.003, respectively). In overall, female students were better than male students. Specific aspects of object usability were assessed using a structured questionnaire based on the System Usability Scale (SUS), with a score of 90.5 and 81.6 by male and female students, respectively. CONCLUSIONS: The results obtained in this study suggest that students who used the DLO performed better than those who used conventional methods. This suggests that the DLO may be a useful teaching tool for dentistry undergraduates, on distance learning courses and as a complementary tool in face-to-face teaching.

CBCT for the assessment of second mesiobuccal (MB2) canals in maxillary molar teeth: effect of voxel size and presence of root filling.

AIM: To compare detection of the second mesiobuccal (MB2) canal in maxillary molar teeth using cone-beam computed tomography (CBCT) with different voxel sizes against conventional radiographic examination when the MB1 was unprepared, prepared and filled. METHODOLOGY: Radiographic examination and 0.2-, 0.25- and 0.3-mm CBCT (n = 89) were performed in 3 stages: S1, no first mesiobuccal (MB1) canal preparation or filling; S2, after MB1 preparation and filling; and S3, after MB1 root canal filling removal and canal repreparation. Images were analysed using the i-Cat software. After RE and CBCT acquisition in S3, all the samples were clarified to directly visualize the presence of the MB2 canal. All images were analysed by a blinded, previously calibrated examiner. Accuracy, specificity and sensitivity were compared using analysis of variance (P < 0.05 level of significance). RESULTS: MB2 root canals were detected in 67% of the samples. Overall, radiographic examination was associated with lower mean accuracy values for detecting MB2 than CBCT regardless of the MB1 condition. The MB1 root canal condition did not influence MB2 detection in 0.2-mm voxel images. The presence of root fillings in the MB1 canals reduced the detection of MB2 canals, especially in the 0.3- and 0.25-mm voxel-size images (P < 0.05). CONCLUSION: CBCT was associated with higher mean values of specificity and sensibility than radiographic examination for the detection of MB2 canals. When endodontic retreatment is necessary removal of the root filling prior to the CBCT examination eliminates artefacts, thereby permitting the use of the 0.3-mm voxel protocol that has good diagnostic performance and lower radiation dose.

Comparative study between conventional and cone beam CT-synthesized half and total skull cephalograms.

OBJECTIVES: The aim of this study was to compare cephalometric measurements obtained from conventional cephalograms with total and half-skull synthesized cone beam CT (CBCT) cephalograms. METHODS: Cephalometric analyses of 30 clinically symmetric patients were conducted by a calibrated examiner on conventional and CBCT-synthesized cephalograms (total, right and left). Reproducibility was investigated using the intraclass correlation coefficient (ICC). The Bland-Altman analysis was used to assess the agreement of the measurements from each factor obtained by conventional, total, right and left CBCT-synthesized cephalograms. RESULTS: The ICC was above 0.9 for most of the 40 cephalometric factors analysed, revealing similar levels of reproducibility. When the measurements obtained from conventional and CBCT-synthesized cephalograms were compared, the Bland-Altman analysis showed a strong agreement between them. CONCLUSIONS: Half-skull CBCT-synthesized cephalograms offer the same diagnostic performance and equivalent reproducibility in terms of cephalometric analysis as observed in conventional and total CBCT-synthesized cephalograms.

Influence of a programme of professional calibration in the variability of landmark identification using cone beam computed tomography-synthesized and conventional radiographic cephalograms.

OBJECTIVES: The validity of any measurement obtained through a cephalogram largely depends on the reproducibility of the cephalometric landmarks. The purpose of this study is to evaluate the influence of a programme of professional calibration (PPC) on the variability of landmark identification comparing conventional radiographs and cone beam CT (CBCT)-synthesized cephalograms. METHODS: 5 graduate students in oral radiology identified 20 cephalometric landmarks from cephalograms generated from conventional radiographs (RADs), Ray-Sum CBCT-synthesized cephalograms (CBTs) and half-skull CBT (HSTs) from 10 patients. After a period of reinforcement on instruction and calibration with inter- and intraexaminer assessment of reproducibility (intraclass coefficient correlation scores > 0.75) for RADs, CBTs and HSTs obtained from 5 different patients, observers were asked to repeat the analysis of the first 10 patients under the same circumstances. Values in millimetres represented each landmark in a table of Cartesian co-ordinates (x- and y-axes). RESULTS: ANOVA showed significant reduction in variability levels after the PPC, and there were no differences among the methods of image acquisition. Repeated measures ANOVA indicated that the PPC accounted for reduction in variability levels in 14 of 20 landmarks. CONCLUSIONS: The results suggest that a PPC has more influence than the type of image acquisition on variability of landmark identification based on two-dimensional cephalometric analysis. Cephalograms obtained from RAD or CBCT can be considered equivalent for clinical and experimental applications.

Diagnostic ability of computed tomography to evaluate external root resorption in vitro.

OBJECTIVES: The aim of this study was to evaluate the diagnostic ability of CT to detect simulated external root resorption defects. METHODS: External root resorption defects of different sizes and in different locations were simulated in 59 human mandibular incisors. Cavities simulating root resorption defects of 0.6 mm, 1.2 mm, or 1.8 mm in diameter and 0.3 mm, 0.6 mm, or 0.9 mm in depth (small, medium and large defects) were drilled in the cervical, middle and apical thirds of buccal surfaces. Axial CT was used to obtain cross-sectional images of the teeth, and 177 root thirds were assessed by a blinded observer. RESULTS: Of the 131 cavities, 117 were detected (89%). 32 of the 44 (72.72%) cavities located in the apical third were identified. A statistically significant difference (P<0.01) was found between the sizes of defects examined in the apical third. CONCLUSIONS: The evaluation of CT diagnostic ability revealed high sensitivity and excellent specificity. However, small cavities located in the apical third were more difficult to detect than all other cavities.