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Introduction: in December 2019, a case of pneumonia caused by coronavirus 2 (SARS-CoV-2) was reported in the world. Currently, Paraguay has registered more than 428,000 confirmed cases and more than 13,500 deaths. In this context, teaching has had to be transferred to the virtual environment, generating reactive behavioral modifications at all levels arising from various causes: difficulty in accessing computer elements, the need in varying degrees of relearning in an unusual environment and, above all, uncertainty. The aim of this study was to determine the levels of depression, anxiety and stress during the covid-19 pandemic in dental students. Methods: for this cross-sectional descriptive observational study, undergraduate students from the School of Dentistry of the National University of Asunción, enrolled in the academic period 2021, were included. The Depression, Anxiety and Stress (DASS-21) short form scale was used. Each of the three axes (depression, anxiety, and stress) contains 7 items, divided into subscales of similar content. The scores were categorized into five ordered groups (normal, mild, moderate, severe, and very severe). Results: dentistry students presented symptoms of depression and anxiety with symptoms of moderate anxiety in 42.58%; 1.29% presented severe depression. Conclusion: most of the dental students presented depression and anxiety with very common symptoms such as the inability to relax, lack of initiative, irritability and nervousness.

Aim: To determine the frequency of signs and/or symptoms compatible with COVID-19 in Paraguayan dentists, as well as the possible source of contagion. Material and Methods: Online survey consisting of 13 questions, applied to all dentists in Paraguay from January 20 to February 15, 2021. Results: A total of 433 dentists participated in the survey; 47.5% displayed symptoms compatible with COVID-19 and 13.39% indicated that they had contracted the disease, providing confirmation via a positive test result. Headache, loss of smell, loss of taste, cough, and fatigue were the most prevalent symptoms among COVID-19 positive cases. The main source of contagion was the family nucleus. Only one participant reported having contracted the disease while providing dental care. Conclusion: Almost half of the dentists displayed symptoms compatible with COVID-19. Only 13.39% tested positive for COVID-19. Only one case of contagion was reported to have happened during the provision of dental care.

Panoramic dental radiography is one of the most used images of the different dental specialties. This radiography provides information about the anatomical structures of the teeth. The correct evaluation of these radiographs is associated with a good quality of the image obtained. In this study, 598 patients were consecutively selected to undergo dental panoramic radiography at the Department of Radiology of the Faculty of Dentistry, Universidad Nacional de Asunción. Contrast enhancement techniques are used to enhance the visual quality of panoramic dental radiographs. Specifically, this article presents a new algorithm for contrast, detail and edge enhancement of panoramic dental radiographs. The proposed algorithm is called Multi-Scale Top-Hat transform powered by Geodesic Reconstruction for panoramic dental radiography enhancement (MSTHGR). This algorithm is based on multi-scale mathematical morphology techniques. The proposal extracts multiple features of brightness and darkness, through the reconstruction of the marker (obtained by the Top-Hat transformation by reconstruction) starting from the mask (obtained by the classic Top-Hat transformation). The maximum characteristics of brightness and darkness are added to the dental panoramic radiography. In this way, the contrast, details and edges of the panoramic radiographs of teeth are improved. For the tests, MSTHGR was compared with the following algorithms: Geodesic Reconstruction Multiscale Morphology Contrast Enhancement (GRMMCE), Histogram Equalization (HE), Brightness Preserving Bi-Histogram Equalization (BBHE), Dual Sub-Image Histogram Equalization (DSIHE), Minimum Mean Brightness Error Bi-Histogram Equalization (MMBEBHE), Quadri-Histogram Equalization with Limited Contrast (QHELC), Contrast-Limited Adaptive Histogram Equalization (CLAHE) and Gamma Correction (GC). Experimentally, the numerical results show that the MSTHGR obtained the best results with respect to the Contrast Improvement Ratio (CIR), Entropy (E) and Spatial Frequency (SF) metrics. This indicates that the algorithm performs better local enhancements on panoramic radiographs, improving their details and edges.