ABSTRACT
Disorganizations due to the current coronavirus SARS-CoV-2 pandemic that have required a national quarantine from the 17th of march to the 11 of May 2020, mangle and question. In view of the situation's extreme traumatic character and of the pathological consequences observed, we are going to try to give meaning to an almost chaotic situation. Our shared production, coming out of two psychologists - one being in quarantine and the other one not - crossed diary trying to put the theory in favor of the clinic, has for aim to build a support structuring thought. In fact, the breaking of COVID-19's death anxiety creates hysterical looking defense mechanisms within the entire society. When the extreme and sudden situation that we are describing can be understood as a paradoxical injunction as much as a denial of the split, we will focus our analyzes on both societal and hospital realities, that seems to jeopardize humanity, dignity, solidarity, equity, justice and autonomy principles. Describing, trying to put into words and analyzing all movements concerning the current situation, could lead to giving meaning to a situation which seems already deprived.
ABSTRACT
Dental pulp stem cells (DPSCs) are stem cells found in the dental pulp. The ability of DPSCs to differentiate towards odontoblastic and osteoblastic phenotype was reported first in the literature, then in the following years, numerous studies on odontogenesis were carried out, starting from mesenchymal stem cells isolated from tissues of dental and oral origin. The aim of this research was to evaluate the behaviour of DPSCs grown on silicon nanoporous and mesoporous matrices and differentiated towards the osteogenic phenotype, but also to investigate the use of DPSCs in pilot studies focused on the biological compatibility of innovative dental biomaterials. Twenty-eight silicon samples were created with standardized procedures. These scaffolds were divided into samples made of silicon bulk, nanoporous silicon, mesoporous silicon, nanoporous silicon functionalized with (3-Aminopropyl) Trimethoxysilane (APTMS) and methanol (MeOH), nanoporous silicon functionalized with (3-Aminopropyl) Trimethoxysilane (APTMS)/toluene, mesoporous silicon functionalized with (3-Aminopropyl) Trimethoxysilane (APTMS) and methanol (MeOH) andmesoporous silicon functionalized with (3-Aminopropyl) Trimethoxysilane (APTMS)/toluene. DPSC proliferation on the tested silicon scaffolds was analyzed at 3 and 5 days. The assay showed that DPSCs proliferated better on mesoporous scaffolds functionalized with APTMS/toluene compared to a silicon one. These results show that the functionalization of silicon scaffold with APTMS/toluene supports the growth of DPSCs and could be used for future applications in tissue engineering.
Subject(s)
Dental Pulp/cytology , Stem Cells/cytology , Tissue Scaffolds , Adult , Cell Differentiation , Cell Proliferation , Cells, Cultured , Humans , Nanostructures , Porosity , Silicon , Tissue EngineeringABSTRACT
OBJECTIVES: The fit of implant-supported single-tooth Lava zirconia assemblies was investigated in this study. The implant-abutment interface, the interface between the metallic and the zirconia portion of the abutment and the interface between Lava abutments and copings were evaluated. The adaptation of titanium abutments to implants and Lava copings was investigated as a control. MATERIAL AND METHODS: Twenty implants were randomly assigned and connected to Lava abutments (group 1) or titanium abutments (group 2). All specimens were subjected to scanning electron microscopy (SEM) analysis of the fixture/abutment fit. Afterwards, specimens were luted to Lava copings and subjected to a SEM evaluation of the marginal external adaptation of the abutments with the copings. Finally, the samples were embedded in resin, sectioned and subjected to SEM analysis of the following interfaces; group 1: titanium/zirconia interface (between the constitutive components of the Lava abutment) and the zirconia/zirconia interface (between the Lava abutment and the coping); group 2: the titanium/zirconia interface (between the titanium abutment and the Lava coping). Non-parametric analysis of variance and a post hoc test were used for statistical analysis. RESULTS: Significant differences emerged in the cement thickness between titanium and zirconia components of the Lava abutments as compared with the thickness measured at the interface between Lava copings and the abutments investigated. No differences were found in cement thickness between Lava copings and the two different abutments. CONCLUSIONS: When Lava abutments are used, the most critical cement thickness is the internal interface between its titanium and zirconia components. Lava coping adaptation for both Lava and titanium abutments is within the clinical acceptable range.
