Nanotechnology and COVID-19: quo vadis?

The pandemic COVID-19 has worried everyone due to the high mortality rate and the high number of people hospitalized with severe acute respiratory syndrome caused by SARS-CoV-2. Given the seriousness of this disease, several companies and research institutions have sought alternative treatment and/or prevention methods for COVID-19. Due to its versatility, nanotechnology has allowed the development of protective equipment and vaccines to prevent the disease and reduce the number of severe COVID-19 cases. Thus, this article combined the main works and products developed in a nanotechnological field for COVID-19. We performed a literature search using the keywords "COVID-19," "SARS-CoV-2," "nanoparticles," "nanotechnology," and "liposomes" in the SciELO, Scifinder, PubMed, Sciencedirect, ClinicalTrials, and Nanotechnology Products databases Database. The data survey indicated 48 articles, 62 products, and 32 patents. The use of nanotechnology against COVID-19 has brought benefits in several parameters of this disease, helping develop rapid diagnostic tests that release the result in 10 min, as well as developing vaccines containing genetic material from SARS-CoV-2 (DNA, mRNA, and protein subunits). Nanotechnology is an exceptional ally against COVID-19, contributing to the most diverse areas, helping both prevent, diagnose, and treat COVID-19.

COVID-19 vaccine effectiveness against laboratory confirmed symptomatic SARS-CoV-2 infection, COVID-19 related hospitalizations and deaths, among individuals aged 65 years or more in Portugal: a cohort study based on data-linkage of national registries February-September 2021

BackgroundUsing data from electronic health registries, this study intended to estimate the COVID-19 vaccine effectiveness in the population aged 65 years and more, against symptomatic infection, COVID-19 related hospitalizations and deaths, overall and by time since complete vaccination. MethodsWe stablished a cohort of individuals aged 65 and more years old, resident in Portugal mainland, using the National Health Service unique identifier User number to link eight electronic health registries. Outcomes included were symptomatic SARS-CoV-2 infections, COVID-19 related hospitalizations or deaths. The exposures of interest were the mRNA vaccines (Cominarty or Spikevax) and the viral vector Vaxzevria vaccine. Complete scheme vaccine effectiveness (VE) was estimated as one minus the confounder adjusted hazard ratio, for each outcome, estimated by time-dependent Cox regression with time dependent vaccine exposure. ResultsFor the cohort of individuals aged 65-79 years, complete scheme VE against symptomatic infection varied between 43% (Vaxzevria) and 65% (mRNA vaccines). This estimate was slightly lower in the [≥]80 year cohort (53% for mRNA vaccines. VE against COVID-19 hospitalization varied between 89% (95%CI: 52-94) for Vaxzevria and 95% (95%CI: 93-97) for mRNA vaccines for the cohort aged 65-79 years and was 76% (95%CI: 67-83) for mRNA vaccines in the [≥]80 year cohort. High VE against COVID-19 related deaths were estimated, for both vaccine types, 95% and 81% for the 65-79 years and the [≥]80 year cohort, respectively. We observed a significant waning of VE against symptomatic infection, with VE estimates reaching approximately 34% for both vaccine types and cohorts. Significant waning was observed for the COVID-19 hospitalizations in the [≥]80 year cohort (decay from 83% 14-41 days to 63% 124 days after mRNA second dose). No significant waning effect was observed for COVID-19 related deaths in the period of follow-up of either cohorts. ConclusionsIn a population with a high risk of SARS-CoV-2 complications, we observed higher overall VE estimates against more severe outcomes for both age cohorts when compared to symptomatic infections. Considering the analysis of VE according to time since complete vaccination, the results showed a waning effect for both age cohorts in symptomatic infection and COVID-19 hospitalization for the 80 and more yo cohort.

mRNA vaccines effectiveness against COVID-19 hospitalizations and deaths in older adults: a cohort study based on data-linkage of national health registries in Portugal

BackgroundWe used electronic health registries to estimate the mRNA vaccine effectiveness (VE) against COVID-19 hospitalizations and deaths in older adults. MethodsWe established a cohort of individuals aged 65 and more years, resident in Portugal mainland through data linkage of eight national health registries. For each outcome, VE was computed as one minus the confounder-adjusted hazard ratio, estimated by time-dependent Cox regression. ResultsVE against COVID-19 hospitalization [≥]14 days after the second dose was 94% (95%CI 88 to 97) for age-group 65-79 years old (yo) and 82% (95%CI 72 to 89) for [≥]80 yo. VE against COVID-19 related deaths [≥] 14 days after second dose was 96% (95%CI 92 to 98) for age-group 65-79 yo and 81% (95%CI 74 to 87), for [≥]80 yo individuals. No evidence of VE waning was observed after 98 days of second dose uptake. ConclusionsmRNA vaccine effectiveness was high for the prevention of hospitalizations and deaths in age-group 65-79 yo and [≥]80 yo with a complete vaccination scheme, even after 98 days of second dose uptake.

Direct-Indirect Technique Restoration for Non-Carious Cervical Lesions Treatment: a Case Report / Técnica Direta-Indireta para Restauração de Lesões Cervicais não Cariosas: um Relato de Caso

Non-Carious Cervical Lesions are characterized by slow and progressive loss of hard tissue at the level of enamel-cement junction, without bacterial involvement. This work aimed to address a case report of restorative treatment in Class V cavities in multiple premolars using the directindirect technique with composite resin. A 42 year-old male patient presented for esthetic restorative treatment with the complaint of severe dentin hypersensitivity and wedged-shaped non-carious cervical lesions affecting the maxillary premolars. The restorative treatment chosen was a direct-indirect technique with composite performed into three sessions as follows: making the class V composite inlays, cementation, and final polishing. The direct-indirect technique as an alternative to the traditional direct technique has the benefits of a better contour of the restoration, since the finishing and polishing are made extraorally. Besides, the control of the polymerization stress and less discomfort to the patient are other advantages. In the case of direct-indirect class V restoration, the advantages far surpass those of the direct technique. (AU)

As Lesões Cervicais Não Cariosas se caracterizam pela perda lenta e progressiva de tecido duro próximo a junção cemento-esmalte, sem envolvimento bacteriano. Este trabalho tem o objetivo de relatar um caso clínico de tratamento restaurador em cavidades do tipo Classe V em pré-molares pela técnica direta-indireta com resina composta. Paciente do sexo masculino, 42 anos, queixava-se de forte sensibilidade e múltiplas Lesões Cervicais Não Cariosas na forma de cunha nos pré-molares superiores. O tratamento restaurador escolhido foi a técnica direta-indireta com resina composta realizado em três sessões distribuídas em confecção da peça em resina composta, cimentação e polimento final. A técnica direta-indireta surge como alternativa a técnica direta tradicional trazendo como benefícios um melhor contorno da restauração, uma vez que esta é acabada e polida fora da boca, além do controle do estresse de polimerização e menor desconforto ao paciente. A intervenção restauradora direta-indireta se mostra eficaz devido ao fato de conseguir contornar dificuldades encontradas em técnicas restauradoras diretas. (AU)

Association Between In-Office And At-Home Tooth Bleaching: A Single Blind Randomized Clinical Trial.

This controlled randomized clinical trial evaluated the effect of associating at-home and in-office bleaching procedures on tooth sensitivity (TS) and bleaching effectiveness. Forty patients subjected to on session of in-office bleaching with 38% peroxide hydrogen. Subsequently, the patients were randomly allocated to receive a second session of in-office bleaching or to use a tray containing 10% carbamide peroxide delivered during 7 consecutive days. The worst TS score reported during or after each bleaching procedure was recorded using a verbal rating scale and TS risk (score different from 0) was calculated. Color changes were measured 7 days after each in-office session (for patients receiving in-office procedures only) or after the end of at-home bleaching (for the combined protocol), and 6 months after the last procedure for both bleaching protocols. Color was assessed by a spectrophotometer and by color match with the Vita Classical and Bleach guide scales. Statistical analyses were carried out to assess possible differences between the protocols regarding the outcomes and to analyze the effect of time of assessment on color changes. The bleaching protocol did not affect the risk for and the maximum level of TS reported, irrespective of the time of assessment. In the color evaluation, the bleaching protocol also did not affect the ultimate tooth color. In conclusion, after one in-office bleaching session, there was no difference in bleaching effectiveness and TS between performing a second in-office session and associating it with 1-week at-home bleaching.

Association between in-office and at-home tooth bleaching: a single blind randomized clinical trial

Abstract This controlled randomized clinical trial evaluated the effect of associating at-home and in-office bleaching procedures on tooth sensitivity (TS) and bleaching effectiveness. Forty patients subjected to on session of in-office bleaching with 38% peroxide hydrogen. Subsequently, the patients were randomly allocated to receive a second session of in-office bleaching or to use a tray containing 10% carbamide peroxide delivered during 7 consecutive days. The worst TS score reported during or after each bleaching procedure was recorded using a verbal rating scale and TS risk (score different from 0) was calculated. Color changes were measured 7 days after each in-office session (for patients receiving in-office procedures only) or after the end of at-home bleaching (for the combined protocol), and 6 months after the last procedure for both bleaching protocols. Color was assessed by a spectrophotometer and by color match with the Vita Classical and Bleach guide scales. Statistical analyses were carried out to assess possible differences between the protocols regarding the outcomes and to analyze the effect of time of assessment on color changes. The bleaching protocol did not affect the risk for and the maximum level of TS reported, irrespective of the time of assessment. In the color evaluation, the bleaching protocol also did not affect the ultimate tooth color. In conclusion, after one in-office bleaching session, there was no difference in bleaching effectiveness and TS between performing a second in-office session and associating it with 1-week at-home bleaching.

Resumo Este ensaio clínico controlado e randomizado avaliou o efeito da associação de procedimentos de clareamento caseiro e de consultório na sensibilidade dental (SD) e efetividade clareadora. Quarenta pacientes receberam uma sessão de clareamento de consultório com peróxido de hidrogênio a 38%. Em seguida, os pacientes foram aleatoriamente alocados para receberem uma segunda sessão de clareamento de consultório ou para usar uma moldeira com peróxido de carbamida a 10% por 7 dias consecutivos. O pior score de SD relatada durante ou após cada procedimento clareador foi mensurado usando uma escala verbal, e o risco a SD (escore diferente de 0) foi calculado. Mudança de cor foi mensurada 7 dias após cada sessão de clareamento de consultório (para paciente submetidos a apenas procedimentos de consultório) ou após o fim do clareamento de caseiro (para o protocolo combinado) e 6 meses após o último procedimento clareador para os dois protocolos de clareamento. A cor foi mensurada através de um espectrofotômetro e pelo uso das escalas Vita Clássica e Bleach guide. As análises estatísticas foram realizadas para verificar possíveis diferenças em relação aos desfechos e para analisar o efeito do momento da mensuração nas mudanças de cor. O protocolo clareador não afetou o risco e o nível máximo de SD relatado, independentemente do tempo de avaliação. Na avaliação de cor, o protocolo clareador também não afetou a cor final dos dentes. Como conclusão, após uma sessão de clareamento de consultório, não há diferença na efetividade clareadora e na SD em realizar uma segunda sessão de consultório ou associá-la com uma semana de clareamento caseiro.

Vein of Galen Aneurysmal Malformation with Transvenous Endovascular Treatment in an Adult: Case Report

Vein of Galen aneurysmal malformation (VGAM) is the result of the direct communication between the arterial network and the median prosencephalic vein. It is a rare vascular congenital malformation representing less than 1% of intracranial abnormalities. This finding is very rare in adults, and it may or may not present symptoms during childhood. Most cases of VGAM can be detected in the fetus by ultrasonography. The referral of pregnant women with fetuses with this condition to centers where better facilities and resources for childbirth and immediate postpartum care are available has resulted in considerable improvement in the prognosis of newborns. Regarding treatment, the endovascular approach to VGAM includes arterial embolization and percutaneous transvenous techniques. The transvenous endovascular treatment was chosen in the case presented in this article.

A malformação aneurismática da veia de Galeno (MAVG) é resultado da comunicação direta entre a rede arterial e a veia prosencefálica mediana. Trata-se de uma malformação vascular congênita rara, que representa menos de 1% das anormalidades intracranianas. Sua ocorrência é muito rara em adultos, e a malformação pode ou não apresentar sintomas durante a infância. A maioria dos casos pode ser detectada em fetos por ultrassonografia. O encaminhamento de grávidas com fetos com esta malformação para centros mais bem estruturados, com recursos para cuidados no parto e pós-parto, tem resultado em considerável melhora do prognóstico de recémnascidos. Quanto ao tratamento, o acesso endovascular à MAVG inclui a técnica de embolização arterial e o tratamento transvenoso percutâneo. O tratamento transvenoso endovascular foi escolhido no caso apresentado neste artigo.

Região posterior da maxila: atualizando conceitos anatômicos com o avanço da tecnologia de superfícies. Relato de caso clínico / The posterior maxilla: An update of anatomical notions based on advances in endosseousimplant surface technology. A case report

Objetivo: desde o início da especialidade Implantodontia, o tratamento reabilitador por meio de implantes na região posterior de maxila foi considerado um grande desafio para o profissional. As limitações das técnicas e materiais empregados geraram conceitos errôneos, principalmente quanto às definições de classificações ósseas, criando um conceito de osso pobre, que condizia com o nível elevado de insucessos de tratamentos realizados com superfícies de implantes pouco evoluídas. Revisando a literatura a respeito da origem embriológica tecidual da maxila e sua anatomia, observa-se a grande capacidade regenerativa de ossos medulares que são ricos em células mesenquimais. Métodos: destaca-se, nesse relato de caso clínico, a falha de um implante de superfície maquinada, fixado por técnica de osteotomia em região de primeiro molar de maxila, que foi substituído por implante de superfície SLA (sand-blasted, large-grit, acid-etched), com acompanhamento de taxa de sobrevivência de cinco anos. Resultados: avaliações clínica e radiográfica, em períodos de revisão semestral, foram realizadas, demonstrando a estabilidade de osseointegração do implante e a biocompatibilidade tecidual, além da funcionalidade da prótese realizada. Conclusão: em associação à vasta literatura científica que mostra a evolução tecnológica das superfícies de implantes que estimulam a transformação das células mesenquimais em osteoblastos, gerando, com isso, a osseointegração em períodos curtos de tempo, podemos sugerir que a região posterior de maxila se transforma em uma proposta previsível e segura de reabilitação por implantes.

Objective: Fixed implant-supported rehabilitation of the posterior maxilla is a challenge to dental professionals. Limitationsof technique and material have established wrong concepts, especially with regard to bone classification. Forinstance, the concept of poor-quality bone has been associated with high rates of therapeutic failure because of implantswith poorly evolved surfaces. A literature review on the embryological origin of tissues and the anatomy of the maxillahighlight the high regenerative ability of trabecular bone, which is rich in mesenchymal cells. Methods: The presentreport describes a case of failure of a machined-surface implant placed by osteotomy at the maxillary first molar region.The implant was replaced by a sandblasted, large grit, acid-etched SLA surface with a six-year survival rate follow-up.Clinical and radiographic assessments were performed every six months. Results: Data revealed implant osseointegrationstability as well as tissue biocompatibility and prosthetic functionality. Conclusion: The literature on technicallyadvanced implant surfaces suggests that the posterior maxilla is a safe and predictable site for fixed implant-supportedrehabilitation.

Dentin deproteinization effect on bond strength of self-adhesive resin cements

This study examined the effect of deproteinization on the bond strength between self-adhesive resin cements and dentin surfaces that were untreated (control), acid-etched, or acid-etched and subjected to a post-etch deproteinization treatment. Cylinders of RelyX Unicem or BisCem (n = 6) cement were build-up on the dentin surfaces and tested to determine shear strength. The results were analyzed using two-way ANOVA and Tukey's test (5%). While neither dentin pretreatment improved the bond strength for RelyX Unicem, deproteinization treatments resulted in greater bond strength in BisCem specimens while acid etching alone did not improve the performance of the material.

Dentin deproteinization effect on bond strength of self-adhesive resin cements.

This study examined the effect of deproteinization on the bond strength between self-adhesive resin cements and dentin surfaces that were untreated (control), acid-etched, or acid-etched and subjected to a post-etch deproteinization treatment. Cylinders of RelyX Unicem or BisCem (n = 6) cement were build-up on the dentin surfaces and tested to determine shear strength. The results were analyzed using two-way ANOVA and Tukey's test (5%). While neither dentin pretreatment improved the bond strength for RelyX Unicem, deproteinization treatments resulted in greater bond strength in BisCem specimens while acid etching alone did not improve the performance of the material.

Influência da marca do condicionador ácido na resistência de união da resina composta à dentina / Influence of acid etchant brand on bond strength of composite resin to dentin

Introdução: Apesar da importância da etapa de condicionamento ácido nos procedimentos adesivos, pouco se sabe sobre o efeito da marca do condicionador ácido sobre a união do adesivo à dentina. Objetivo: Este estudo avaliou o efeito de diferentes condicionadores ácidos na união da resina composta à dentina. Material e Método: Vinte e cinco incisivos bovinos tiveram a coroa dividida em duas hemissecções. As superfícies vestibulares foram desgastadas com lixa carbeto de silício (SiC) #180 até a exposição de dentina, seguida por lixas SiC #600 para padronização da smear layer. As amostras foram aleatoriamente alocadas em cinco grupos (n = 10), de acordo com marca do condicionador ácido: 3M ESPE, Ultradent, Dentsply, Villevie e DFL. Apenas um sistema de união convencional de dois passos (Ambar, FGM) foi utilizado. Matrizes de silicone foram utilizadas na confecção de três cilindros de resina composta em cada amostra. Após 24 horas, os cilindros foram testados sob carga de cisalhamento até a falha. Os dados foram analisados com ANOVA a um critério e teste de Tukey (α = 0,05). O modo de falha foi avaliado em microscopia óptica e os dados submetidos ao Teste Qui-quadrado (α = 0,05). Resultado: Não houve diferença estatística na resistência de união obtida entre os condicionadores ácidos avaliados. Houve predomínio de falhas adesivas, exceto para os condicionadores da Dentsply e DFL, que demonstraram similaridade entre falhas adesivas e mistas. Conclusão: As diferentes marcas de condicionadores ácidos avaliados não influenciaram a resistência de união de resina composta à dentina.

Introduction: Despite the importance of the acid etching step on bonding procedures, little is known about the acid etchant brand effect on bond strength of adhesive to dentin. Objective: The aim of this study was to evaluate the effect of different acid etchants at the bond strength of composite resin to dentine. Material and Method: Twenty five bovine incisors had their crown sectioned in two hemi-sections. The buccal surfaces were grounded with #180 silicon carbide (SiC) abrasive paper to exposure of dentin, followed by #600 SiC paper to standardize the smear layer. The samples were randomly allocated into five groups (n = 10) according to acid etchant brands: 3M ESPE, Ultradent, Dentsply, Villevie and DFL.Only a two-step etch-and-rinse adhesive system (Ambar, FGM) was used. Silicon molds were used to build-up three resin composite cylinder per sample. After 24 hours, cylinders were submitted to shear load until the failure. Data were analyzed by one way ANOVA and Tukey`s test (α = 0,05). The failure mode was evaluated under optical microscopy and the data were submitted to Chi-square test (α = 0,05). Result: There was no statistical difference on bond strength obtained between the acid etchants evaluated. There was predominance of adhesive failures, except for etchants of Dentsply and DFL that showed similarity between mixed and adhesive failures. Conclusion: Different brands of acid etchants did not influence on the bond strength of composite resin to dentin.

Inhibition of activin/nodal signalling is necessary for pancreatic differentiation of human pluripotent stem cells.

AIMS/HYPOTHESIS: Human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hIPSCs) offer unique opportunities for regenerative medicine and for the study of mammalian development. However, developing methods to differentiate hESCs/hIPSCs into specific cell types following a natural pathway of development remains a major challenge. METHODS: We used defined culture media to identify signalling pathways controlling the differentiation of hESCs/hIPSCs into pancreatic or hepatic progenitors. This approach avoids the use of feeders, stroma cells or serum, all of which can interfere with experimental outcomes and could preclude future clinical applications. RESULTS: This study reveals, for the first time, that activin/TGF-ß signalling blocks pancreatic specification induced by retinoic acid while promoting hepatic specification in combination with bone morphogenetic protein and fibroblast growth factor. Using this knowledge, we developed culture systems to differentiate human pluripotent stem cells into near homogenous population of pancreatic and hepatic progenitors displaying functional characteristics specific to their natural counterparts. Finally, functional experiments showed that activin/TGF-ß signalling achieves this essential function by controlling the levels of transcription factors necessary for liver and pancreatic development, such as HEX and HLXB9. CONCLUSION/INTERPRETATION: Our methods of differentiation provide an advantageous system to model early human endoderm development in vitro, and also represent an important step towards the generation of pancreatic and hepatic cells for clinical applications.

Eficácia de um programa de dança para prevenir quedas entre idosos / Efficacy of a dance program in preventing falls among the elderly

s quedas e as fraturas influenciam na capacidade funcional dos idosos. O objetivo deste trabalho foi verificar a eficácia de um programa de dança para diminuir a incidência de quedas entre idosos e melhorar suas próprias avaliações subjetivas de saúde. O desenho metodológico foi um ensaio clínico controlado. A amostra incluiu 30 mulheres maiores de 60 anos, de nível socioeconômico baixo, moradoras de uma área central da cidade de Salvador, Bahia, Brasil. Não foram verificadas diferenças significativas entre os grupos em relação à incidência de quedas nem às avaliações subjetivas de saúde. Conclusivamente, encontrou-se que, para desenvolver ações destinadas a reduzir o risco de quedas, deve-se contemplar uma abordagem multidimensional do problema e não apenas observar os determinantes ligados à saúde física do indivíduo.