Suitability of different tooth replicas for endodontic training: perceptions and detection of common errors in the performance of postgraduate students.

AIM: To compare the perceptions of students when using five different tooth replicas and to detect common errors in the performance of students that might be attributed to a specific type of tooth replica. METHODOLOGY: Five groups (n = 10 each) of artificial first maxillary molars (DEPT, DRSK, Nissin, DENTALIKE and TrueTooth) were used. All 50 teeth were mounted individually in opaque containers, distributed in 10 packages containing a sample from each with an assigned random order for students to perform root canal treatments. Ten postgraduate students each performed a root canal treatment on the five replicas, in the assigned order, and completed a satisfaction questionnaire. Three trained and calibrated endodontic educators, each with more than 15 years of experience, evaluated their performance using a grading rubric and completed a questionnaire to detect common errors attributed to a specific tooth replica. Inter-rater reliability was calculated with the interclass correlation coefficient for both consistency and absolute agreement. A two-way related measures anova was used to assess the interaction amongst evaluators and tooth groups on the average scores of students. Post hoc T3 Dunnet was used to compare groups. The perceptions of students amongst groups were compared with chi-square and linear-by-linear association tests. RESULTS: Inter-rater reliability was very high for both consistency (ICCC = 0.939; 95% confidence interval (CI) 0.902-0.964) and absolute agreement (ICCA = 0.940; 95% CI 0.904-0.965). No significant differences were found amongst the ratings of evaluators; however, students performed differently when using the various tooth replicas (P < 0.05). Overall, 60% of students preferred the DRSK replica for root canal treatment training purposes, followed by DENTALIKE (30%). The least preferred was TrueTooth (70% responses) due to its complex anatomy and poor resistance to instruments and heat pluggers. Evaluators detected several common errors in specific tooth replicas and preferred tooth replicas manufactured based on microCT scans of natural teeth. CONCLUSIONS: Tooth replicas manufactured based on microCT scans of natural teeth (TrueTooth and DENTALIKE) had much better acceptance amongst evaluators, although students rated and performed less well in TrueTooth replicas due to their greater level of difficulty.

[Hysterical blindness: apropos of a case]. / Ceguera histérica: a propósito de un caso.

Conversion disorders that present "neurological" symptoms are unusual, and, among them, the occurrence of blindness is very rare nowadays. We report the case of a patient with a long history of neurological-like complaints, including an episode of sudden onset blindness that eventually led to the diagnosis of somatoform disorder.