Search PubMed⌕ Search

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.

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

At least 271 records · Page 15Linked to original sources
PubMed2006

The effect of two fibre impregnation methods on the cytotoxicity of a glass and carbon fibre-reinforced acrylic resin denture base material on oral epithelial cells and fibroblasts.

Acrylic resin dentures may have cytotoxic effects on oral soft tissues. However, there is sparse data about the cytotoxic effect of fibre-reinforced acrylic resin denture base materials. The purpose of this in vitro study was to determine the effect of two fibre impregnation methods on the cytotoxicity of a glass and carbon fibre-reinforced heat-polymerized acrylic resin denture base material on oral epithelial cells and fibroblasts. One hundred acrylic resin discs were assigned to five experimental groups (n = 20). One of the groups did not include any fibre. Two groups consisted of silane and monomer treated glass fibres (Vetrolex) impregnated into acrylic resin (QC-20) discs. The other two groups consisted of silane and monomer treated carbon fibres (Type Tenox J, HTA). Untreated cell culture was used as positive control. The human oral epithelial cell line and buccal fibroblast cultures were exposed to test specimens. The cytotoxicity of the test materials was determined by succinic dehydrogenase activity (MTT method) after 24 and 72 h exposures. Data were analysed with a statistical software program (SPSSFW, 9.0). A one-way analysis of variance (anova) test and Bonferroni test were used for the comparisons between the groups. All statistical tests were performed at the 0.95 confidence level (P < 0.05). After 24 and 72 h incubation, cell viability percentages of all experimental groups showed significant decrease according to the positive control cell culture. Fibroblastic cell viability percentages of silane and monomer treated fibre-reinforced groups were lower than the unreinforced group. Cell viability of monomer-treated groups displayed the lowest percentages. Elapsed incubation time decreased epithelial cell viability in silane-treated groups. Fibroblastic cell viability was not influenced by elapsed time except the unreinforced group.

Acrylic Resins↗
PubMed2004

Formable acrylic treatment for ingrowing nail with gutter splint and sculptured nail.

BACKGROUND: The treatment of choice for an ingrowing nail has been surgical rather than nonsurgical. Yet, surgical treatments are far from successful, cause pain and patient apprehension, and leave disfigurement. Further, there is misunderstanding about the disease pathophysiology. OBJECTIVE: To demonstrate the benefits of a noninvasive method of treatment for an ingrowing nail using gutter splint and formable acrylics and to present a current understanding of the disease pathophysiology. METHODS: From a total of 541 cases of ingrowing nails treated, full follow-up data were obtained between January 1979 and March 2002. Formable acrylic treatments were carried out in 106 cases treated with acrylic-affixed gutter splint, 17 cases with sculptured nails, and 28 cases in which the two treatments were combined. These were then compared with 233 cases treated with adhesive tape-attached gutter splint and the remainder with other conservative modalities. RESULTS: Acrylic treatment with gutter splint and sculptured nail was found to be vastly superior to the other methods described, especially in the ability to firmly affix the gutter splint and sculptured nail for the extended period required for treatment. The treatment leads to a complete remission with almost instant alleviation of pain, with no disfigurement, while allowing for the resumption of daily activities. CONCLUSION: Conservative methods utilizing formable acrylics are highly beneficial in the treatment of an ingrowing nail and should be viewed as the first treatment option.

Acrylic Resins↗
PubMed1975

Cross-sensitization patterns in acrylate allergies.

Five subjects developed allergic contact dermatitis to one or more acrylate components used in a commercial adhesive tape. Patch testing to acrylic monomers was performed to examine their cross-reaction patterns. Two subjects with broad cross-reactions to acrylates did not react to methyl methacrylate or the alkyl methacrylate that corresponded to the acrylate which induced the sensitization. Methyl methacrylate may not be adequate as a screen for many acrylates used commercially.

Acrylates↗
PubMed1997

Purification and preliminary characterization of (E)-3-(2,4-dioxo-6-methyl-5-pyrimidinyl)acrylic acid synthase, an enzyme involved in biosynthesis of the antitumor agent sparsomycin.

Sparsomycin is an antitumor antibiotic produced by Streptomyces sparsogenes. Biosynthetic experiments have previously demonstrated that one component of sparsomycin is derived from L-tryptophan via the intermediacy of (E)-3-(4-oxo-6-methyl-5-pyrimidinyl)acrylic acid and (E)-3-(2,4-dioxo-6-methyl-5-pyrimidinyl)acrylic acid. An enzyme which catalyzes the conversion of (E)-3-(4-oxo-6-methyl-5-pyrimidinyl)acrylic acid to (E)-3-(2,4-dioxo-6-methyl-5-pyrimidinyl)acrylic acid has been purified 740-fold to homogeneity from S. sparsogenes. The molecular mass of the native and denatured enzyme was 87 kDa, indicating that the native enzyme is monomeric. The enzyme required NAD+ for activity but lacked rigid substrate specificity, since analogs of both NAD+ and 3-(4-oxo-6-methyl-5-pyrimidinyl)acrylic acid could serve as substrates. The enzyme was very weakly inhibited by mycophenolic acid. Monovalent cations were required for activity, with potassium ions being the most effective. The enzyme exhibited sensitivity toward diethylpyrocarbonate and some thiol-directed reagents, and it was irreversibly inhibited by 6-chloropurine. The properties of the enzyme suggest it is mechanistically related to inosine-5'-monophosphate dehydrogenase.

Acrylates↗
PubMedDate not supplied

Occupational asthma due to acrylates in a graphic arts worker.

BACKGROUND: Acrylates are used in a wide variety of products such as solvents, adhesives, paints, printing ink, soft contact lenses, porcelain nails, and methacrylates (used by dentists and orthopedists). Currently there are various types of acrylic compounds: acrylates, cyanoacrylates (such as tissue adhesives and home glues), and methacrylates (prostheses and dental and orthopedic fillings). The sensitization mechanism is unknown, but the allergy is believed to be due to a non-IgE mediated phenomenon, since a late asthmatic response occurs. Various cases of acrylate-induced asthma have been reported, especially in dentists and persons using glues or paints containing this substance. MATERIAL AND METHODS: We present the case of a 52-year-old man who had been working in graphic arts for the previous 7 years. For the previous 2 years he had experienced persistent cough with a sensation of drowning, dyspnea that increased with moderate exertion, and nasal obstruction despite continuous treatment. The symptoms first appeared after an episode of acute respiratory difficulty associated with weight loss, pulmonary infiltrates, and eosinophilia. Peak expiratory flow (PEF) was measured during work and sick leave, and specific bronchial challenge with acrylates was performed in a bronchial chamber. RESULTS: The PEF improved on weekends and sick leave. The challenge test provoked a late asthmatic response and the non-specific bronchial hyperreactivity increased after the test. As well in the sputum samples there was a increase of eosinophil amount.

Acrylates↗
PubMedDate not supplied

Exposure to subtherapeutic concentrations of polyene antifungals suppresses the adherence of Candida species to denture acrylic.

BACKGROUND: The adherence of Candida species to denture acrylic is the initial event leading to Candida-associated denture stomatitis, with Candida albicans being the main aetiological agent. However, the increased incidence of immunocompromised patients in the community has resulted in the emergence of a number of non-albicans Candida species as causative agents of this disease, which is commonly managed by topically delivered polyene antifungals. Hence, we investigated the effect of the exposure of denture acrylic surfaces to nystatin and amphotericin B on the subsequent adhesion of six different Candida species. METHODS: Acrylic strips were exposed to subtherapeutic concentrations of the two polyenes for 30 min, and the adhesion of 4 isolates each of C. albicans, Candida glabrata, Candida guilliermondii, Candida krusei, Candida parapsilosis and Candida tropicalis was assessed using a previously described in vitro method with slight modifications. RESULTS: Overall, the results indicated a 35.9% (p < 0.01) and 63.1% (p < 0. 01) reduction, respectively, in yeast adhesion to denture acrylic following exposure to nystatin and amphotericin B, although this effect was not uniform for all the tested isolates. Thus, all C. glabrata, 3 C. guilliermondii and a single isolate each of C. krusei, C. parapsilosis and C. tropicalis were not significantly affected by nystatin exposure, and a single isolate each of C. glabrata and C. guilliermondii were not significantly affected by amphotericin B. CONCLUSIONS: The present data, the first on the effect of polyenes on a wide range of Candida species, indicate that the in vitro exposure of denture acrylic to subtherapeutic concentrations of nystatin and amphotericin B suppresses the adherence of pathogenic Candida species in general.

Acrylic Resins↗
PubMed2004

Effect of plasma treatment on adhesion of self-curing repair resin to acrylic denture base.

Plasma irradiation on surface of heat-cured acrylic resin prior to processing self-curing acrylic resin is likely to effectively increase the adhesive strength between these materials for short-term period. However, long-term reliability of adhesive strength between these materials has not been clarified yet. In the present study, these materials were stored in water for a long period (100 days), and the effect on their shear bond strength was investigated. Forty-four test specimens with flat bonding test surface were made with heat-cured acrylic resin. They were divided into four groups according to treatment procedures for bonding surface: plasma treatment, adhesive primer application, adhesive primer application after plasma treatment, and no treatment (for control). Self-curing acrylic resin was processed against all bonding surfaces. After storage in water for 100 days, shear bond strength values between heat-cured and self-cured acrylic resins were measured. Specimens in plasma treatment group exhibited higher shear bond strength value than those in control, although the difference was not significant.

Acrylic Resins↗
PubMed2006

The effect of different solutions on the bond strength of soft lining materials to acrylic resin.

In this study, we investigated the effect of different solutions--coffee, tea, Turkish coffee, artificial saliva, mouthwash, denture cleanser, and distilled water--on the bond strength of soft lining materials (one acrylic- and three silicone-based) to acrylic resin. Acrylic specimens (40x10x10 mm) were prepared for the bond strength test. The specimens were stored in different solutions and tested after 24 hours, seven days, and 30 days. Using analysis of variance, the bond strength of soft lining materials to acrylic resin was found to be related to the type of material, storage time, and storage solution. Visco-gel had the lowest bond strength to cured acrylic resin, where its strength ranged from 0.149 MPa to 0.784 MPa. The bond strength of Visco-gel was also found to increase with time. Molloplast-B and Ufi Gel P demonstrated better bond strength than Visco-gel and Mollosil.

Acrylic Resins↗
PubMed1993

Comparison of cotton and acrylic socks using a generic cushion sole design for runners.

A longitudinal single-blind study was conducted to test the friction blister prevention properties of synthetic acrylic socks in a generic construction. This study serves as a comparison with the authors' previous work comparing acrylic and cotton socks in a patented padded construction. Twenty-seven long-distance runners provided data regarding dampness, temperature, friction blister incidence, severity, and size. Two different socks were tested; each was identical in every aspect of construction except the fiber content. One test sock was composed of 100% synthetic acrylic fibers, and the other was composed of 100% natural cotton fibers. These results were unsuccessful at demonstrating any superiority of cotton or acrylic fibers when knitting produced a generic "cushion sole" sock. The superiority of acrylic fibers has thus far been demonstrated only when sock knitting provides adequate anatomical padding [corrected].

Acrylates↗
PubMedDate not supplied

An investigation of heat transfer to the implant-bone interface related to exothermic heat generation during setting of autopolymerizing acrylic resins applied directly to an implant abutment.

Excessive heat generation at the implant-bone interface may cause bone damage and compromise osseointegration. Autopolymerizing acrylic resins are commonly used intraorally to join impression copings and suprastructure components for soldering. The effect of heat generation at the implant surface related to the exothermic setting reaction of autopolymerizing acrylic resins applied to an attached abutment was examined in vitro. Two brands of autopolymerizing acrylic resin, Duralay and GC Pattern Resin, were compared. Acrylic resin was applied to a titanium alloy abutment connected to a titanium alloy cylindric implant in varying controlled volumes, with both bulk application and brush paint-on techniques. The implant was embedded in an acrylic resin mandible in a 37 degrees C water bath. Temperature changes were recorded via embedded thermocouples at the cervical and apical of the implant surface. Analysis of variance for repeated measures was used to compare treatment groups. A mean maximum increase in temperature of 4 to 5 degrees C was seen at the implant cervical for both materials, with a maximum temperature increase of 6 degrees C. No difference between Duralay and GC Pattern Resin was seen, except for bulk application to medium-sized copper bands at the implant cervical (P < .05). No difference between the bulk and brush techniques was seen for all options, except for GC, where bulk application to medium-sized copper bands produced higher temperatures than the brush technique (P < .05). Spray coolant reduced temperatures for bulk application of both Duralay and GC (P < .05).

Acrylic Resins↗
PubMed2002

Effect of commercial acrylic resins on dimensional accuracy of the maxillary denture base.

Denture base dimensional changes were found with commercial thermocured acrylic resins. Fifteen stone cast-wax base sets were packed for routine flasking. Clássico, Vipcril, and Meliodent Multicryl acrylic resins were prepared according to manufacturer instructions. After final acrylic resin pressing, the flasks were placed in strain clamps and submitted to polymerization cycles in heat-water following manufacturer instructions. The resin bases were fixed on casts with instant adhesive and the sets laterally sectioned in the corresponding regions to the distal of canines (A), mesial of first molars (B), and posterior palatal zone (C). The gap between the stone cast and resin base was verified with a measuring microscope at five reference positions for each type of cut. The data were submitted to ANOVA and Tukey's test and a significant statistical difference between the commercial acrylic resins was shown. The pattern of distortion verified in the posterior palatal region was confirmed in the C cut with significant statistical differences among the three acrylic resins. However, there were no significant statistical differences in A and B cuts.

Acrylic Resins↗
PubMedDate not supplied

Comparison of impact strength of acrylic resin reinforced with kevlar and polyethylene fibres.

The present study was done to evaluate the impact strengths of heat-activated acrylic resins reinforced with Kevlar fibres, polyethylene fibres and unreinforced heat activated acrylic resin. Each of three groups had 25 specimens. Brass rods of uniform length of 40 mm and diameter of 8 mm were used to prepare the moulds. A combination of long fibres (40 mm length) and short fibres (6 mm length) were used. The total amount of fibres incorporated was limited to 2% by weight of the resin matrix. Short and long fibres of equal weight were incorporated. The short fibres were mixed with polymer and monomer and packed into the mould, while, the long axis of the specimen, perpendicular to the applied force. The specimens were then processed. Impact strength testing was done on Hounsfield's impact testing machine. Kevlar fibre reinforced heat activated acrylic resin specimens recorded higher mean impact strength of 0.8464 Joules, while polyethylene fibres reinforced heat activated acrylic resin recorded mean impact strength of 0.7596 joules. The unreinforced heat activated acrylic resin recorded mean impact strength of 0.3440 Joules.

Acrylic Resins↗
PubMed2003

[Clinical evaluation of two temporary restoration materials: Composite and self-cured acrylic resin].

OBJECTIVE: The purpose of this study was to compare the clinical application and effect of two temporary restorations materials: composite and self-cured acrylic resin. METHODS: 153 composite temporary crowns (and bridges) placed in 44 patients and 144 self-cured acrylic resin temporary crowns (and bridges) placed in 49 patients were evaluated according to the California Dental Association's (CDA) criteria and questionnaire. RESULTS: It showed that composite temporary crowns (and bridges) had better surface smoothness, marginal integrity and anatomic form than self-cured acrylic resin temporary crowns (and bridges). In the 49 patients with self-cured acrylic resin temporary crowns (and bridges), 67% and 88% of them complained of food impaction and mouth odor, while only 2% and 30% in the 44 patients with composite temporary crowns (and bridges) had the same complaint. CONCLUSION: Between the two temporary restoration materials, composite is better than self-cured acrylic resin.

Acrylic Resins↗
PubMedDate not supplied

Accuracy of the acrylic resin pattern for the implant-retained prosthesis.

An in vitro study was conducted to determine the accuracy of fit of the acrylic resin pattern for the implant-supported prosthesis to the implant abutments. A master model containing five Nobelpharma titanium implants was fabricated using Ivocap acrylic resin. Using this model, five standardized acrylic resin patterns were fabricated from the three test dental acrylic resins. The fabricated patterns remained on the master model for 24 hours before removal and subsequent measurement. To compute the accuracy of each pattern, three special measuring points were firmly attached to each gold cylinder prior to pattern fabrication and the x, y, and z coordinates of these measuring points were determined. Measurements were made prior to pattern fabrication, with the cylinders on their respective abutments and after pattern fabrication, when the pattern had been removed from the master model. The results of this study showed that there was a significant difference in accuracy between the test acrylic resins and that none of these materials was completely accurate.

Acrylic Resins↗
PubMedDate not supplied

The effects of three-piece or single-piece acrylic intraocular lens implantation on posterior capsule opacification.

PURPOSE: To evaluate the development of posterior capsule opacification (PCO) in patients implanted with 5.5 mm optics, single-piece or three-piece acrylic intraocular lens (IOL) in cataract surgery prospectively. METHODS: This study was carried out on 267 eyes of 249 patients implanted with three-piece, 5.5 mm optics, acrylic IOL and 252 eyes of 244 patients implanted with single-piece, 5.5 mm optics, acrylic IOL by phacoemulsification technique between September 2001 and February 2003. A total of 519 eyes of 493 patients were prospectively evaluated for PCO development during the 25-month period. All the patients were analyzed periodically with anterior segment retroillumination photography. The data provided were analyzed with chi-square method. RESULTS: The results between the two groups for PCO development were not statistically significant. However, there was a prominent opacification of the posterior capsule where the optic and haptic junction of IOL was positioned in some patients implanted with single-piece IOL. During the follow-up period, no patients implanted with either three-piece or single-piece acrylic IOL required Nd:YAG laser capsulotomy. CONCLUSIONS: Biocompatibility and reduced rate of PCO development are among the leading features of new generation IOLs. The intracapsular implantation of 5.5 mm optics acrylic IOLs resulted in decreased incidence of PCO and therefore greater patient satisfaction. Further studies investigating the effects of IOL optics, haptic structure and length, capsulorrhexis size, and IOL material and design features on PCO development will clarify the subject.

Acrylic Resins↗
PubMed2006

An in vitro investigation of the effect of the addition of untreated and surface treated silica on the transverse and impact strength of poly(methyl methacrylate) acrylic resin.

Silica is a commonly used filler in dental materials and as a reinforcing agent in industry. The aim of this study was to further investigate the effect of the addition of untreated and a novel surface treated silica on the transverse bend and impact strength of acrylic resin denture base material. It was hypothesized that the silica/resin composite materials would have an improved flexural and impact strength than the conventional heat-cured acrylic resin. Three types of untreated and two of treated silica powder were used in this study. The range of percentages used were 1%, 0.5%, 0.2%, 0.1%. The treated particles were coated with hexamethyldisilazane or dimethyldichloridesilazane. Conventional heat cured acrylic resin was used as a control. The modulus of rupture for all groups of acrylic resin containing silica was significantly lower than for the control. The modulus of elasticity was not significantly greater than the control group. For the impact strength statistical analysis revealed a significant difference between the groups. There was a nonsignificant increase in the impact strength for specimens compared to the control. In conclusion the addition of silica to poly(methyl methacrylate) denture base materials did not produce a significant improvement in the transverse bend or impact strength compared to conventional heat-cured acrylic resin. The incorporation of untreated and surface treated silica cannot be recommended as a method of reinforcement.

Acrylic Resins↗
PubMed2006

The investigation of solubility values,water sorption and bond strength of auto-polymerising and heat-polymerising acrylic resin materials.

In this study the solubility, water sorption and the bond strength of auto-polymerising and heat-polymerising acrylic resins were investigated. Two auto-polymerising and five heat polymerising acrylic resin materials were used for this study. Thirty-five specimens were prepared (50 mm in diameter and 0.5 +/- 0.01 in thickness) for water sorption and solubility tests. In order to examine bond strength, specimens were prepared in 2.5 x 10 x 64 mm dimensions. These specimens were repaired with QC and major repair acrylic. Some specimens were kept in distilled water for 50 hours, and others for 30 days. The strength of the bond was measured by a Pull-Compress device. As a result of the variance analysis; water sorption, solubility and the bond strength between acrylic resins were identified as statistically significant (P < 0.001). The water sorption of the major acrylic resin specimens were lower than the other materials (P < 0.001).

Absorption↗