Silicone Dotaz Zobrazit nápovědu
This paper deals with composite structures for biomedical applications. For this purpose, an architectured tubular structure composed of Nickel Titanium (NiTi) Shape Memory Alloy (SMA) and silicone rubber was fabricated. One of the main interests of such structures is to ensure a good adhesion between its two constitutive materials. A previous study of the authors (Rey et al., 2014) has shown that the adhesion between NiTi and silicone rubber can be improved by an adhesion promoter or plasma treatment. However, adhesion promoters are often not biocompatible. Hence, plasma treatment is favored to be used in the present study. Three different gases were tested; air, argon and oxygen. The effects of these treatments on the maximum force required to pull-out a NiTi wire from the silicone rubber matrix were investigated by means of pull-out tests carried out with a self-developed device. Among the three gases, a higher maximum force was obtained for argon gas in the plasma treatment. A tube shaped architectured NiTi/silicone rubber structure was then produced using this treatment. The composite was tested by means of a bulge test. Results open a new way of investigations for architectured NiTi-silicone structures for biomechanical applications.
- Klíčová slova
- Adhesion, Architectured composite, Biomedical applications, Filled silicone rubber, Interface, NiTi,
- MeSH
- argon chemie MeSH
- kyslík chemie MeSH
- nikl krev chemie MeSH
- pevnost v tahu MeSH
- silikonové elastomery chemie MeSH
- slitiny chemie MeSH
- testování materiálů MeSH
- titan krev chemie MeSH
- vzduch MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- argon MeSH
- kyslík MeSH
- nikl MeSH
- silikonové elastomery MeSH
- slitiny MeSH
- titan MeSH
- titanium nickelide MeSH Prohlížeč
During the fabrication of a complete denture, functional impression is taken. Literature studies show that polydimethylsiloxane (condensation silicone) has not been reported by United States dental schools to perform border molding. Thus, the purpose of this article is to review the functional impression technique when border molding is performed with a laboratory condensation silicone putty.
- Klíčová slova
- Border moulding, Complete denture, Dental impression technique, Polydimethylsiloxanes, Silicone elastomers,
- MeSH
- celkové zubní protézy * MeSH
- lidé MeSH
- silikony * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- silikony * MeSH
Composite materials consisting of a silicone rubber matrix and particulate synthetic hydrogels were prepared and their mechanical properties were studied. The influence of the size, shape, aggregation of hydrogel particles, chemical reactions of polymer phases on tensile properties and tear strength of the composite materials were investigated. The relations between the properties, structure and chemical composition of polymer phases of the composite materials and their mechanical properties are discussed.
- MeSH
- biokompatibilní materiály * MeSH
- gely chemie MeSH
- methakryláty chemie MeSH
- pevnost v tahu MeSH
- polymery MeSH
- reagencia zkříženě vázaná MeSH
- silikonové elastomery * MeSH
- složené pryskyřice * MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- biokompatibilní materiály * MeSH
- gely MeSH
- hydroxyethyl methacrylate MeSH Prohlížeč
- methakryláty MeSH
- polymery MeSH
- reagencia zkříženě vázaná MeSH
- silikonové elastomery * MeSH
- složené pryskyřice * MeSH
A composite material was prepared consisting of silicone rubber matrix and particulate lightly cross-linked poly(2-hydroxyethyl methacrylate) (p(HEMA] hydrogel. The material resembling common silicone rubber is hydrophilic and swells in water like hydrogels. The effects of the implanted composite on tissues of the living organism were tested in rats by methods assessing local acute and chronic inflammatory reactions and calcification by means of radioactive indicators and by histological examination. Results of a 6 month implant study indicated no difference in reactions of the animal body on the silicone rubber-p(HEMA) composite and a non-toxic, non-irritant pure solid p(HEMA) control.
- MeSH
- biokompatibilní materiály * MeSH
- fibrin analýza MeSH
- inbrední kmeny potkanů MeSH
- kolagen analýza MeSH
- krysa rodu Rattus MeSH
- polyhydroxyethylmethakrylát * MeSH
- protézy a implantáty * MeSH
- radioisotopová scintigrafie MeSH
- radioizotopy india MeSH
- silikonové elastomery * MeSH
- složené pryskyřice * MeSH
- zánět diagnostické zobrazování patologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- biokompatibilní materiály * MeSH
- fibrin MeSH
- kolagen MeSH
- polyhydroxyethylmethakrylát * MeSH
- radioizotopy india MeSH
- silikonové elastomery * MeSH
- složené pryskyřice * MeSH
OBJECTIVES: A stent is a mesh tube inserted into a natural passage in the body to prevent disease induction. Self-expandable esophageal nitinol stents such as SX-ELLA Stent Esophageal HV (HV Stent Plus) can be indicated for palliation of malignant esophageal strictures, for the treatment of benign esophageal strictures that are refractory to standard therapy and for the treatment of esophago-respiratory fistulas. A silicone-stent coating is used for tumor in-growth prevention and esophago-respiratory fistula occlusion. The thickness of the stent and the overall integrity of the silicone coating of all wires indicate the overall mechanical properties of the esophageal stent and the resistance to external adverse events such as corrosion and mechanical and chemical resistance. METHODS: The polymer multicomponent epoxy resin - a mixture of Epon and Durcupan - was used as a method for robust sample stabilization. A cutting system using a thin water beam with a powder (Blue Line) was chosen as the best variant to obtain 6 samples for both-sided measurement (10 measuring sides). The optical microscopic reflective light method was used to examine wire crossing points in the sections. Fifty values were measured on either sample side for the internal, external and mesh thickness of the silicone stent layer. The wire crossing points were selected so that the silicone layer structure could be clearly seen, and the wires approached each other most closely. Only approximately 4 to 8 crossing points in each section could be measured when applying this approach. The resolution of the microscope and calibration (based on the camera used) was 0.677 μm/pixel. RESULTS: Additional data could be obtained on 8 planes. Two boundary samples were destroyed by the cutting process. Whole coating of the stent was around all mesh wires, especially in areas with higher mechanical stress (wire crossing). The minimum detectable and admissible value determined for all 3 measuring areas (internal, external, mesh) on the wire crossings was 6.77 μm, i.e., 10 pixels, based on the microscope resolution and manufacturer's methodology. The results were characterized by p < 0.001 for all 3 parameters. We tested opposite samples in each section to verify the section quality and data consistency. For the 4 areas, the data were significantly different, but the thickness differences were only on the order of units percent, so the measurements were not appreciably affected. We assume that the material cutting loss, making up 1-2 mm, contributed to the differences in the sections. CONCLUSION: We examined the overall integrity of the silicone coating of the esophageal stent. The method of HV stent anchoring in a polymeric bath followed by cutting with a waterjet and sample measurement under an optical microscope proved to be very simple and reliable. Sufficient thicknesses of the silicone layer on the wire cross sections were verified. The coated silicone layer thickness appeared to be significantly different along the stent from the proximal part to the distant part, presumably due to the manufacturing technology.
- Klíčová slova
- CNC technology, contactless, epoxy resin, memory materials, nitinol, optical method, self-expandable, silicone coating, stent,
- MeSH
- lidé MeSH
- obstrukce dýchacích cest * MeSH
- silikony * MeSH
- slitiny MeSH
- stenóza MeSH
- stenty MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- nitinol MeSH Prohlížeč
- silikony * MeSH
- slitiny MeSH
The use of silicone and latex drains is an integral part of surgical practice. Experience and the review of the world literature show that silicone drain is characterized by a much lower rate of fibrotic reaction of the tissue around the drain. The ability of a latex, or rubber, or popularly called rubber drain, to induce the formation of ligaments in its surroundings is advantageously used in situations where the targeted formation of scar tissue is desired. This feature is absent in silicone drains. However, nowadays the rule in most surgical departments is to use almost exclusively silicone drains, which is based on prevention of latex allergy. This article is devoted to the description of the different and mutually irreplaceable use of silicone and latex drains. Subsequently, he also discusses the question of whether the twilight of the use of latex drains in modern medicine is really progress, or rather retrogression.
Osseous reconstruction of the thumb following traumatic bone loss can be approached through a variety of techniques. The use of a silicone spacer with secondary bone grafting is a valid therapeutic option. In case of combined injuries, simultaneous immediate reconstruction of missing soft tissues over the spacer by well-vascularised skin cover is essential. Dorsoradial forearm flap has recently been described as distally based cutaneous pedicled flap on the dorsoradial artery, a constant branch of the radial artery. A case of a 52-year-old male patient with a combined injury of the thumb with bone loss of the proximal phalanx and with the loss of dorsal skin reconstructed primarily with bone silicon spacer and together with emergency dorsoradial forearm flap is reported together with a brief literature review.
- Klíčová slova
- Thumb, bone, dorsoradial, flap, forearm, graft., pedicled, reconstruction, silicone, spacer,
- MeSH
- kosti prstů ruky zranění chirurgie MeSH
- lidé středního věku MeSH
- lidé MeSH
- palec ruky zranění chirurgie MeSH
- protézy a implantáty * MeSH
- silikony MeSH
- volné tkáňové laloky * krevní zásobení MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
- Názvy látek
- silikony MeSH
The structure of silicone rubber-hydrogel composite materials was investigated by scanning electron microscopy (SEM) and light microscopy. The polymer phases in these materials composed of the polysiloxane matrix and very small particles of lightly cross-linked poly(2-hydroxyethylmethacrylate) or poly(2-hydroxyethylmethacrylate-co-methacrylic acid) were visualized using both methods. The distribution of polymer phases was studied by SEM of fracture surfaces of the materials. The results are discussed in relation to the transport properties of the materials.
In a 50-year-old man, penetrating keratoplasty was carried out to treat a diffuse silicone keratopathy that developed 2 years after a pars plana vitrectomy combined with an intravitreal silicone injection for a complicated retinal detachment in the only aphakic eye. At 2 weeks after the intravitreal silicone injection, specular microscopy revealed a mild pleomorphism in the corneal endothelium and an endothelial cell loss of 26%. After 5 months, a small silicone drop floated in the anterior chamber and the first signs of diffuse keratopathy were observed. At the same time, specular microscopy revealed severe damage to the endothelial cells and a cell loss of 69%. After the keratoplasty, scanning electron microscopy of the corneal button showed a filamentous structure of the posterior surface of the cornea, with fibroblast-like cells; the endothelial cells were absent.
- MeSH
- edém rohovky etiologie patologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- mikroskopie elektronová rastrovací MeSH
- nemoci rohovky etiologie patologie MeSH
- odchlípení sítnice chirurgie MeSH
- perforace sítnice chirurgie MeSH
- přední komora oční MeSH
- rohovkový endotel patologie ultrastruktura MeSH
- silikonové oleje škodlivé účinky MeSH
- transplantace rohovky škodlivé účinky MeSH
- vitrektomie MeSH
- zraková ostrost MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
- Názvy látek
- silikonové oleje MeSH
