6 research outputs found
PrzeciweozynofilowedziałanieIL-12 w hodowanej tkance ludzkiego polipa nosa
Rationale: Tissue eosinophilia is an important pathophysiological issue in bronchial ashma and nasal polyps. Its magnitude is regulated by several mechanisms, including selective migration of eossinophils to peripheral
tissues and prolongation of survival. A key role in this processes is assigned to Th2 originating cytokines: IL-3, IL-5, GM-CSF. It has been previously demonstrated that IL-12 diminishes tissue eosinophilia in an animal model, and Hofstra showed that Il-12 together with IL-18 prevents allergen-induced increase bronchial hyperresponsiveness,
BAL eosinophilia and the development of allergen-specific Th2 cells. Methods: Nasal polyps were obtained during routine surgery and were cultured in fragments of approximately 30 mg for 2, 6, and 15 days in RPMI 1640 in the absence or presence of IL-12. Afterwards a dose-dependency was tested at day 2 of culture. Polyp tissue from cultures was than processed to slides, stained with Giemsa and cells were counted in light microscopy (400x). Results: Eosinophils represented 62,8 ± 21,3% of residing cells in nasal polyps at the day 0. IL-12 (1 μg/ml) caused a significant time-dependent decrease in the percentage of Eos after 2 and 6 days. The effect of IL-12 at day 2 was concentration-dependent: control, 28,2 ± 2,9; at 10 ng/ml, 13,9 ± 6,4 (n = 4, p < 0,05); at 100 ng/ml, 11,6 ± 2,1 (p < 0.01); at 1 μg/ml, 7,5 ± 1,5 (p < 0,005). Conclusion: IL-12 acts as potent topical antieosinophilic agent. Its action can be seen in a cultured polyp environment. It is visible already after two days and is concentration-dependent. Further study is needed to elucidate tissue mechanisms of this action
Resin Composite Materials for Chairside CAD/CAM Restorations: A Comparison of Selected Mechanical Properties
Objective. The aim was to evaluate the flexural strength, flexural modulus, microhardness, Weibull modulus, and characteristic strength of six resin composite blocks (Grandio Blocs-GR, Tetric CAD-TE, Brilliant Crios-CR, Katana Avencia-AV, Cerasmart-CS, and Shofu Block HC-HC). Methods. Flexural strength and flexural modulus were measured using a three-point bending test and microhardness using the Vickers method. Weibull analysis was also performed. Results. The materials showed flexural strength ranging from 120.38 (HC) to 186.02 MPa (GR), flexural modulus from 8.26 (HC) to 16.95 GPa (GR), and microhardness from 70.85 (AV) to 140.43 (GR). Weibull modulus and characteristic strength ranged from 16.35 (CS) to 34.98 (TE) and from 123.45 MPa (HC) to 190.3 MPa (GR), respectively. Conclusions. GR, TE, and CR presented significantly higher flexural strength, modulus, Weibull modulus, and characteristic strength than the others
Influence of Artificial Aging on Mechanical Properties of Six Resin Composite Blocks for CAD/CAM Application
(1) The interactions in the oral cavity between resin composite blocks for CAD/CAM application and saliva, biofilm, and chemicals and their influence on mechanical properties are still mostly unknown. The purpose of this study is to examine the impact of artificial aging on the flexural strength, flexural modulus, hardness, Weibull modulus, and probability of failure of six resin composite CAD/CAM materials. (2) The aging was conducted by storing the specimens in water at 37 °C for 3 months, then a 3-point bending test was applied and measured. The microhardness was measured with a Vickers microhardness tester. Weibull analysis (according to ISO) was also performed. The shape and scale parameters were calculated. (3) After aging, the flexural strength values ranged from 95.51 (SD 9.07) MPa for the aged Shofu Block HC (HC) to 160.28 (SD 10.37) MPa for non-aged Gandio blocks (GR), and the flexural modulus values ranged from 7.75 (SD 0.19) GPa for HC to 16.77 (SD 0.60) GPa for GR. The microhardness (HV01) ranged from 72.71 (SD 1.43) for the Katana Avencia Block (AV) to 140.50 (SD 5.51) for GR. After aging, the Weibull characteristic strength ranged from 99.47 MPa for HC to 169.25 MPA for Brilliant Crios (CR). (4) Water storage led to a decrease in flexural strength and characteristic strength and slightly affected the flexural modulus. Gandio Blocks, Tetric CAD, and Brilliant Crios presented higher flexural strength than others
Comparison of the Accuracy of 3D Images Obtained fromDifferent Types of Scanners: A Systematic Review
Introduction. The purpose of this systematic review was to compare the accuracy of the three-dimensional images among different scanners, scanning techniques, and substrates. Materials and methods. Electronic databases (PubMed and Elsevier) were searched until March 2020. The systematic search was performed to identify the most precise method of obtaining a 3D image of the dentition. Results. Thirteen articles out of 221, considering the accuracy of 3D images, were selected. The main factors that are considered to have an influence on the precision are substrate type in the oral cavity, experience of the scanner’s operator, direct vs. indirect scanning, and the reproducibility of the procedure. Conclusion. Substrate type does have an impact on the overall accuracy of intraoral scans where dentin has the most and enamel the least accurately recorded dental structure. Experience of the operator has an influence on the accuracy, where more experienced operators and smaller scan sizes are made for more accurate scans. A conventional impression technique in a full-arch image provided the lowest deviation. The reproducibility of direct scanning was comparable to indirect scanning although a slight difference was noticeable (0.02 mm)
The Influence of Various Preparation Parameters on the Histological Image of Bone Tissue during Implant Bed Preparation—An In Vitro Study
The purpose of this study was to present the level of bone tissue deformation after drilling under variable conditions in three different dental implant systems in a microscopic analysis. Straumann, Osstem, and S-Wide systems were used to drill boreholes in 27 porcine ribs at three different rotation speeds and under three different cooling conditions. The material was analyzed using a Nikon 80i microscope. The analysis concerned the morphological quality of the obtained boreholes. The statistical analysis revealed that satisfactory results in all drilling systems were obtained when the rotational speed did not exceed 800 revolutions per minute (rpm) regardless of the cooling temperature. However, increased rotational speed and cooling at 4 °C produced better results than without cooling in all the tested systems. Different implant systems have unique drill geometry and therefore generate differences in tissue damage under various conditions. In the experiment, a sufficient required structure was obtained in all systems, but the Straumann system yielded the best results under all the examined conditions