Coronavirus disease (COVID-19) complicated by rhino-orbital-cerebral mucormycosis presenting with neurovascular thrombosis: a case report and review of literature.

Among the ever-increasing literature of the coronavirus disease 2019 (COVID-19), there have been reports on several complications in association with severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), such as secondary bacterial and fungal infections. We report a 61-year-old woman with a past history of diabetes mellitus who presented to our hospital suffering from COVID-19 infection. During the course of her hospitalization, the patient developed chemosis and proptosis in both eyes, ultimately leading to a diagnosis of invasive rhino-orbital-cerebral mucormycosis and cerebrovascular thrombosis. This study strengthens the possible association between the occurrence of COVID-19 and invasive mucormycosis infection, providing new impetus for further investigations to substantiate this correlation.

Cerebral venous sinus thrombosis associated with COVID-19: a case series and literature review.

BACKGROUND: Since the emergence of COVID-19 pandemic, several cases of cerebral venous sinus thrombosis (CVST) have been reported in SARS-CoV-2 infected individuals. METHODS: Consecutive patients with documented SARS-CoV-2 infection, as well as clinical and radiological characteristics of CVST, were reported from three teaching hospitals in the South West, North West, and the center of Iran between June and July 2020. We also searched the abstract archives until the end of August 2020 and gathered 28 reported cases. The diagnostic criteria for SARS-CoV-2 infection were determined according to SARS-CoV-2 detection in oropharyngeal or nasopharyngeal samples in clinically suspected patients. Demographics, prominent COVID-19 symptoms, confirmatory tests for SARS-CoV-2 infection diagnosis, the interval between the diagnosis of SARS-CoV-2 infection and CVST, clinical and radiological features of CVST, therapeutic strategies, CVST outcomes, rate of hemorrhagic transformation, and mortality rate were investigated. RESULTS: Six patients (31-62 years-old) with confirmed CVST and SARS-CoV-2 infection were admitted to our centers. Four patients had no respiratory symptoms of SARS-CoV-2 infection. Five patients developed the clinical manifestations of CVST and SARS-CoV-2 infection simultaneously. Three patients had known predisposing factors for CVST. Despite receiving CVST and SARS-CoV-2 infection treatments, four patients died. SARS-COV-2 associated CVST patients were older (49.26 vs. 37.77 years-old), had lower female/male ratio (1.42 vs. 2.19), and higher mortality rate (35.29% vs. 6.07%) than CVST not associated with COVID-19. CONCLUSIONS: The role of SARS-CoV-2 as a "cause" versus an "additive contributor" remains to be elucidated. Practitioners should be aware of the possibility of CVST in SARS-CoV-2 infection.

Effect of TiO2 nanoparticles incorporation on antibacterial properties and shear bond strength of dental composite used in Orthodontics.

INTRODUCTION: Plaque accumulation and bond failure are drawbacks of orthodontic treatment, which requires composite for bonding of brackets. As the antimicrobial properties of TiO2 nanoparticles (NPs) have been proven, the aim of this study was to evaluate the antimicrobial and mechanical properties of composite resins modified by the addition of TiO2 NPs. METHODS: Orthodontics composite containing 0%, 1%, 5% and 10% NPs were prepared. 180 composite disks were prepared for elution test, disk agar diffusion test and biofilm inhibition test to collect the counts of microorganisms on three days, measure the inhibition diameter and quantify the viable counts of colonies consequently. For shear bond strength (SBS) test, 48 intact bovine incisors were divided into four groups. Composites containing 0%, 1%, 5% and 10% NPs were used for bonding of bracket. The bracket/tooth SBS was measured by using an universal testing machine. RESULTS: All concentration of TiO2 NPs had a significant effect on creation and extension of inhibition zone. For S. mutans and S. sanguinis, all concentration of TiO2 NPs caused reduction of the colony counts. Composite containing 10% TiO2 NPs had significant effect on reduction of colony counts for S. mutans and S. sanguinis in all three days. The highest mean shear bond strength belonged to the control group, while the lowest value was seen in 10% NPs composite. CONCLUSIONS: Incorporating TiO2 nanoparticles into composite resins confer antibacterial properties to adhesives, while the mean shear bond of composite containing 1% and 5% NPs still in an acceptable range.

Effect of TiO2 nanoparticles incorporation on antibacterial properties and shear bond strength of dental composite used in Orthodontics

ABSTRACT Introduction: Plaque accumulation and bond failure are drawbacks of orthodontic treatment, which requires composite for bonding of brackets. As the antimicrobial properties of TiO2 nanoparticles (NPs) have been proven, the aim of this study was to evaluate the antimicrobial and mechanical properties of composite resins modified by the addition of TiO2 NPs. Methods: Orthodontics composite containing 0%, 1%, 5% and 10% NPs were prepared. 180 composite disks were prepared for elution test, disk agar diffusion test and biofilm inhibition test to collect the counts of microorganisms on three days, measure the inhibition diameter and quantify the viable counts of colonies consequently. For shear bond strength (SBS) test, 48 intact bovine incisors were divided into four groups. Composites containing 0%, 1%, 5% and 10% NPs were used for bonding of bracket. The bracket/tooth SBS was measured by using an universal testing machine. Results: All concentration of TiO2 NPs had a significant effect on creation and extension of inhibition zone. For S. mutans and S. sanguinis, all concentration of TiO2 NPs caused reduction of the colony counts. Composite containing 10% TiO2 NPs had significant effect on reduction of colony counts for S. mutans and S. sanguinis in all three days. The highest mean shear bond strength belonged to the control group, while the lowest value was seen in 10% NPs composite. Conclusions: Incorporating TiO2 nanoparticles into composite resins confer antibacterial properties to adhesives, while the mean shear bond of composite containing 1% and 5% NPs still in an acceptable range.

RESUMO Introdução: o acúmulo de placa e as descolagens de braquetes são algumas desvantagens presentes no tratamento ortodôntico, no qual se requer o uso de materiais compósitos para a colagem dos braquetes. Objetivo: tendo em vista que as propriedades antimicrobianas das nanopartículas (NPs) de TiO2 já foram confirmadas, o objetivo do presente estudo foi avaliar as propriedades antimicrobianas e mecânicas de resinas compostas modificadas pela adição de NPs de TiO2. Métodos: compósitos ortodônticos contendo 0%, 1%, 5% e 10% de NPs foram preparados. Cento e oitenta discos de compósito foram preparados para o teste de eluição, o ensaio de difusão em ágar por disco, e o ensaio de inibição da formação de biofilme, para se calcular as contagens de microrganismos ao longo de três dias, medir o diâmetro da inibição e, consequentemente, quantificar as contagens de colônias viáveis. Para o teste de resistência da colagem ao cisalhamento (SBS), 48 incisivos bovinos intactos foram divididos em quatro grupos, nos quais os compósitos contendo 0%, 1%, 5% e 10% de NPs foram utilizados para colagem dos braquetes. A SBS da interface braquete/dente foi medida em uma máquina universal de ensaios. Resultados: todas as concentrações de NPs de TiO2 apresentaram efeito significativo na formação e na extensão da zona de inibição. Para o S. mutans e o S. sanguinis, todas as concentrações de NPs de TiO2 causaram redução na contagem das colônias. O compósito contendo 10% de NPs de TiO2 apresentou uma diminuição significativa na contagem de colônias de S. mutans e S. sanguinis durante os três dias. A média mais alta da SBS foi observada no grupo controle, enquanto o valor mais baixo foi observado para o compósito com 10% de NPs. Conclusões: a incorporação de nanopartículas de TiO2 nas resinas compostas lhes conferiu propriedades antibacterianas, e o valor médio da SBS das resinas contendo 1% e 5% de NPs apresentou-se dentro de uma faixa aceitável.