Synchronous vs. asynchronous education: Questionnaire-based survey in dental medicine during the COVID-19 pandemic**

Introduction: The rapid establishment of digital teaching in the dental curriculum, which was necessary in the progress of the COVID-19 pandemic, now poses new challenges for both students and teachers. The aim of this study was to assess the impact of the sudden introduction of synchronous and asynchronous online teaching on dental students. Methods: The evaluation of digital teaching was conducted via online survey using the survey program SoSciSurvey. Dental students at the MHH in the 2nd, 4th, 6th, 8th and 10th semesters were questioned (n = 204, mean age: 23.6 ± 3.7 years, male/female ratio: 28 %/72 %). By means of a sum value calculation over 21 Likert-type items, as well as the evaluation of core aspects (content, technical quality, interaction potential with the lecturer, clarification possibilities of questions, general orientation on the digital platform) according to school grades, the satisfaction of the students was recorded. The statistical evaluation was carried out with the software RStudio. Results: The evaluation of the sum scores showed a mean of 66.9 points (median 68.5) for preclinical students (2nd, 4th semester, asynchronous teaching concept) and 79.4 points (median 81) for clinical students (6th, 8th, 10th semester, synchronous teaching concept). The difference of 12.5 points (median 12.5) between both teaching concepts is statistically significant (p 0.001). The grading of the core aspects also showed statistically significant differences with regard to content and orientation on the digital platform. Conclusion: The questionnaire-based survey of dental students at the MHH revealed that students were more satisfied with synchronous online teaching than with asynchronous teaching. However, whether there is a fundamental superiority of the synchronous teaching format over the asynchronous approach cannot be answered by the data collected. Palabras clave: covid-19 pandemic, dentistry, digital teaching, questionnaire-based survey, synchronous and asynchronous learning