SEARCH · Search PubMed

Results for “ACRYLATES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 595 records · Page 33Linked to original sources

PubMed1979

[Long-term results of plastic skull repairs with acrylic resins].

In the period from the beginning of 1956 until June 1978, we closed 312 skull gaps with acrylic resin. We used Palacos G (group I) 205 times and Refobacin Palacos R (group II) 107 times. Owing to the antibiotic action of Palacos, the infection rate, which was 6.8 per cent in the first group, could be lowered to 1.07 per cent even with a larger range of indications. The cosmetic results were very satisfactory. Owing to only slight changes in consistency and elasticity, a good protection of the brain was ensured. With the exception of one patient who temporarily showed psychic alterations, the acrylic resin was not felt as a foreign body. Disagreeable sensations, especially in case of the action of heat and cold such as are occasionally mentioned by wearers of metal plates, did not occur in our patients. Formation of neoplasms caused by polymethyl methacrylate has been found in none of the patients during the observation period of 20 years. The plastic repair with acrylic resin can be carried out quickly and in a simple manner. It may be used in all regions of the cranium. Even larger defects can be closed in this way.

Acrylic Resins↗

PubMed1984

alpha, beta-Diacryloxypropionic acid, a sensitizing impurity in commercial acrylic acid.

In samples of commercial acrylic acid a strongly contact sensitizing constituent was discovered by application of Freund's Complete Adjuvant Test in guinea pigs. The skin reactions were due to the presence of varying quantities of alpha,beta- diacryloxypropionic acid (DAPA), which was identified after methylation. The commercial product is an example of a composition that defies gas-chromatographic quality-control: Under the circumstances of this analysis the secondary product that is formed during the synthesis of acrylic acid is so unstable that it does not pass polar liquid phases. Distilled acrylic acid does not contain the sensitizing acid.

Acrylates↗

PubMed1993

A new method of attaching cast gold occlusal surfaces to acrylic resin denture teeth.

Historically, cast gold occlusal surfaces for complete or removable partial dentures have been fabricated with retentive loops or beads and luted to prepared denture teeth with acrylic resin or attached to tooth-colored, heat-processed acrylic resin. At present, alternatives to mechanical retention for attaching resin to metal include chemical bonding of the resin after placement of intermediate ceramic or tin layers and the use of chemically adhesive resin cements. Compared to mechanical retention, the chemical bonding of resin to metal requires less gold and allows more room for properly contoured and esthetic resin. Additionally, this chemical bond limits microleakage at the resin-metal interface. In the following technique, cast gold occlusal surfaces are fitted to onlay preparations of acrylic resin denture teeth set in a processed denture base. The castings are air-abraded, tin plated, and luted to the denture teeth with Panavia dental adhesive. This method is quick, easy, and economical.

Acrylic Resins↗

PubMed1994

The tensile and shear bond strength of a conventional and a 4-meta self-cure acrylic resin to various surface finishes of CoCr alloy.

This study was designed to compare the tensile and shear bond strengths of two self-cure acrylic resins to cobalt-chromium alloy (CoCr) samples, prepared with six surface finishes. The strongest mean tensile bond strength was recorded between the 4-Meta acrylic resin and Silicoated cobalt-chromium alloy. The strongest mean shear bond strengths showed little variation between the 4-Meta acrylic resin and Silicoated, sandblasted and sandblasted/tinplated cobalt-chromium. This laboratory based study may have important implications for the future design of CoCr dentures.

Acrylic Resins↗

PubMedDate not supplied

The role of denture cleansers on the whitening of acrylic resins.

Dentists and denture wearers have reported that the regular use of a denture cleanser causes whitening of dentures. The whitening effect of denture cleansers on acrylic resin dentures was investigated using four different types of agents on six different types of acrylic resin discs. The color values of the samples were measured using a reflectometer. The greatest whitening effect was seen on autopolymerizing acrylic resins for one of the denture cleansers with all the resins tested.

Acrylic Resins↗

PubMed1997

Reinforcement of acrylic resins for provisional fixed restorations. Part I: Mechanical properties.

Acrylic resins are commonly used in many dental applications; especially in the fabrication of provisional fixed partial dentures. Among noticed technical drawbacks associated with this material are unsatisfactory mechanical properties. Moreover, if acrylic resins are exposed to moist environment, water sorption results in further mechanical deterioration. In order to improve the mechanical properties, aluminum, magnesium, and zirconium oxide powders and pulverized E-glass particles were separately admixed with pre-polymerized acrylic resin beads prior to mixing with monomer liquid. Particle loading ratios were 1, 2 and 3 vol.% with respect to pre-polymerized beads. Poly(methyl methacrylate), poly(ethyl methacrylate) and poly(isobutyl methacrylate) were used as resin matrices. Furthermore, a metal primer agent was employed in order to form a strong interphase between admixed particles and polymer matrix phase. Samples were subjected to three-point transverse bending tests at a crosshead speed of 10 mm/min. It was concluded that (1) addition of particles generally increases the water sorbed by the composite resins systems, (2) however, two vol.% admixtures in a PMMA resin matrix showed significant improvements in the mechanical properties (p < 0.05), (3) among the oxide particles, zirconia exhibited the greatest improvements in modulus of elasticity, transverse strength, toughness and hardness, and (4) mechanical properties (transverse strength, 0.2% offset yield strength and modulus of elasticity) were linearly correlated to hardness numbers.

Acrylic Resins↗

PubMed1997

The effect of surface treated UHMWPE beads on some properties of acrylic resin denture base material.

UHMWPE in the form of experimental surface treated beads was added to acrylic resin denture base material in various percentages to form a composite material. The influence on doughing and manipulation times, and transverse and impact strength was examined. The results indicated that the manipulation times, were not significantly affected as the percentage of UHMWPE beads in the acrylic resin powder increased. Increasing the percentage of incorporated UHMWPE beads resulted in an inconsistent decrease in the modulus of rupture and no effect on the impact fracture resistance. It was concluded that the use of treated UHMWPE beads is of no significant benefit to the properties of acrylic resin.

Acrylic Resins↗

PubMed1998

Light-curing acrylic resin as an orthodontic baseplate material.

Heat-curing autopolymerizing (self-cure or cold-cure), thermoplastic, and light-curing acrylic resin are the most commonly used orthodontic baseplate materials. While cured acrylic resins present few problems to the patient, in the laboratory acrylic resin has to be sprayed, mixed, or packed in a fume-extraction unit because of the harmful fumes emitted by the raw inflammable chemicals. Light-curing material, on the other hand, is virtually nonflammable and has virtually no aroma. A light-cure technique for the construction of orthodontic baseplates is described. While buildup of the baseplate is slightly slower than for self-cured material, the shorter time involved in trimming and polishing means that overall construction is faster. It is easier to obtain a uniform thickness with light-cured material, and it provides superior fit. These results, however, are subject to more extensive clinical trials. The only apparent disadvantage is the fine powder produced during trimming. Even with a bench equipped with an extraction unit, it is advisable to use a face mask to prevent the inhalation of dust.

Acrylic Resins↗

PubMed1998

An acrylic ampoule represents a denture surface in a microcalorimetric biofilm problem.

An acrylic microcalorimetric ampoule with inserts represented a denture surface in a Streptococcus mutants biofilm study. The biofilm of micro-organisms did not contain as many micro-organisms as those previously studied in planktonic suspension. A more sensitive microcalorimeter (Thermometric's thermal activity monitor) was required to detect the metabolism of S. mutants adhered to an engineered acrylic flow-through ampoule. Biofilm heat outputs were obtained in the acrylic ampoule following standardized procedures with cryopreserved aliquots of a homogeneous suspension of S. mutants.

Acrylic Resins↗

PubMed1996

Experimental study of the antithrombogenic behavior of Dacron vascular grafts coated with hydrophilic acrylic copolymers bearing salicylic acid residues.

The objective of the present work was study of the behavior of active coatings of hydrophilic acrylic polymers bearing salicylic acid residues linked covalently to the macromolecular chains, after their application to woven and knitted Dacron vascular grafts. In vitro tests were carried out under dynamic flow conditions using equipment especially designed to reproduce physiologic conditions, to determine the retention of the coating using a saline solution. Ex vivo tests were carried out in an extracorporeal circuit using the dog as an animal model. The study of the deposition of platelets was followed by labeling of autologous platelets with 111In-oxine, as well as by analysis of the surfaces of the prostheses by scanning electron microscopy. An application of thin coatings of hydrophilic acrylic copolymers improves the antithrombogenicity of the vascular grafts with respect to the uncoated prosthesis. The presence of relatively small amounts of units bearing salicylic acid residues in the copolymer chains (5-20 wt %) gives good results when they are applied to woven and knitten Dacron meshes which have been quantified by analysis of the percentage of radiotracer on the surface of the vascular grafts tested in ex vivo experiments. The salicylic acid residues are released slowly to the medium by hydrolysis of the reversible covalent bonds of this compound to the acrylic macromolecular chains, which provides an additional antiaggregating effect for platelets. The polymeric coating forms a thin active film which improves the antithrombogenic properties of the surface of woven or knitted Dacron vascular grafts in ex vivo experiments.

Animals↗

PubMed1992

Polyhydroxy and polyethyleneglycol (meth)acrylate polymers: physical properties and general studies for their use as electrophoresis matrices.

A new series of materials have been tested for their suitability as electrophoresis matrices. The mechanical and optical properties of gels composed of polyethyleneglycol (meth)acrylate esters or polyhydroxy (meth)acrylate esters in water and in various concentrations of organic solvents are described. Several crosslinkers including polyethyleneglycol and polyhydroxy di(meth)acrylates, piperazine diacrylate, and bisacrylamide were used in these studies. Electrophoretic migration and separation of a series of protein standards through polyethyleneglycol methacrylate (PEGM) 200, PEGM 400, and glyceryl methacrylate is demonstrated. Further, copolymerization of all of the monomers with acrylamide was performed and the distribution of monomer incorporation into the polymer network calculated. All monomers and copolymers that were examined by IR spectroscopy showed greater than 99% polymerization. These results justify their further study for biomolecule separations.

Cross-Linking Reagents↗

PubMedDate not supplied

Acrylic frontal cranioplasty.

The correction of contour defects of the frontal bone has been accomplished with a variety of autogenous and alloplastic materials. We report our experience in reconstructing 11 cases of congenital, traumatic, and postsurgical frontal defects with acrylic. The acrylic was cured intraoperatively within the defect in some patients, or prefabricated into a prosthesis and wired into position in others. The operative techniques for both methods of repair are detailed. The reconstruction was successful in all cases and there were no complications. The acrylic implant has been found to be well tolerated after 2-10 yr follow-up. The value of the construction of a facial moulage is stressed, especially when restoration of the orbital rim is required.

Adult↗

PubMed2003

Biocompatibility and other properties of acrylic bone cements prepared with antiseptic activators.

Acrylic bone cements prepared with activators of reduced toxicity have been formulated with the aim of improving the biocompatibility of the final material. The activators used were N,N-dimethylaminobenzyl alcohol (DMOH) and 4,4'-dimethylamino benzydrol (BZN). The toxicity, cytotoxicity, and antiseptic action of these activators were first studied. DMOH and BZN presented LD50 values 3-4 times higher than DMT, were less cytotoxic against polymorphonuclear leucocytes, and possessed an antimicrobial character, with a high activity against the most representative microorganisms involved in postoperative infections. The properties of the acrylic bone cements formulated with DMOH and BZN were evaluated to determine the influence of these activators on the curing process and the physicochemical characteristics of the cements. A decrease of the peak temperature was observed for the curing with DMOH or BZN with respect to that of one commercially available formulation (CMW 3). However, residual monomer content and mechanical properties in tension and compression were comparable to those of CMW 3. The biocompatibility of acrylic bone cements containing DMOH or BZN was studied and compared with CMW 3. To that end, intramuscular and intraosseous implantation procedures were carried out and the results were obtained from the histological analysis of the surrounding tissues at different periods of time. Implantation of rods of cement into the dorsal muscle of rats showed the presence of a membrane of connective tissue, which increased in collagen fibers with time of implantation, for all formulations. The intraosseous implantation of the cements in the dough state in the femur of rabbits, revealed a higher and early osseous neoformation, with the presence of osteoid material surrounding the rest of the cured material, for the cement prepared with the activator BZN in comparison with that obtained following the implantation of the cement cured with DMOH or DMT (CMW 3).

Alcohols↗

PubMed2003

Fatigue testing and performance of acrylic bone-cement materials: state-of-the-art review.

Over the past three decades or so, a very large volume of literature has been generated on the impact of an assortment of variables on the fatigue lifetimes of a large number of acrylic bone-cement formulations. In the present article, this literature is examined critically to reveal areas of agreement, areas of disagreement, as well as a welter of underexplored and unexplored topics. For example, there is unanimity of support for the notion that an increase in the molecular weight of the powder constituents or the fully cured cement leads to an increase in the cement's fatigue life, whereas there is disagreement as to whether vacuum mixing the cement constituents leads to an increase in the fatigue life of the fully cured cement (relative to the hand-mixed counterpart). Among the underexplored topics is systematic study of the effect of test frequency on the fatigue results, whereas determination of the optimal concentration of the antibiotic in an antibiotic-loaded cement is an example of the unexplored topics. It is pointed out that resolving the controversies, addressing the underexplored topics, and filling the lacunae will allow comprehensive evaluations of acrylic bone-cement materials to be made. This enhanced body of knowledge will prove invaluable in the continued use of acrylic bone cement as the anchoring agent in cemented arthroplasties.

Animals↗

PubMed2006

Graft copolymers of methyl methacrylate and poly([R]-3-hydroxybutyrate) macromonomers as candidates for inclusion in acrylic bone cement formulations: Compression testing.

Graft copolymers of methyl methacrylate and biodegradable, biocompatible bacterial poly([R]-3-hydroxybutyrate) (PHB) blocks were synthesized and evaluated as possible constituents in acrylic bone cements for use in orthopaedic applications. The copolymers were produced by conventional free radical copolymerization and incorporated in one commercially available acrylic bone cement brand, Antibiotic Simplex (AKZ). Cements with formulations containing 6.7 and 13.5 wt % of PMMA-graft-PHB were prepared. The morphology of the graft copolymer particles was suggested to influence the ability of the modified cement to be processed. Formulations containing more than about 20 wt % of the graft copolymer resulted in cement doughs that, both after first preparation and several hours later, were either sandy or soft spongy in texture and, thus, would be unacceptable for use in orthopaedic applications. The morphologies of the powders and the volumetric porosity (p) and ultimate compressive strength (UCS) of the cured cements were determined. Micro computed tomography showed that the cements presented average porosities of 13.5-16.9%. It was found that, while the powder particle shape and size for the experimental cements were markedly different from those of AKZ, there was no significant difference in either p or UCS for these cements. The latter was determined to be about 85 MPa for the modified cements and 84 MPa for Antibiotic Simplex. Furthermore, the UCS of all the cements exceeded the minimum level for acrylic bone cements, as stipulated by ASTM F-451.

Biocompatible Materials↗

PubMed2004

Separation techniques for the analysis of artists' acrylic emulsion paints.

Emulsion paints are complex chemical systems. The main problems in their characterization are related to the similarities in polymer composition and to the presence of many different types of additives. Thus high resolution separations, sensitivity, and response specificity are required to identify simultaneously the polymer matrix and the minor components. Especially surfactants and pigments are thought to affect significantly the properties of the paint layers during ageing and their identification is the first step in evaluating the behaviour of these products in working conditions. Representative samples of acrylic emulsion paints for artists have been investigated by pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) and size exclusion chromatography-Fourier transform infrared spectroscopy (SEC-FTIR), and the results have been compared. All the analysed samples were bound in ethyl acrylate-methyl methacrylate, poly(EA-co-MMA), or n-butyl acrylate-methyl methacrylate, poly(nBA-co-MMA), copolymers. Two types of nonionic surfactants, ethoxylated fatty alcohols and alkylaryl polyethoxylates, commonly used as emulsifiers and dispersive agents have been identified, together with a number of organic pigments.

Journal Article↗

PubMed1998

Size Dependence of Polymer Composition in the Surface Layer of Poly(acrylamide-co-acrylic acid) Hydrogel Microspheres

Poly(acrylamide-co-acrylic acid) hydrogel microspheres of four different average sizes were prepared using a membrane emulsification technique. These four kinds of microspheres had average diameters of 1.35, 2.33, 3.09, and 7.43 &mgr;m in distilled water and were all fairly monodisperse. Their surface properties were studied by measuring the electrophoretic mobility of the microspheres. The mobility values were negative at pH 7.4 with the ionic strengths between 0.005 and 0.154 at 25°C. More negative mobility values were obtained with smaller microspheres than the larger ones. By analyzing the data with an electrokinetic theory for "soft" surfaces, it was found that smaller microspheres have higher surface charge density than the larger ones, although all kinds of microspheres were prepared from monomer solutions with the same monomer composition. The observed size dependence of the electrophoretic mobility suggests that copolymerization of acrylamide monomers and acrylic acid monomers does not proceed homogeneously within a microsphere. That is, charged acrylic acid monomers have a tendency to be localized in the microsphere core region, whereby the surface region of microspheres becomes poor in charges, reducing the mobility of larger microspheres. This is not the case for smaller microspheres, so that their mobility becomes more negative. Copyright 1998 Academic Press. Copyright 1998Academic Press

Journal Article↗

PubMed2007

Methotrexate-added acrylic cement: biological and physical properties.

BACKGROUND: Previous reports have demonstrated the suitability of adding different chemotherapeutic drugs to acrylic cement for the treatment of bone metastases. The best results so far have been obtained with methotrexate (MTX) for which diffusion from the implanted cement has been demonstrated both in vitro and in vivo. In this study the suitability of adding MTX to acrylic cement as local adjuvant chemotherapy was investigated. METHODS: Using an in vitro model of human breast cancer cells we demonstrated that the drug is eluted in an active form able to exert a cytotoxic effect over a long period of time. The use of different concentrations of drug on the kinetic of elution and on the mechanical properties of cement was also evaluated. RESULTS: The results obtained suggest that the release of MTX is higher at the beginning and progressively decreases over time being affected by the concentration of drug used. Our results also demonstrated that the addition and the subsequent elution of MTX does not alter the compressive properties of the cement. CONCLUSION: These findings confirm the suitability of MTX-supplemented cement and support its use as an effective aid for the management of bone metastases requiring surgical curettage and acrylic cement implantation for structural support.

Antineoplastic Agents↗