Obtaining human teeth for dental education: A cross-sectional study to create ethical and transparent processes.

OBJECTIVES: This study explores the practices of obtaining human teeth for teaching and research in Paraguay. The goal of this research is to understand whether the data supports the need to improve ethical training within dental education, including the creation of a human tooth bank (HTB) METHODS: An observational cross-sectional study was conducted. Three semi-structured questionnaires were developed, one for each target population: dental students, dentists in practice, and the general population. The questionnaires were distributed between February and April 2021, using Google Forms RESULTS: The main places where human teeth were obtained by a student are dental clinics, followed by cemeteries. 94% of students and 91% of dentists paid for teeth on at least one occasion. There is a willingness on the part of students and dentists to donate collections of teeth, and among the general population to donate their teeth if they are extracted, for both teaching and research use. Note that, 31% of students and 6% of the population are aware of what an HTB is, at the same time only 16% of dentists know how it functions CONCLUSION: The number of respondents who obtain teeth from cemeteries and who pay for their acquisition is high. Both of these practices raise ethical concerns. The implementation of informed consent for the donation of extracted teeth is practically nil; although there is a positive attitude towards its implementation. Also, there is a lack of knowledge about the role of an HTB; although the population expressed a willingness to donate extracted teeth.

The influence of periapical lesions on the repeatability of two electronic apex locators in vivo.

OBJECTIVES: To determine the influence of periapical lesions on the repeatability of two electronic apex locators (EALs), Root ZX II, and RomiApex A-15, in maxillary anterior teeth, in vivo. MATERIALS AND METHODS: After approval by the local ethics committee, 43 maxillary anterior teeth scheduled for root canal therapy were assigned to two groups. The periapical lesion (PAL) group included 21 teeth with necrotic pulps and radiographically visible periapical lesion, and the normal periapex (NPA) group consisted of 22 teeth with vital pulps and no periapical lesion. In each canal, Root ZX II and RomiApex A-15 were used to determine working length defined as the "zero" reading on the display. Two consecutive measurements were performed with each EAL on each tooth and a second operator measured the endodontic file with a digital caliper without knowledge of the EAL being used or the tooth diagnosis. The absolute value of the difference between the first and second measurement (measurement pairs) was calculated. Repeatability was evaluated by the Bland-Altman method, and an aligned ranks transformation ANOVA was conducted to compare the EALs. RESULTS: The median absolute difference between measurement pairs was significantly lower (p < 0.001) and the limits of agreement were narrower in the NPA group. Among the EALs, median absolute differences were significantly smaller for Root ZX (p < 0.001). CONCLUSIONS: Measurements were more repeatable when no periapical lesion was present. Root ZX showed better repeatability than RomiApex. CLINICAL RELEVANCE: Periapical lesions seem to influence successive in vivo measurements with EALs.