Accuracy of photogrammetric technologies for the scanning of dental models: A systematic review / Precisión de las tecnologías fotogramétricas para el escaneo de modelos dentales: Una revisión sistemática

Background:Traditional dental scanners require a heavy investment, representing a high barrier of entry into digital dentistry. Photogrammetric-based scanners may represent an affordable cost-effective alternative to traditional dental scanners used for the digitalization of plaster models. Photogrammetry is the science of extracting 3D information from photographs. The process involves taking overlapping photographs of an object or space and converting them into 2D or 3D digital models. Objective:This review aimedto identify and appraise the reported accuracy of photogrammetric-generated digital dental models.Materials and methods:A search strategy was applied in 3 databases (Medline, Web of Science and Scopus), from Feb 1 2021 to Dec 1 2021, the search was limited to articles in English published in the last 5 years about studies evaluating the dimensional accuracy of 3-dimensional digital models acquired by the scanning of plaster models with photogrammetric technologies.Results:Two independent reviewers screened 75 records on basis of titles and abstracts for assessment against the inclusion criteria for the review, 4 articles were deemed eligible, the risk of bias for the selected articles was measured, data extraction was performed by only one author.Conclusion:With today's technology, based on the four studies evaluated, we conclude that photogrammetric-generated digital models while lacking accuracy for incorporation into the treatment flow, in the future it could be used for diagnostic, planning, and achieving.

Antecedentes:Los escáneres dentales tradicionales requieren una gran inversión, lo que representa una gran barrera de entrada a la odontología digital. Los escáneres basados en fotogrametría pueden representar una alternativa asequible y rentable a los escáneres dentales tradicionales utilizados para la digitalización de modelos de yeso. La fotogrametría es la ciencia de extraer información 3D de fotografías. El proceso implica tomar fotografías superpuestas de un objeto o espacio y convertirlas en modelos digitales 2D o 3D.Objetivo:esta revisión tuvo como objetivo identificar y evaluar la precisión informada de los modelos dentales digitales generados fotogramétricamente.Materiales y métodos:Se aplicó una estrategia de búsqueda en 3 bases de datos (Medline, Web of Science y Scopus), del 1 de febrero de 2021 al 1 de diciembre de 2021, la búsqueda se limitó a artículos en inglés publicados en los últimos 5 años sobre estudios que evalúan la dimensión precisión de modelos digitales tridimensionales adquirida por el escaneo de modelos de yeso con tecnologías fotogramétricas.Resultados:dos revisores independientes examinaron 75 registros sobre la base de títulos y resúmenes para evaluarlos según los criterios de inclusión para la revisión, 4 artículos se consideraron elegibles, se midió el riesgo de sesgo de los artículos seleccionados, la extracción de datos fue realizada por un solo autor.Conclusión:con la tecnología actual, con base en los cuatro estudios evaluados, concluimos que los modelos digitales generados por fotogrametría si bien carecen de precisión para incorporarlos al flujo de tratamiento, en el futuro podrían usarse para el diagnóstico, la planificación y el logro.

Should We Be Concerned about the Association of Diabetes Mellitus and Periodontal Disease in the Risk of Infection by SARS-CoV-2? A Systematic Review and Hypothesis.

The objective of this article was to conduct a systematic review of the literature to contrast the existing evidence regarding the relationship between periodontal disease (PD) and diabetes mellitus (DM) with the possibly increased risk of SARS-CoV-2 infection, as well as to establish a hypothesis that explains the ways in which this interaction could take place. A literature search up from 1 January 2020 to 21 March 2021 was conducted in three electronic databases, namely, PubMed, Web of Science, and Scopus, in order to identify studies on periodontal disease alone or in conjunction with diabetes mellitus, reporting any relation with SARS-CoV-2 infection as a primary outcome. Only articles published in the English language were included. Due to the lack of studies, we decided to collect all the theoretical and clinical evidence suggesting a possible biological pathway evidencing the relationship among PD, DM, and SARS-CoV-2 infection. From a total of 29 articles, 12 were included for final review studies (five reviews, two hypotheses, one Special Issue, one perspective, one commentary, one case-control study, and one case report). In addition, this systematic review article hypothesizes the correlation between PD and type 2 diabetes mellitus (T2DM) by expression of angiotensin-converting enzyme 2 (ACE2) in periodontal tissue and the risk of SARS-CoV-2 infection. T2DM is a metabolic disorder characterized by high blood glucose levels resulting from altered insulin secretion or action. Likewise, periodontitis and T2DM are inflammatory disorders with a bidirectional association, and both diseases have a similar immunomodulatory cascade and cytokine profile. ACE2 is a crucial component of the renin-angiotensin system (RAS) and the key factor of entry in the cells by the new SARS-CoV-2. ACE2 is widely distributed in the lung and kidneys, and interestingly has a great distribution in the oral cavity, principally in the tongue and periodontal tissue. ACE2 in periodontal tissue plays a crucial role between health and disease. Moreover, the ACE2/Ang-(1-7)/MasR axis is downregulated in the dysbiotic and inflammatory periodontal environment. Nevertheless, the balance of ACE2 activity is modified in the context of concurrent diabetes, increasing the expression of ACE2 by the uncontrolled glycemia chronic in T2DM. Therefore, the uncontrolled hyperglycemia possibly increases the risk of developing periodontitis and triggering overexpression of ACE2 in periodontal tissue of T2DM patients, with these events potentially being essential to SARS-CoV-2 infection and the development of mild-to-severe form of COVID-19. In this sense, we would like to point out that the need for randomized controlled trials is imperative to support this association.

Presence of SARS-CoV-2 and Its Entry Factors in Oral Tissues and Cells: A Systematic Review.

Background and Objectives: The aim of this systematic review is to summarize the current data about the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its entry factors in oral tissues and cells. Materials and Methods: This systematic review was carried out based on the Preferred Reporting Items for a Systematic Review and Meta-Analysis (PRISMA). Three databases were analyzed (Pubmed, Web of science and Scopus) by three independent researchers. From the 18 identified studies, 10 of them met the inclusion criteria. The presence of SARS-CoV-2 or its entry factors (angiotensin-converting enzyme II (ACE2), transmembrane serine proteases (TMPRSS), and furin) was analyzed in these 10 studies during the pandemic. Results: ACE2 expression was analyzed in 9 of the 10 studies. ACE2 is expressed mainly in the tongue, oral mucosa, salivary glands and epithelial cells. The expression of the TMPRSS2 gene or protein was analyzed in 6 studies. These studies reported that the expression of TMPRSS2 was mainly in the salivary glands, tongue, sulcular epithelium and oral mucosa; as well as in cells of the salivary glands (ductal, acinar and myoepithelial cells) and the tongue (the spinous-based cell layer, horny layer and the epithelial surface). Other TMPRSS were also reported. The expression of TMPRSS3, TMPRSS4, TMPRSS5, TMPRSS7 and TMPRSS11D was reported mainly in salivary glands and in epithelial-type cells. Furan expression was analyzed in three studies. The expression of furin was detected mainly in epithelial cells of the tongue. A variety of methods were used to carry out the detection of SARS-CoV-2 or its input molecules. Conclusions: These results show that SARS-CoV-2 can infect a wide variety of oral tissues and cells, and that together with the theories dedicated to explaining the oral symptoms present in SARS-CoV-2 positive patients, it provides us with a good scientific basis for understanding the virus infection in the oral cavity and its consequences.

Saliva: What Dental Practitioners Should Know about the Role of This Biofluid in the Transmission and Diagnostic of SARS-CoV-2.

A novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak has become a global ongoing pandemic. This pandemic represents a great work risk for all health professionals, it includes dental professionals who are in constant contact with saliva, which represents one of the main routes of transmission of the disease. This is due to the fact that a wide variety of oral tissues and cells are susceptible to infection by SARS-CoV-2 and that they express the ACE2 receptor, which is the main route of entry of the virus into cells, as well as the proteins TMPRSS and furin that contributes to the binding of the virus to the host cells. According to recent studies, some of the oral cells most susceptible to infection by SARS-CoV-2 are the epithelial cells of the salivary glands. This explains the presence of the virus in the saliva of infected patients and provides scientific evidence that supports the use of saliva as a biofluid that offers the opportunity to develop new detection and diagnostic techniques. This is because saliva is much easier to collect compared to nasopharyngeal swab. However, the presence of the virus in saliva, also represents a great source of transmission, since the main form of infection is through microscopic drops that are generated when infected people cough or sneeze. Likewise, health professionals, such as dentists are exposed to contagion through saliva. The objective of this review article is to provide a perspective on the main cells and tissues that can be affected by the virus, the risk of contagion that the presence of the virus in saliva represents for dentists; and the new techniques developed from saliva samples for the diagnosis and surveillance of SARS-CoV-2 infection. This review is expected to contribute to the knowledge of oral health professionals about the risk of saliva in the spread of SARS-CoV-2, but also its advantages as a diagnostic tool for pandemic control. In conclusion, the authors can mention that information that provides more scientific evidence of the mechanisms of infection of the coronavirus in oral cells and tissues is being published continually. This also explains the presence of the virus in the saliva of infected people and the risk of contagion that this means. It also provides scientific evidence of the use of saliva as a biofluid for the detection, diagnosis, monitoring, and control of the spread of the virus.

How Dentists Face the COVID-19 in Mexico: A Nationwide Cross-Sectional Study.

Background: on 7 January 2020, a new type of coronavirus was isolated, the Severe Acute Respiratory Syndrome Coronavirus2 (SARS-CoV-2), the organism causing the outbreak that has affected the lives of all humans and has modified the rules of coexistence around the world. In Mexico, from 3 January 2020 to 9 January 2021, there have been 1439, 569 confirmed cases of COVID-19 with 131,031 deaths. The World Health Organization reported that Mexico was ranked twelfth, in terms of confirmed cases of COVID-19 by country. Aim: the objective of this study was to determine what modifications dentists from the Mexican Republic have made to their dental practice during theCOVID-19 pandemic. Methods: the study was conducted based on a questionnaire to evaluate the dentists' response and knowledge on the modifications in their dental practice to combat the new coronavirus's cross-transmission. The questionnaire was piloted before it was distributed. The questionnaire was disseminated through the social network Facebook. The questionnaire was distributed to groups of dentists on Facebook, in each of the Mexican Republic states. The survey was carried out during June 2020. Results and Conclusions: from the 32 states of the Mexican Republic, 29 participated with at least one respondent. The results of the applied survey suggest that dentists, at least the population of surveyed ones, have proper knowledge of detection methods of patients suspected of COVID-19, preventive measures that must be applied in the dental office to decrease the risk of infection, and the appropriate procedures and solutions for dental office disinfection.

Comparison of the retention of conventional dentures after the use of common adhesive brands on poor denture foundations: an in vitro study / Comparación de la retención de dentaduras convencionales con el uso de marcas comerciales de adhesivos en procesos alveolares deficientes: un estudio in vitro

There is no information about the possible impact in denture retention after the use of common denture adhesives (DAs) when poor denture foundations (PDF) are present. Moreover, there is a lack of information about which current formulation provides greater retention and for how long. Twelve models from edentulous patients with different ridge shape and border height were used and complete dentures were manufactured. Four different formulation brands of DAs were tested after 10 minutes and three, six, nine, and 12 hours of DA application using a universal testing machine. The Fittydent® and Fixodent® adhesives had the highest retention at 12 hours. The PDF group increased on average its retention by 400 %. However, the group presented lower retention compared to the good denture foundation group. In conclusion, DAs significantly increased denture retention. The PDF group were the most benefited with the application of DAs. The Fixodent® paste had the highest retention.

No existe información acerca del posible impacto en la retención de dentaduras después del uso de adhesivos dentales comunes (DAs) cuando existen rebordes alveolares deficientes (PDF). Más aun, existe una falta de información acerca de cuál formula actual provee mayor retención y por cuanto tiempo. Doce modelos de pacientes edentulos con diferentes formas y alturas en sus rebordes alveolares fueron usados, y dentaduras completas les fueron realizadas. Cuatro diferentes fórmulas y marcas de DAs fueron evaluadas después de 10 minutos, tres, seis, nueve y 12 horas de que se aplicó el DA usando una maquina universal de pruebas. Los adhesivos Fittydent® y Fixodent® presentaron la retención más alta a las 12 horas. El grupo con PDF incrementó su retención hasta en un 400 %. Sin embargo, el grupo presentó menor retención cuando se comparó con el grupo que posee adecuados procesos alveolares. Los DAs incrementaron significativamente la retención de las dentaduras. El grupo PDF fue el más beneficiado con la aplicación de DAs. La pasta Fixodent® provee la más alta retención.