The occurrence and evolution of the disease depend on the properties of the organism, the cortical inhibition prevents the development of anaphylactic shock in humans. In some people, the increased and altered sensitivity manifests itself in the form of idiosyncrasy. In idiosyncrasy, the reactivity of the organism is altered from different substances of antigenic nature These substances can be food (milk, strawberries, eggs) or drug substances (iodine, iodoform, bromine, etc.) (drug idiosyncrasy whose symptoms are not related to the specific pharmacodynamic properties of the substance), plastics (prostheses, babies’dummy, etc.). The allergic reaction can be divided into two successive stages: a first stage of allergy, characterized by the formation of allergic type antibodies, their spread and fixation on certain tissues, and the second stage, of antigen –antibody, which represents the reaction In both stages there are both phases of immunological specificity (antibody production, antigen binding to the antibody) as well as non-specific phases in which the allergen and the antibody behave banal, non-immune (enter the body, circulate) or participate in reactions without immunological specificity (histamine release, etc.) The allergy therapy will appropriately include both specific methods and non-specific methods. Specific methods are only two: stopping the allergen input (allergen deficiency) and specific desensitization.Material and Method: A sample of 183 patients was studied in the present study between 2013 and 2017 with suspicions of hypersensitivity to dental materials for local or general symptoms. Results and discussions: A more severe allergy can be manifested in the dental office, is caused by the local anesthetic. The dentist has several local anesthetics, and through a well-done questioning, he will decide which type of anesthesia is the one indicated. For these reasons, an allergic reaction to the anesthetic is less common, but its manifestations are rather severe if it does not intervene in time. Conclusions:Dental biomaterials, in addition to mechanical and chemical resistance, should not contain toxic diffusible elements in the general circulation, elements with allergic or carcinogenic potential.
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The controlled lamination of thick sheets involves the use of algorithms for choosing the rolling parameters: the initial heating temperature, the lamination scheme (the distribution of the total thickness reduction on each rolling cage, the number of passes through each cage and the distribution of the thickness reduction on each passage, intermediate cooling - cooling time and speed), and the temperature of the product obtained at the end of the rolling. The complexity of the phenomena, which occur during the hot plastic deformation process and which must be sufficiently well mastered in order to obtain reproducibly the technical specifications imposed on the products with different destinations, is the justification for this work. The data provided by Arcelor-Mittal Galati was used to obtain the mathematical model. Equations that correlate the main mechanical characteristics with the chemical composition of the steel and the parameters of the hot rolling pattern used are presented.
The worldwide increasing number of reports related to new cases of Breast Implant-associated Anaplastic Large Cell Lymphoma (BIA-ALCL) raises the interest of the scientific community in understanding the pathophysiology and the prognosis of these patients. This material presents the impact that BIA-ALCL exerts on the reconstructive options for patients who have undergone mastectomy. The research is based on data obtained from the analysis of a group of patients who have undergone 71 surgeries performed within the National Breast Reconstruction Program between 2015 and 2019. The statistical analysis revealed that 35.14% of the patients that were examined during the breast reconstruction consult refused the use of alloplastic techniques by invoking the potential associated risks described in the insufficient documentation of BIA-ALCL pathophysiology. Improving BIA-ALCL detection and reporting systems has led to an accelerated increase in the number of new diagnosed cases, determining the patients’ reticence towards the use of alloplastic reconstructive techniques.
Noninvasive techniques, such as Magnetic Resonance Imaging (MRI) are becoming more used in the study of bone regeneration outcomes, in both animal models and human patients. Many studies have shown the potential of tissue engineering therapies to promote healing of skeletal injuries, but further research is needed to optimize these treatment options. This investigation is a continuation of other previous published studies, in which critical-sized bone defects created in the parietal bones of Wistar rats were filled with either bioglass or a biologic collagen scaffold seeded both with adipose-derived mesenchymal stem cells. The present study aims to present the applications of MRI in the assessment of the bone regeneration process in these previously created defects, at specific time intervals. MRI techniques are based on the differences between the spin-latice T1 and spin-spin T2 relaxation times of examined specimens or areas, compared to normal tissues. We measured the relaxation times specific to calvarial specimens with a Brukner Minispec. The results showed that the most favorable results were observed when a collagen scaffold seeded with stem cells was used. MRI enabled the detection of hard and even soft tissue changes, these findings suggesting that MRI could be an effective imaging modality for assessing changes in bone morphology and pathobiology. Furthermore, it can be used as an alternative to Computed Tomography in examining the role of various biomaterials used in bone healing, especially when ionizing radiation is contraindicated.
In this study, the effect of polymers on the mechanical properties of ketoprofen extended drug release systems were studied. Many polymers are added in formulation of compressed tablets in order to improve the physicochemical characteristics of the drug release system. The samples were made in the form of cylindrical tablet about 9 mm in diameter, containing different mixtures of drug substances and excipients acording to seven formulations. Cylindrical tablets containing mixtures of ketoprofen and various types of polymers are made by direct compression method. Among the binders used were a series of different polymers like Kollidon va 64, hydroxypropyl methyl cellulose and sodium carboxyl methyl cellulose. Mechanical parameters such as hardness, mechanical strenght, friability and roughness were studied in order to determine how they are influenced by polymeric binders.
Drilling of polymeric materials can be challenging when holes are produced in large scale due to the necessity of controlling the holes quality. This paper presents the effect of machining parameters on the hole quality, in terms of surface roughness and circularity error, in drilling of high density polyethylene, polyamide and polyacetale. The analysis of variance was performed in order to assess the significance of cutting parameter on the hole quality parameters. The experimental results indicate that different cutting conditions are to be employed in order to achieve the optimum surface roughness and circularity.
The ionic conductivity, ionic viscosity as intrinsic properties of PMMA - TiO2 nanocomposites were investigated. The PMMA doped with 0.4% TiO2 nanoparticles has been used for 3D printed dentures manufacturing. A structural characterization using micro-computer tomography method was performed on 3D printed dentures, which have been permanently used for 12 months. The obtained results revealed good morphological stability of the materials in vivo, in the oral environment. The reinforced polymer matrix with nanotitania particles showed a dielectric constant and conductivity dependent on frequency, exhibiting improved characteristics when compared to the pure polymer matrix.
This paper presents an experimental study on the potential use of new type of composite as insulation material. The composite material (AACW-UPR) was synthesised through mixture between the Autoclaved Aerated Concrete Waste (AACW) as filler and Unsaturated Polyester Resin (UPR) as matrix. Several samples of the composite material with different UPR concentrations (50 and 70 vol.%) and different AACW particle size (0.2-1 mm, 1.5-2.5 mm, 3-6 mm) were prepared. The thermal behaviour and the water absorption capacity of the AACW-UPR composite materials were studied. Also, the influence of water absorption capacity on thermal resistance and thermal conductivity was studied. During the investigations we noticed the following: good chemical compatibility between the AACW particles and the UPR matrix; a decrease in thermal conductivity for samples with 50 vol.% UPR and inserted particles size between 3-6 mm and an increase in water absorption capacity with the increase in the filler content in the matrix. The increasing water absorption capacity determined a decrease in thermal resistance and a reduction of the composite features as insulating material.
This paper presents and discusses research conducted with the purpose of developing the use of solar energy in the heat treatment of steels. For this, a vertical axis solar furnace called at Plataforma Solar de Almeria was adapted such as to allow control of the heating and cooling processes of samples made from 1.1730 steel. Thus temperature variation in pre-set points of the heated samples could be monitored in correlation with the working parameters: the level of solar radiation and implicitly the energy used the conditions of sample exposed to solar radiation, and the various protections and cooling mediums.The recorded data allowed establishing the types of treatments applied for certain working conditions. The distribution of hardness, as the representative feature resulting from heat treatment, was analysed on all sides of the treated samples. In correlation with the time-temperature-transformation diagram of 1.1730 steel, the measured values confirmed the possibility of using solar energy in all types of heat treatment applied to this steel. In parallel the efficiency of using solar energy was analysed in comparison to the energy obtained by burning methane gas for the heat treatment for the same set of samples. The analysis considered energy consumption, productivity and the impact on the environment. Thanks to various data obtained through developed experiences, which cover a wide range of thermic treatments applied steels 1.1730 model, we can certainly state that this can be a solid base in using solar energy in applications of thermic treatment at a high industrial level.
The interest in aesthetics of dental materials is becoming greater with time and dental ceramics have proven excellent aesthetic properties. The study investigated how does the oral environment and the different surface finishing affect the optical properties and roughness of two types of ceramic, obtained using the heat- pressed method. Results showed that immersion has some influence on the optical and roughness of the two types of ceramics, but the major influence is made by the surface finishing and the type of ceramic. Lithium disilicate ceramic proved to have better optical properties compared to feldspathic ceramic. Roughness values showed that the parameters(Ra and Rz) were influenced by the surface finishing for both type of ceramics.