Impact of the COVID-19 Pandemic on Radiation Oncology Departments in Brazil.

Purpose: The COVID-19 pandemic brought several challenges to cancer practice, especially in ensuring continuity of treatment during this period while minimizing the risks of transmission to a vulnerable population. For radiation oncology departments in Brazil, this contingency has become even more complex owing to the significant effect observed in different sectors of society and the large number of COVID-19 cases and deaths. This study estimated the effect of the COVID-19 pandemic on Brazilian radiation oncology departments and the coping measures used in the country. Methods and Materials: The Brazilian Radiotherapy Society developed a questionnaire, with 14 questions, that were sent to all heads of radiation oncology departments in the country between May and June 2020. These data were evaluated regarding cases confirmed and deaths by COVID-19 in epidemiologic week 28, on July 11, 2020. Results: One hundred twenty-six questionnaires from different regions were answered, representing 44% of the country's services. A drop in the number of patients was observed in 61% of services. This drop was observed both in patients from the public and supplementary private health insurance systems. Regarding patients and employees with COVID-19, we observed that services that primarily treat Unified Health System patients reported significantly fewer cases of the disease. About half of the services had collaborators and patients during radiation therapy with a positive diagnosis of COVID-19. Among the coping measures, the services used intensified hygiene and cleanliness practices, interpersonal distancing, restrictions on access to companions, and other changes in daily practice. Conclusions: Thus, there was an important drop in the number of radiation therapy patients in the country during the pandemic, and this effect was similar among the services, regardless of the characteristics of the patients and the departments' coping measures adopted during the pandemic.

Avaliação da influência das soluções irrigadoras endodônticas na resistência adesiva sobre a dentina superficial coronária de dentes bovinos analisadas em microscópio eletrônico de varredura / Evaluation the influence of endodontic irrigants on bond strength to superficial dentin of bovine teeth and scanning electron microscope analysis

Objetivo: avaliar a influência que as principais soluções irrigadoras endodônticas exercem na resistência adesiva à tração de restaurações adesivas realizadas na dentina superficial coronária de dentes bovinos, e depois de realizados os testes analisar as superfícies dentinárias em MEV. Material e Método: Foram selecionados 48 dentes incisivos bovinos, que tiveram as coroas seccionadas na porção cervical a 2mm da junção amelocementária, e inclusas em resina epóxi. O esmalte da face vestibular dos dentes foi desgastado com lixas d’água acopladas à máquina politriz para exposição da área de dentina a ser avaliada, e os grupos experimentais foram divididos em grupos, de acordo com substâncias irrigadoras utilizadas no tratamento dos espécimes: G1 – Soro fisiológico 0,9% NaCl (controle), G2 – Clorexidina líquida a 2%, G3 – Hipoclorito de sódio a 2,5%, G4 – Hipoclorito de sódio a 1%. Após o tratamento dos espécimes com as soluções irrigadoras e aplicação do material restaurador, foram realizados os testes de tração na máquina de ensaio universal EMIC®, e após o teste foi selecionado um corpo de prova de cada grupo para análise em MEV para avaliação do tipo de fratura ocorrida. Resultados: os resultados médios e desvio padrão obtidos foram: G1=14,52 MPa (11,02); G2=17,96 MPa (7,64); G3=15,61 MPa (9,30); G4=19,24 MPa (5,92). Conclusões: com base na metodologia empregada podemos concluir que não houve diferença estatística entre os valores de força de adesão obtidos após o tratamento das superfícies dentinárias. A análise em MEV demonstrou fraturas mistas, onde há o envolvimento da interface (camada híbrida) ou mais de um substrato (fratura coesiva em resina, fratura coesiva em dentina).

Aim: The aim of this study was to evaluate the influence of endodontic irrigants on tensile bond strength of adhesive restorations made on coronal surfaces of bovine teeth and after tests to analyze the dentin surfaces by SEM. Methodology: Forty eight bovine incisors teeth were selected. The teeth have crowns split in the cervical portion to 2mm from the junction amelo-cementum, and were included in epoxi resin. The enamel vestibular faces of the teeth were worn for exposure the area of dentin to be evaluated. The experimental groups were divided according to the solution used: G1- 0,9% NaCl, G2- 2% chlorhexidine solution; G3- 2,5% NaOCl; G4- 1% NaOCl.. Results: the results and the standard deviation were: G1=14,52 MPa (11,02); G2=17,96 (7,64); G3=15,61 (9,30); G4=19,24 (5,92). Conclusions: Under the conditions of this study it can be concluded that there were no statistically significant differences among the groups. SEM analysis showed mixed fractures, where there is involvement of the interface (hybrid layer) or over a substrate (cohesive failure in resin, cohesive failure in dentin).