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Sample records for acrylic resins part

  1. Impression techniques for multiple implants: a photoelastic analysis. Part II: comparison of four acrylic resins.

    PubMed

    Lopes-Júnior, Itamar; de Lima Lucas, Barbara; Gomide, Henner Alberto; Gomes, Vanderlei Luiz

    2013-10-01

    Four commercial brands of chemically activated acrylic resin were compared through photoelastic analysis. Photoelastic resin blocks were made with 2 implants placed parallel to each other and 2 square transfer copings splinted. Both transfers were splinted with chemically activated acrylic resin: Dencrilay, Duralay I, Duralay II, and GC. Data were analyzed by 2-way analysis of variance and Tukey test (P < .05). Statistically significant differences were found among the 3 brands of chemically activated acrylic resin. Dencrilay showed greater dimensional alteration. Duralay I and GC are recommended for the transfer of the position of the multi-implants.

  2. [Acrylic resin removable partial dentures].

    PubMed

    de Baat, C; Witter, D J; Creugers, N H J

    2011-01-01

    An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of removable partial dentures, the acrylic resin removable partial denture has 3 favourable aspects: the economic aspect, its aesthetic quality and the ease with which it can be extended and adjusted. Disadvantages are an increased risk of caries developing, gingivitis, periodontal disease, denture stomatitis, alveolar bone reduction, tooth migration, triggering of the gag reflex and damage to the acrylic resin base. Present-day indications are ofa temporary or palliative nature or are motivated by economic factors. Special varieties of the acrylic resin removable partial denture are the spoon denture, the flexible denture fabricated of non-rigid acrylic resin, and the two-piece sectional denture. Furthermore, acrylic resin removable partial dentures can be supplied with clasps or reinforced by fibers or metal wires.

  3. 21 CFR 173.5 - Acrylate-acrylamide resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... additive consists of one of the following: (1) Acrylamide-acrylic acid resin (hydrolyzed polyacrylamide) is... and acrylic acid, with the greater part of the polymer being composed of acrylamide units. (2)...

  4. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Acrylamide-acrylic acid resins. 176.110 Section... Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be...) Acrylamide-acrylic acid resins are produced by the polymerization of acrylamide with partial hydrolysis or...

  5. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid resin... acrylamide with partial hydrolysis, or by copolymerization of acrylamide and acrylic acid with the...

  6. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid resin... acrylamide with partial hydrolysis, or by copolymerization of acrylamide and acrylic acid with the...

  7. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid resin... acrylamide with partial hydrolysis, or by copolymerization of acrylamide and acrylic acid with the...

  8. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid resin... acrylamide with partial hydrolysis, or by copolymerization of acrylamide and acrylic acid with the...

  9. Bonding auto-polymerising acrylic resin to acrylic denture teeth.

    PubMed

    Nagle, Susan; Ray, Noel J; Burke, Francis M; Gorman, Catherine M

    2009-09-01

    This study investigated the effect of surface treatments on the shear bond strength of an auto-polymerising acrylic resin cured to acrylic denture teeth. The surface treatments included a combination of grit-blasting and/or wetting the surface with monomer. Samples were prepared and then stored in water prior to shear testing. The results indicated that the application of monomer to the surface prior to bonding did not influence the bond strength. Grit blasting was found to significantly increase the bond strength. PMID:19839190

  10. 21 CFR 173.5 - Acrylate-acrylamide resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylate-acrylamide resins. 173.5 Section 173.5... CONSUMPTION Polymer Substances and Polymer Adjuvants for Food Treatment § 173.5 Acrylate-acrylamide resins. Acrylate-acrylamide resins may be safely used in food under the following prescribed conditions: (a)...

  11. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylamide-acrylic acid resins. 176.110 Section 176... Substances for Use Only as Components of Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely used as components of articles intended for use in...

  12. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Acrylamide-acrylic acid resins. 176.110 Section... Substances for Use Only as Components of Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely used as components of articles intended for use in...

  13. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acrylamide-acrylic acid resins. 176.110 Section... Substances for Use Only as Components of Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely used as components of articles intended for use in...

  14. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Acrylamide-acrylic acid resins. 176.110 Section... Substances for Use Only as Components of Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely used as components of articles intended for use in...

  15. 40 CFR 721.10307 - Acrylate resin (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Acrylate resin (generic). 721.10307... Substances § 721.10307 Acrylate resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as acrylate resin (PMN P-01-343) is subject...

  16. 40 CFR 721.10307 - Acrylate resin (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Acrylate resin (generic). 721.10307... Substances § 721.10307 Acrylate resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as acrylate resin (PMN P-01-343) is subject...

  17. 21 CFR 173.5 - Acrylate-acrylamide resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acrylate-acrylamide resins. 173.5 Section 173.5... CONSUMPTION Polymer Substances and Polymer Adjuvants for Food Treatment § 173.5 Acrylate-acrylamide resins. Acrylate-acrylamide resins may be safely used in food under the following prescribed conditions: (a)...

  18. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573.120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid...

  19. 40 CFR 721.10307 - Acrylate resin (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Acrylate resin (generic). 721.10307 Section 721.10307 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10307 Acrylate resin...

  20. Acrylic Resin Cytotoxicity for Denture Base--Literature Review.

    PubMed

    Goiato, Marcelo C; Freitas, Emily; dos Santos, Daniela; de Medeiros, Rodrigo; Sonego, Mariana

    2015-01-01

    Acrylic resin is a widely used material in clinical practice, and a satisfactory biocompatibility is essential. When the resin polymerization reaction is incomplete, residual monomers are released into the oral cavity. The aim of this study was to evaluate, through a literature review, the cytotoxicity caused by the denture base acrylic resin used, and its components. The selection of published studies was performed on the Pubmed database from January 2008 to July 2013. The keywords used were: "cytotoxicity and acrylic resins", "cytotoxicity and denture base resins" and "cytotoxicity and oral prosthesis". Inclusion criteria were: in vitro studies and literature reviews published in English that evaluated the acrylic resin cytotoxicity for denture base and its components. Studies with no reference to the search strategy were excluded. A total of 182 articles were found. Among these, only 13 were included for writing this review. The MTT test is the most common test used to evaluate acrylic resin cytotoxicity. Auto-polymerized resin is more cytotoxic than heat-polymerized resin because of its higher quantity of residual monomers which cause cell and tissue changes in the oral mucosa. However, more studies are necessary for the development of biocompatible materials.

  1. Applications of Blue Light-curing Acrylic Resin to Forensic Sample Preparation and Microtomy.

    PubMed

    Groves, Ethan; Palenik, Christopher S

    2016-03-01

    This study discusses the results of an evaluation of a one-part blue light-curing acrylic resin for embedding trace evidence prior to the preparation of thin sections with a microtome. Through a comparison to several epoxy resins, the physical properties relevant to both trace evidence examination and analytical microscopy in general, including as viscosity, clarity, color, hardness, and cure speed, were explored. Finally, thin sections from paint samples embedded in this acrylic resin were evaluated to determine if, through smearing or impregnation, the resin contributed to the infrared spectra. The results of this study show that blue light-curing acrylic resins provide the desired properties of an embedding medium, generate high-quality thin sections, and can significantly simplify the preparation of paint chips, fibers and a multitude of other types of microscopic samples in the forensic trace evidence laboratory.

  2. Applications of Blue Light-curing Acrylic Resin to Forensic Sample Preparation and Microtomy.

    PubMed

    Groves, Ethan; Palenik, Christopher S

    2016-03-01

    This study discusses the results of an evaluation of a one-part blue light-curing acrylic resin for embedding trace evidence prior to the preparation of thin sections with a microtome. Through a comparison to several epoxy resins, the physical properties relevant to both trace evidence examination and analytical microscopy in general, including as viscosity, clarity, color, hardness, and cure speed, were explored. Finally, thin sections from paint samples embedded in this acrylic resin were evaluated to determine if, through smearing or impregnation, the resin contributed to the infrared spectra. The results of this study show that blue light-curing acrylic resins provide the desired properties of an embedding medium, generate high-quality thin sections, and can significantly simplify the preparation of paint chips, fibers and a multitude of other types of microscopic samples in the forensic trace evidence laboratory. PMID:27404623

  3. The creep behavior of acrylic denture base resins.

    PubMed

    Sadiku, E R; Biotidara, F O

    1996-01-01

    The creep behavior of acrylic dental base resins, at room temperature and at different loading conditions, has been examined. The behaviors of these resins are similar to that of "commercial perspex" at room temperature over a period of 1000 seconds. The pseudo-elastic moduli of the blends of PMMA VC show a significant increase compared with PMMA alone. The addition of the PVC powder to the heat-cured acrylic resin increased the time-dependent elastic modulus. This increase in elastic modulus is advantageous in the production of denture based resins of improv mechanical properties.

  4. Acrylic resin injection method for blood vessel investigations.

    PubMed

    Suwa, Fumihiko; Uemura, Mamoru; Takemura, Akimichi; Toda, Isumi; Fang, Yi-Ru; Xu, Yuan Jin; Zhang, Zhi Yuan

    2013-01-01

    The injection of acrylic resin into vessels is an excellent method for macroscopically and microscopically observing their three-dimensional features. Conventional methods can be enhanced by removal of the polymerization inhibitor (hydroquinone) without requiring distillation, a consistent viscosity of polymerized resin, and a constant injection pressure and speed. As microvascular corrosion cast specimens are influenced by viscosity, pressure, and speed changes, injection into different specimens yields varying results. We devised a method to reduce those problems. Sodium hydroxide was used to remove hydroquinone from commercial methylmethacrylate. The solid polymer and the liquid monomer were mixed using a 1 : 9 ratio (low-viscosity acrylic resin, 9.07 ± 0.52 mPa•s) or a 3:7 ratio (high-viscosity resin, 1036.33 ± 144.02 mPa•s). To polymerize the acrylic resin for injection, a polymerization promoter (1.0% benzoyl peroxide) was mixed with a polymerization initiator (0.5%, N, N-dimethylaniline). The acrylic resins were injected using a precise syringe pump, with a 5-mL/min injection speed and 11.17 ± 1.60 mPa injection pressure (low-viscosity resin) and a 1-mL/min injection speed and 58.50 ± 5.75 mPa injection pressure (high-viscosity resin). Using the aforementioned conditions, scanning electron microscopy indicated that sufficient resin could be injected into the capillaries of the microvascular corrosion cast specimens.

  5. 21 CFR 177.1340 - Ethylene-methyl acrylate copolymer resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ethylene-methyl acrylate copolymer resins. 177...-methyl acrylate copolymer resins. Ethylene-methyl acrylate copolymer resins may be safely used as... prescribed conditions: (a) For the purpose of this section, the ethylene-methyl acrylate copolymer...

  6. 21 CFR 177.1340 - Ethylene-methyl acrylate copolymer resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-methyl acrylate copolymer resins. 177.1340... copolymer resins. Ethylene-methyl acrylate copolymer resins may be safely used as articles or components of...) For the purpose of this section, the ethylene-methyl acrylate copolymer resins consist of...

  7. Effect of curing cycle on the tensile strength of the bond between heat cured denture base acrylic resin and acrylic resin denture teeth.

    PubMed

    Dalal, Ayesha; Juszczyk, Andrzej S; Radford, David R; Clark, Robert K F

    2009-12-01

    The effect of different curing cycles on the tensile strength of the bond between one brand of cross-linked acrylic resin teeth and three heat cured denture base acrylic resins was tested. There were differences in the tensile bond strength between the three heat cured denture base acrylic resins and the three curing cycles used. The bond strength of the acrylic resin denture base material made by the same manufacturer as the cross-linked acrylic resin denture teeth was higher. The bond strength following the short cycle was lowest in all cases, individual differences between curing cycles failed to reach statistical significance. PMID:20158054

  8. Performance comparison of acrylic and thiol-acrylic resins in two-photon polymerization.

    PubMed

    Jiang, Lijia; Xiong, Wei; Zhou, Yushen; Liu, Ying; Huang, Xi; Li, Dawei; Baldacchini, Tommaso; Jiang, Lan; Lu, Yongfeng

    2016-06-13

    Microfabrication by two-photon polymerization is investigated using resins based on thiol-ene chemistry. In particular, resins containing different amounts of a tetrafunctional acrylic monomer and a tetrafunctional thiol molecule are used to create complex microstructures. We observe the enhancement of several characteristics of two-photon polymerization when using thiol-acrylic resins. Specifically, microfabrication is carried out using higher writing velocities and it produces stronger polymeric microstructures. Furthermore, the amount of shrinkage typically observed in the production of three-dimensional microstructures is reduced also. By means of microspectrometry, we confirm that the thiol-acrylate mixture in TPP resins promote monomer conversion inducing a higher degree of cross-linked network formation.

  9. Performance comparison of acrylic and thiol-acrylic resins in two-photon polymerization.

    PubMed

    Jiang, Lijia; Xiong, Wei; Zhou, Yushen; Liu, Ying; Huang, Xi; Li, Dawei; Baldacchini, Tommaso; Jiang, Lan; Lu, Yongfeng

    2016-06-13

    Microfabrication by two-photon polymerization is investigated using resins based on thiol-ene chemistry. In particular, resins containing different amounts of a tetrafunctional acrylic monomer and a tetrafunctional thiol molecule are used to create complex microstructures. We observe the enhancement of several characteristics of two-photon polymerization when using thiol-acrylic resins. Specifically, microfabrication is carried out using higher writing velocities and it produces stronger polymeric microstructures. Furthermore, the amount of shrinkage typically observed in the production of three-dimensional microstructures is reduced also. By means of microspectrometry, we confirm that the thiol-acrylate mixture in TPP resins promote monomer conversion inducing a higher degree of cross-linked network formation. PMID:27410383

  10. Colour Stability of Heat and Cold Cure Acrylic Resins

    PubMed Central

    Ganesh, P R; Reddy, Madan Mohan; Ebenezar, A.V. Rajesh; Sivakumar, G

    2015-01-01

    Introduction: To evaluate the colour stability of heat and cold cure acrylic resins under simulated oral conditions with different colorants. Materials and Methods: Three different brands of heat cure acrylic resin and two rapid cure auto polymerizing acrylic resin of commercial products such as Trevelon Heat Cure (THC), DPI Heat cure (DHC), Pyrax Heat Cure (PHC), DPI Cold cure (DCC) and Acralyn-R-Cold cure (ACC) have been evaluated for discoloration and colour variation on subjecting it to three different, commonly employed food colorants such as Erythrosine, Tartarizine and Sunset yellow. In order to simulate the oral condition the food colorants were diluted with artificial saliva to the samples taken up for the study. These were further kept in an incubator at 37°C ± 1°C. The UV-visible spectrophotometer has been utilized to evaluate the study on the basis of CIE L* a* b* system. The prepared samples for standard evaluation have been grouped as control group, which has been tested with a white as standard, which is applicable for testing the colour variants. Results: The least colour changes was found to be with Sunset Yellow showing AE* value of 3.55 with heat cure acrylic resin branded as PHC material and the highest colour absorption with Tartarizine showing AE* value of 12.43 in rapid cure autopolymerzing acrylic resin material branded as ACC material. Conclusion: ACC which is a self cure acrylic resin shows a higher colour variation to the tartarizine food coloration. There were not much of discoloration values shown on the denture base resins as the food colorants are of organic azodyes. PMID:25738078

  11. [Acrylic resin reinforcement with metallic and nonmetallic inserts].

    PubMed

    Preoteasa, Elena; Murariu, Cătălina Măgureanu; Ionescu, Ecaterina; Preoteasa, Cristina Teodora

    2007-01-01

    In the current use of acrylic resin for removable dentures and orthodontic treatments we are frequently facing the fact of base fracture. The repairing of this, determine most of the time, discomfort of the patient, by excluding the prosthetic device, affecting the treatment, loosing patient's time, doctor's time, implying the dental laboratory and extra expenses. The causes of fractures are many, from clinical cases with some specific anatomic and functional particularities, or parafunctional, to the incorrect designing, manufacturing or wearing of the prosthetic part, being connected with the materials characteristics. The consequences and costs of these fractures are leading to unsatisfying results in some of the clinical cases, in presence of parafunctions like bruxism or clenching and specifically for the new types of prosthetic rehabilitation, on natural teeth or implants. PMID:17983190

  12. 21 CFR 177.1340 - Ethylene-methyl acrylate copolymer resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ethylene-methyl acrylate copolymer resins. 177... for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1340 Ethylene-methyl acrylate copolymer resins. Ethylene-methyl acrylate copolymer resins may be safely used...

  13. 21 CFR 177.1340 - Ethylene-methyl acrylate copolymer resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ethylene-methyl acrylate copolymer resins. 177... for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1340 Ethylene-methyl acrylate copolymer resins. Ethylene-methyl acrylate copolymer resins may be safely used...

  14. 21 CFR 177.1340 - Ethylene-methyl acrylate copolymer resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ethylene-methyl acrylate copolymer resins. 177... Repeated Use Food Contact Surfaces § 177.1340 Ethylene-methyl acrylate copolymer resins. Ethylene-methyl... section, the ethylene-methyl acrylate copolymer resins consist of basic copolymers produced by...

  15. Dimensional stability of autopolymerizing acrylic resin impression trays.

    PubMed

    Fehling, A W; Hesby, R A; Pelleu, G B

    1986-05-01

    A study was undertaken to determine the optimal interval between fabrication of an autopolymerizing acrylic resin custom impression tray and making a final impression. Twenty mandibular arch-shaped trays, 10 each of Fastray and Formatray resin, were evaluated for dimensional change. Both materials behaved similarly. Cross-arch contraction of the borders of buccal flanges and unilateral expansion of the borders of buccal-to-lingual flanges were observed. These changes indicate distortion. Linear dimensional changes occurred throughout 6 hours, which suggests that any impression made in a methyl methacrylate acrylic resin custom impression tray should be poured as soon as is conveniently possible. Significant linear dimensional changes were observed for only 40 minutes from the initiation of tray fabrication. This study concludes that while an aged tray is preferred, it is acceptable to make an impression in an autopolymerizing resin custom impression tray after 40 minutes.

  16. Industrially relevant epoxy-acrylate hybrid resin photopolymerizations

    NASA Astrophysics Data System (ADS)

    Ajiboye, Gbenga I.

    Photopolymerization of epoxy-acrylate hybrid resins takes advantages of inherent properties present in the free-radical and cationic reactions to reduce oxygen inhibition problems that plague free-radical reactions. Similarly, the combined reaction mechanisms reduce moisture sensitivity of the cationic reactions. Despite the advantages of epoxy-acrylate hybrid resins, problems persist that need to be addressed. For example, low conversion and polymerization rate of the epoxides are a problem, because the fast acrylate conversion prevents the epoxide from reaching high conversion. Controlling phase separation is challenging, since two moieties with different properties are reacting. The physical properties of the polymer will be impacted by the availability of different moieties. High shrinkage stress results from the acrylate moiety, causing buckling and cracking in film and coating applications. The overall goal of this study is to use the fundamental knowledge of epoxy-acrylate hybrid resins to formulate industrially viable polymers. In order to achieve this goal, the study focuses on the following objectives: (I) determine the apparent activation energy of the hybrid monomer METHB, (II) increase epoxide conversion and polymerization rate of hybrid formulations, and (III) control physical properties in epoxy-acrylate hybrid resins. In order to increase the epoxide conversion and rate of polymerization, the sensitivity of epoxides to alcohol is used to facilitate the activated monomer (AM) mechanism and induce a covalent bond between the epoxide and acrylate polymers through the hydroxyl group. It is hypothesized that if the AM mechanism is facilitated, epoxide conversion will increase. As a result, the resins can be tailored to control phase separation and physical properties, and shrinkage stress can be reduced. In pursuit of these objectives, the hybrid monomer METHB was polymerized at temperatures ranging from 30°C to 70°C to obtain apparent activation

  17. Bond strength between acrylic resin and maxillofacial silicone

    PubMed Central

    HADDAD, Marcela Filié; GOIATO, Marcelo Coelho; dos SANTOS, Daniela Micheline; CREPALDI, Nádia de Marchi; PESQUEIRA, Aldiéris Alves; BANNWART, Lisiane Cristina

    2012-01-01

    The development of implant dentistry improved the possibilities of rehabilitation with maxillofacial prosthesis. However, clinically it is difficult to bond the silicone to the attachment system. Objectives This study aimed to evaluate the effect of an adhesive system on the bond strength between acrylic resin and facial silicone. Material and Methods A total of 120 samples were fabricated with auto-polymerized acrylic resin and MDX 4-4210 facial silicone. Both materials were bonded through mechanical retentions and/or application of primers (DC 1205 primer and Sofreliner primer S) and adhesive (Silastic Medical Adhesive Type A) or not (control group). Samples were divided into 12 groups according to the method used to attach the silicone to the acrylic resin. All samples were subjected to a T-peel test in a universal testing machine. Failures were classified as adhesive, cohesive or mixed. The data were evaluated by the analysis of variance (ANOVA) and the Tukey's HSD test (α=.05). Results The highest bond strength values (5.95 N/mm; 3.07 N/mm; 4.75 N/mm) were recorded for the samples that received a Sofreliner primer application. These values were significantly higher when the samples had no scratches and did not receive the application of Silastic Medical Adhesive Type A. Conclusions The most common type of failure was adhesive. The use of Sofreliner primer increased the bond strength between the auto-polymerized acrylic resin and the Silastic MDX 4-4210 facial silicone. PMID:23329247

  18. Coating compositions for solar selective absorption comprising a thermosetting acrylic resin and particles of a low molecular weight fluorocarbon polymer

    SciTech Connect

    Maki, M.; Fukuda, H.; Sano, S.

    1984-01-17

    A coating composition for solar selective absorption comprising, in solvent, particles of an inorganic black pigment dispersed in a dissolved binder of a thermosetting acrylic resin and particles of a low molecular weight fluorocarbon resin contained in an amount of 5-15 parts by weight per 100 parts by weight of the acrylic resin. The inorganic black particles have a size of 0.01-0.5 microns and are contained in an amount of 45-65 parts by weight per 100 parts by weight of the acrylic resin. An article having a metal substrate and a paint film formed thereon from the composition in a dry thickness of 1.5 microns or more is also described.

  19. [Adaptation of acrylic resin dentures polymerized using various activation modes].

    PubMed

    Takamata, T; Inoue, Y; Hashimoto, K; Sugitou, S; Arakawa, H; Kurasawa, I

    1989-12-01

    The purpose of this in vitro study was to compare the dimensional accuracy of maxillary dentures made using a conventional heat-activated PMMA resin, a pour resin, a visible light-activated resin, and a microwave-activated acrylic resin. Two simple methods for measuring dimensional accuracy were used: (1) weight of impression material entrapped between the base and master die and (2) measurement of the posterior border gap at five locations. The volume of space between the denture base and the master die was determined by (1) computation and (2) estimation. Statistical analysis (Bartlett, ANOVA and Tukey's Tests) supported the following conclusions: (1) all groups showed a processing contraction, most apparent from buccal flange to buccal flange, (2) the poorest fitting group was processed in a brass flask and a water bath at a temperature which rose from 70 to 100 degrees C, using a heat activated resin (Acron), (3) the visible light activated resin (Triad) produced dentures of intermediate accuracy, as did Acupac 20 when either heat or microwave activated, (4) the two best fitting groups were prepared from a chemically activated resin system using pressure at low heat (PER form), and the resin developed for microwave activation (Acron MC).

  20. Cytotoxicity of denture base acrylic resins: a literature review.

    PubMed

    Jorge, Janaina Habib; Giampaolo, Eunice Teresinha; Machado, Ana Lúcia; Vergani, Carlos Eduardo

    2003-08-01

    Acrylic resins are widely used in the fabrication of denture bases and have been shown to be cytotoxic as a result of substances that leach from the resin. The primary eluate is residual monomer. Numerous reports suggest that residual monomer may be responsible for mucosal irritation and sensitization of tissues. This information is important, not only to assess the biologic effects of such materials, but also to enable a comparison among the different polymerization methods, thus assisting the clinician in selecting a material with minimal cytotoxicity. This article reviews the literature published from 1973 to 2000, selected by use of a Medline search, associated with cytotoxic effects usually ascribed to acrylic denture base materials.

  1. Fatigue properties of acrylic denture base resins.

    PubMed

    Fujii, K

    1989-12-01

    Observations were made of fractured surfaces caused by flexural and tensile fatigue tests made in polymethyl methacrylate denture base resins (PMMA). In addition, the changes in dynamic viscoelastic and tensile properties of the materials along with fatigue propagation were investigated. In the tensile and flexural fatigue tests, both the fractured surfaces, which had striations on their surfaces and cracks near the fractured section, closely resembled each other in appearance. On the other hand, all of the tensile properties, such as elastic modulus, toughness and tensile strength, decreased with the increase of the number of stress cycles in the fatigue test. The storage modulus (E') of the material decreased gradually along with fatigue propagation over the whole range of temperatures tested. The loss modulus (E") and mechanical loss tangent (tan delta) increased slightly. The fatigue limit of four commercial denture base resins varied widely from one product to another.

  2. Light-curing acrylic resin as an orthodontic baseplate material.

    PubMed

    Brown, J; Kerr, W J

    1998-08-01

    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.

  3. Radioluminescence of polyester resin modified with acrylic acid and its salts

    NASA Astrophysics Data System (ADS)

    Szalińska, H.; Wypych, M.; Pietrzak, M.; Szadkowska-Nicze, M.

    Polimal-109 polyester resin and its compounds containing acrylic acid and its salts such as: sodium, potassium, magnesium, calcium, barium, iron, cobalt, copper and manganese acrylates were studied by the radioluminescence method, including isothermal luminescence (ITL) at a radiation temperature of 77 K, thermoluminescence (RTL) and spectral distributions of isothermal luminescence. Measurements of optical absorption at 77 K before and after irradiation of the investigated samples were also carried out. The results obtained have shown that metal ions play a significant part in the processes taking place in the polyester matrix under the influence of γ 60Co radiation.

  4. A temporary space maintainer using acrylic resin teeth and a composite resin.

    PubMed

    Kochavi, D; Stern, N; Grajower, R

    1977-05-01

    A one-session technique for preparing a temporary space maintainer has been described. The technique consists of attaching an acrylic resin pontic to etched surfaces of natural adjacent teeth by means of a composite resin. The main advantages of this technique are elimination of premature tooth preparation, good esthetics, fair strength, low cost, and rapid completion of the restoration without the need of a dental laboratory.

  5. A Study on Effect of Surface Treatments on the Shear Bond Strength between Composite Resin and Acrylic Resin Denture Teeth.

    PubMed

    Chatterjee, Nirmalya; Gupta, Tapas K; Banerjee, Ardhendu

    2011-03-01

    Visible light-cured composite resins have become popular in prosthetic dentistry for the replacement of fractured/debonded denture teeth, making composite denture teeth on partial denture metal frameworks, esthetic modification of denture teeth to harmonize with the characteristics of adjacent natural teeth, remodelling of worn occlusal surfaces of posterior denture teeth etc. However, the researches published on the bond strength between VLC composite resins and acrylic resin denture teeth is very limited. The purpose of this study is to investigate the effect of five different methods of surface treatments on acrylic resin teeth on the shear bond strength between light activated composite resin and acrylic resin denture teeth. Ninety cylindrical sticks of acrylic resin with denture teeth mounted atop were prepared. Various treatments were done upon the acrylic resin teeth surfaces. The samples were divided into six groups, containing 15 samples each. Over all the treated and untreated surfaces of all groups, light-cured composite resin was applied. The shear strengths were measured in a Universal Testing Machine using a knife-edge shear test. Data were analyzed using one way analysis of variance (ANOVA) and mean values were compared by the F test. Application of bonding agent with prior treatment of methyl methacrylate on the acrylic resin denture teeth resulted in maximum bond strength with composite resin.

  6. [Determination of 9 residual acrylic monomers in acrylic resins by gas chromatography-mass spectrometry coupled with microwave assisted extraction].

    PubMed

    Lai, Ying; Lin, Rui; Cai, Luxin; Ge, Xiuxiu; Huang, Changchun

    2012-01-01

    A reliable gas chromatography-mass spectrometry (GC-MS) method was developed for the determination of 9 residual acrylic monomers (methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl acrylate, butyl methacrylate, styrene, acrylic acid and methacrylic acid) in acrylic resins. Solid resin was precipitated with methanol after microwave assisted extraction with ethyl acetate for 30 min, and liquid resin was diluted with methanol directly. The nine acrylic monomers got a good separation within 20 min on a DB-WAX column. The limits of quantification (LOQs, S/N = 10) of the method were in the range of 1-10 mg/kg for liquid resin and 3-50 mg/kg for solid resin. The calibration curves were linear within 1-500 mg/L range with correlation coefficients above 0. 995. The recoveries ranged from 84.4% to 108.6% at five spiked levels. The sensitivity, recovery and selectivity of the method can fully meet the requirements of practical work.

  7. Color stability, water sorption and cytotoxicity of thermoplastic acrylic resin for non metal clasp denture

    PubMed Central

    Jang, Dae-Eun; Lee, Ji-Young; Jang, Hyun-Seon; Lee, Jang-Jae

    2015-01-01

    PURPOSE The aim of this study was to compare the color stability, water sorption and cytotoxicity of thermoplastic acrylic resin for the non-metal clasp dentures to those of thermoplastic polyamide and conventional heat-polymerized denture base resins. MATERIALS AND METHODS Three types of denture base resin, which are conventional heat-polymerized acrylic resin (Paladent 20), thermoplastic polyamide resin (Bio Tone), thermoplastic acrylic resin (Acrytone) were used as materials for this study. One hundred five specimens were fabricated. For the color stability test, specimens were immersed in the coffee and green tee for 1 and 8 weeks. Color change was measured by spectrometer. Water sorption was tested after 1 and 8 weeks immersion in the water. For the test of cytotoxicity, cell viability assay was measured and cell attachment was analyzed by FE-SEM. RESULTS All types of denture base resin showed color changes after 1 and 8 weeks immersion. However, there was no significant difference between denture base resins. All specimens showed significant color changes in the coffee than green tee. In water sorption test, thermoplastic acrylic resin showed lower values than conventional heat-polymerized acrylic resin and thermoplastic polyamide resin. Three types of denture base showed low cytotoxicity in cell viability assay. Thermoplastic acrylic resin showed the similar cell attachment but more stable attachment than conventional heat-polymerized acrylic resin. CONCLUSION Thermoplastic acrylic resin for the non-metal clasp denture showed acceptable color stability, water sorption and cytotoxicity. To verify the long stability in the mouth, additional in vitro studies are needed. PMID:26330974

  8. Influence of ozone and paracetic acid disinfection on adhesion of resilient liners to acrylic resin

    PubMed Central

    2016-01-01

    PURPOSE The aim of this study was to evaluate the effect of paracetic acid (PAA) and ozone disinfection on the tensile bond strength (TBS) of silicone-based resilient liners to acrylic resins. MATERIALS AND METHODS One hundred and twenty dumbbell shaped heat-polymerized acrylic resins were prepared. From the mid segment of the specimens, 3 mm of acrylic were grinded off and separated parts were reattached by resilient liners. The specimens were divided into 2 control (control1, control7) and 4 test groups of PAA and ozone disinfection (PAA1, PAA7, ozone1 and ozone7; n=10). While control groups were immersed in distilled water for 10 min (control1) and 7 days (control7), test groups were subjected to PAA (16 g/L) or ozone rich water (4 mg/L) for 1 cycle (10 min for PAA and 60 min for ozone) per day for 7 days prior to tensile tests. Measurements of the TBS were analyzed using 3-way ANOVA and Tukey's HSD test. RESULTS Adhesive strength of Mollosil decreased significantly by application of ozone disinfection. PAA disinfection had no negative effect on the TBS values of Mollosil and Molloplast B to acrylic resin. Single application of ozone disinfection did not have any negative effect on TBS values of Molloplast B, but prolonged exposure to ozone decreased its adhesive strength. CONCLUSION The adhesion of resilient liners to acrylic was not adversely affected by PAA disinfection. Immersion in ozonated water significantly decreased TBS of Mollosil. Prolonged exposure to ozone negatively affects adhesion of Molloplast B to denture base materials. PMID:27555898

  9. Fluoride Release from Hollow Silica Microsphere-Containing Dental Restorative Acrylate Resin.

    PubMed

    Ji, Yuqin; Gao, Jun; Yin, Hengbo; Wang, Aili; Jiang, Tingshun; Wu, Gang; Wu, Zhanao

    2015-05-01

    Hollow silica microspheres with mesoporous shells were prepared by the sacrificial template method. Hollow silica microsphere-containing acrylate resin-based dental restoration materials were prepared by using hollow silica microspheres as NaF reservoirs. Fluoride release performances from naked hollow silica microspheres, acrylate resin, and hollow silica microsphere-containing acrylate resin-based dental restorative materials in an artificial saliva were investigated. The results showed that hollow silica microsphere-containing acrylate resin-based dental restorative materials had higher cumulative fluoride release quantities and sustained fluoride release rates than traditional acrylate resin-based dental restorative materials. Fluoride release could be tuned by changing the mesoporous shell thickness of hollow silica microsphere.

  10. Acrylic Resin Molding Based Head Fixation Technique in Rodents.

    PubMed

    Roh, Mootaek; Lee, Kyungmin; Jang, Il-Sung; Suk, Kyoungho; Lee, Maan-Gee

    2016-01-12

    Head fixation is a technique of immobilizing animal's head by attaching a head-post on the skull for rigid clamping. Traditional head fixation requires surgical attachment of metallic frames on the skull. The attached frames are then clamped to a stationary platform resulting in immobilization of the head. However, metallic frames for head fixation have been technically difficult to design and implement in general laboratory environment. In this study, we provide a novel head fixation method. Using a custom-made head fixation bar, head mounter is constructed during implantation surgery. After the application of acrylic resin for affixing implants such as electrodes and cannula on the skull, additional resins applied on top of that to build a mold matching to the port of the fixation bar. The molded head mounter serves as a guide rails, investigators conveniently fixate the animal's head by inserting the head mounter into the port of the fixation bar. This method could be easily applicable if implantation surgery using dental acrylics is necessary and might be useful for laboratories that cannot easily fabricate CNC machined metal head-posts.

  11. Color difference threshold determination for acrylic denture base resins.

    PubMed

    Ren, Jiabao; Lin, Hong; Huang, Qingmei; Liang, Qifan; Zheng, Gang

    2015-01-01

    This study aimed to set evaluation indicators, i.e., perceptibility and acceptability color difference thresholds, of color stability for acrylic denture base resins for a spectrophotometric assessing method, which offered an alternative to the visual method described in ISO 20795-1:2013. A total of 291 disk specimens 50±1 mm in diameter and 0.5±0.1 mm thick were prepared (ISO 20795-1:2013) and processed through radiation tests in an accelerated aging chamber (ISO 7491:2000) for increasing times of 0 to 42 hours. Color alterations were measured with a spectrophotometer and evaluated using the CIE L*a*b* colorimetric system. Color differences were calculated through the CIEDE2000 color difference formula. Thirty-two dental professionals without color vision deficiencies completed perceptibility and acceptability assessments under controlled conditions in vitro. An S-curve fitting procedure was used to analyze the 50:50% perceptibility and acceptability thresholds. Furthermore, perceptibility and acceptability against the differences of the three color attributes, lightness, chroma, and hue, were also investigated. According to the S-curve fitting procedure, the 50:50% perceptibility threshold was 1.71ΔE00 (r(2)=0.88) and the 50:50% acceptability threshold was 4.00 ΔE00 (r(2)=0.89). Within the limitations of this study, 1.71/4.00 ΔE00 could be used as perceptibility/acceptability thresholds for acrylic denture base resins.

  12. Effect of thermal cycling and disinfection on microhardness of acrylic resin denture base.

    PubMed

    Goiato, Marcelo Coelho; Dos Santos, Daniela Micheline; Baptista, Gabriella Trunckle; Moreno, Amália; Andreotti, Agda Marobo; Dekon, Stéfan Fiuza de Carvalho

    2013-04-01

    The purpose of this study was to investigate the effect of thermal cycling and disinfection on the microhardness of acrylic resins denture base. Four different brands of acrylic resins were evaluated: Onda Cryl, QC 20, Classico and Lucitone. Each brand of acrylic resin was divided into four groups (n = 7) according to the disinfection method (microwave, Efferdent, 4% chlorhexidine and 1% hypochlorite). Samples were disinfected during 60 days. Before and after disinfection, samples were thermal cycled between 5-55 °C with 30-s dwell times for 1000 cycles. The microhardness was measured using a microhardener, at baseline (B), after first thermal cycling (T1), after disinfection (D) and after second thermal cycling (T2). The microhardness values of all groups reduced over time. QC-20 acrylic resin exhibited the lowest microhardness values. At B and T1 periods, the acrylic resins exhibited statistically greater microhardness values when compared to D and T2 periods. It can be concluded that the microhardness values of the acrylic resins denture base were affected by the thermal cycling and disinfection procedures. However, all microhardness values obtained herein are within acceptable clinical limits for the acrylic resins.

  13. Flexural Strength of Cold and Heat Cure Acrylic Resins Reinforced with Different Materials

    PubMed Central

    Heidari, Bijan; Firouz, Farnaz; Izadi, Alireza; Ahmadvand, Shahbaz

    2015-01-01

    Objectives: Heat-polymerized acrylic resin has been the most commonly used denture base material for over 60 years. However, the mechanical strength of acrylic resin is not adequate for long-term clinical performance of dentures. Consequently, fracture is a common clinical occurrence, which often develops in the midline of the denture base. This study aimed to evaluate the efficacy of cold-cure and heat-cure acrylic resins, reinforced with glass fibers, polyethylene fibers, and metal wire for denture base repair. Materials and Methods: Ninety specimens were prepared and allocated to nine groups. Ten specimens were considered as controls, and 80 were divided into 8 experimental groups. In the experimental groups, the specimens were sectioned into two halves from the middle, and were then divided into two main groups: one group was repaired with heat cure acrylic resin, and the other with cold cure acrylic resin. Each group was divided into 4 subgroups: unreinforced, reinforced with glass fibers, polyethylene fibers, and metal wire. All specimens were subjected to a 3-point bending test, and the flexural strength was calculated. Results: The group repaired with heat cure acrylic resin and reinforced with glass fiber showed the highest flexural strength; however, the group repaired with cold cure acrylic resin and reinforced with polyethylene fibers had the lowest flexural strength. There was no significant difference between the groups repaired with heat cure and cold cure acrylic resins without reinforcement. Conclusion: Repairing denture base with heat cure acrylic resin, reinforced with glass fibers increases the flexural strength of denture base. PMID:26877726

  14. An ORMOSIL-containing orthodontic acrylic resin with concomitant improvements in antimicrobial and fracture toughness properties.

    PubMed

    Gong, Shi-qiang; Epasinghe, Jeevani; Rueggeberg, Frederick A; Niu, Li-na; Mettenberg, Donald; Yiu, Cynthia K Y; Blizzard, John D; Wu, Christine D; Mao, Jing; Drisko, Connie L; Pashley, David H; Tay, Franklin R

    2012-01-01

    Global increase in patients seeking orthodontic treatment creates a demand for the use of acrylic resins in removable appliances and retainers. Orthodontic removable appliance wearers have a higher risk of oral infections that are caused by the formation of bacterial and fungal biofilms on the appliance surface. Here, we present the synthetic route for an antibacterial and antifungal organically-modified silicate (ORMOSIL) that has multiple methacryloloxy functionalities attached to a siloxane backbone (quaternary ammonium methacryloxy silicate, or QAMS). By dissolving the water-insoluble, rubbery ORMOSIL in methyl methacrylate, QAMS may be copolymerized with polymethyl methacrylate, and covalently incorporated in the pressure-processed acrylic resin. The latter demonstrated a predominantly contact-killing effect on Streptococcus mutans ATCC 36558 and Actinomyces naselundii ATCC 12104 biofilms, while inhibiting adhesion of Candida albicans ATCC 90028 on the acrylic surface. Apart from its favorable antimicrobial activities, QAMS-containing acrylic resins exhibited decreased water wettability and improved toughness, without adversely affecting the flexural strength and modulus, water sorption and solubility, when compared with QAMS-free acrylic resin. The covalently bound, antimicrobial orthodontic acrylic resin with improved toughness represents advancement over other experimental antimicrobial acrylic resin formulations, in its potential to simultaneously prevent oral infections during appliance wear, and improve the fracture resistance of those appliances.

  15. An ORMOSIL-Containing Orthodontic Acrylic Resin with Concomitant Improvements in Antimicrobial and Fracture Toughness Properties

    PubMed Central

    Rueggeberg, Frederick A.; Niu, Li-na; Mettenberg, Donald; Yiu, Cynthia K. Y.; Blizzard, John D.; Wu, Christine D.; Mao, Jing; Drisko, Connie L.; Pashley, David H.; Tay, Franklin R.

    2012-01-01

    Global increase in patients seeking orthodontic treatment creates a demand for the use of acrylic resins in removable appliances and retainers. Orthodontic removable appliance wearers have a higher risk of oral infections that are caused by the formation of bacterial and fungal biofilms on the appliance surface. Here, we present the synthetic route for an antibacterial and antifungal organically-modified silicate (ORMOSIL) that has multiple methacryloloxy functionalities attached to a siloxane backbone (quaternary ammonium methacryloxy silicate, or QAMS). By dissolving the water-insoluble, rubbery ORMOSIL in methyl methacrylate, QAMS may be copolymerized with polymethyl methacrylate, and covalently incorporated in the pressure-processed acrylic resin. The latter demonstrated a predominantly contact-killing effect on Streptococcus mutans ATCC 36558 and Actinomyces naselundii ATCC 12104 biofilms, while inhibiting adhesion of Candida albicans ATCC 90028 on the acrylic surface. Apart from its favorable antimicrobial activities, QAMS-containing acrylic resins exhibited decreased water wettability and improved toughness, without adversely affecting the flexural strength and modulus, water sorption and solubility, when compared with QAMS-free acrylic resin. The covalently bound, antimicrobial orthodontic acrylic resin with improved toughness represents advancement over other experimental antimicrobial acrylic resin formulations, in its potential to simultaneously prevent oral infections during appliance wear, and improve the fracture resistance of those appliances. PMID:22870322

  16. Color stability of acrylic resin adhesives with different initiation modes.

    PubMed

    Tanoue, Naomi; Koishi, Yoshikazu; Yanagida, Hiroaki; Atsuta, Mitsuru; Shimada, Kazuki; Matsumura, Hideo

    2004-09-01

    The purpose of this study was to evaluate the color stability of two acrylic resin adhesives with different activation systems: a benzoyl peroxide (BPO)-amine redox system and a tri-n-butylborane (TBB) derivative system. The colorimetric values of the two resins in different shades (Clear and Ivory) were determined (n=5) 24 hours after polymerization as a baseline using the L*a*b* system of the Commission Internationale de l'Eclairage (CIE). The specimens were thereafter immersed in distilled water, and the color difference (deltaE*) values were calculated. After 24 weeks, the TBB-initiated material showed a significantly (p<0.05) lower color change than the BPO-amine-initiated material. The deltaE* values for the BPO-amine-initiated materials were 6.9 for Clear and 15.8 for Ivory, whereas those for the TBB-initiated materials were 1.3 and 1.8 respectively. Thus, it was concluded that the TBB-initiated material had superior color stability to that of the BPO-amine-initiated material.

  17. Cytocompatible antifungal acrylic resin containing silver nanoparticles for dentures

    PubMed Central

    Acosta-Torres, Laura Susana; Mendieta, Irasema; Nuñez-Anita, Rosa Elvira; Cajero-Juárez, Marcos; Castaño, Víctor M

    2012-01-01

    Background Inhibition of Candida albicans on denture resins could play a significant role in preventing the development of denture stomatitis. The safety of a new dental material with antifungal properties was analyzed in this work. Methods Poly(methyl methacrylate) [PMMA] discs and PMMA-silver nanoparticle discs were formulated, with the commercial acrylic resin, Nature-CrylTM, used as a control. Silver nanoparticles were synthesized and characterized by ultraviolet-visible spectroscopy, dispersive Raman spectroscopy, and transmission electron microscopy. The antifungal effect was assessed using a luminescent microbial cell viability assay. Biocompatibility tests were carried out using NIH-3T3 mouse embryonic fibroblasts and a Jurkat human lymphocyte cell line. Cells were cultured for 24 or 72 hours in the presence or absence of the polymer formulations and analyzed using three different tests, ie, cellular viability by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and cell proliferation by enzyme-linked immunosorbent assay BrdU, and genomic DNA damage (Comet assay). Finally, the samples were evaluated mechanically, and the polymer-bearing silver nanoparticles were analyzed microscopically to evaluate dispersion of the nanoparticles. Results The results show that PMMA-silver nanoparticle discs significantly reduce adherence of C. albicans and do not affect metabolism or proliferation. They also appear not to cause genotoxic damage to cells. Conclusion The present work has developed a new biocompatible antifungal PMMA denture base material. PMID:22969297

  18. A Comparison of Shear Bond Strength of Ceramic and Resin Denture Teeth on Different Acrylic Resin Bases

    PubMed Central

    Corsalini, Massimo; Venere, Daniela Di; Pettini, Francesco; Stefanachi, Gianluca; Catapano, Santo; Boccaccio, Antonio; Lamberti, Luciano; Pappalettere, Carmine; Carossa, Stefano

    2014-01-01

    The purpose of this study is to compare the shear bond strength of different resin bases and artificial teeth made of ceramic or acrylic resin materials and whether tooth-base interface may be treated with aluminium oxide sandblasting. Experimental measurements were carried on 80 specimens consisting of a cylinder of acrylic resin into which a single tooth is inserted. An ad hoc metallic frame was realized to measure the shear bond strength at the tooth-base interface. A complete factorial plan was designed and a three-way ANalysis Of VAriance (ANOVA) was carried out to investigate if shear bond strength is affected by the following factors: (i) tooth material (ceramic or resin); (ii) base material (self-curing or thermal-curing resin); (iii) presence or absence of aluminium oxide sandblasting treatment at the tooth-base interface. Tukey post hoc test was also conducted to evaluate any statistically significant difference between shear strength values measured for the dif-ferently prepared samples. It was found from ANOVA that the above mentioned factors all affect shear strength. Furthermore, post hoc analysis indi-cated that there are statistically significant differences (p-value=0.000) between measured shear strength values for: (i) teeth made of ceramic material vs. teeth made of acrylic resin material; (ii) bases made of self-curing resin vs. thermal-curing resin; (iii) specimens treated with aluminium oxide sandblasting vs. untreated specimens. Shear strength values measured for acryl-ic resin teeth were on average 70% higher than those measured for ceramic teeth. The shear bond strength was maximized by preparing samples with thermal-curing resin bases and resin teeth submitted to aluminium oxide sandblasting. PMID:25614770

  19. A comparison of shear bond strength of ceramic and resin denture teeth on different acrylic resin bases.

    PubMed

    Corsalini, Massimo; Di Venere, Daniela; Pettini, Francesco; Stefanachi, Gianluca; Catapano, Santo; Boccaccio, Antonio; Lamberti, Luciano; Pappalettere, Carmine; Carossa, Stefano

    2014-01-01

    The purpose of this study is to compare the shear bond strength of different resin bases and artificial teeth made of ceramic or acrylic resin materials and whether tooth-base interface may be treated with aluminium oxide sandblasting. Experimental measurements were carried on 80 specimens consisting of a cylinder of acrylic resin into which a single tooth is inserted. An ad hoc metallic frame was realized to measure the shear bond strength at the tooth-base interface. A complete factorial plan was designed and a three-way ANalysis Of VAriance (ANOVA) was carried out to investigate if shear bond strength is affected by the following factors: (i) tooth material (ceramic or resin); (ii) base material (self-curing or thermal-curing resin); (iii) presence or absence of aluminium oxide sandblasting treatment at the tooth-base interface. Tukey post hoc test was also conducted to evaluate any statistically significant difference between shear strength values measured for the dif-ferently prepared samples. It was found from ANOVA that the above mentioned factors all affect shear strength. Furthermore, post hoc analysis indi-cated that there are statistically significant differences (p-value=0.000) between measured shear strength values for: (i) teeth made of ceramic material vs. teeth made of acrylic resin material; (ii) bases made of self-curing resin vs. thermal-curing resin; (iii) specimens treated with aluminium oxide sandblasting vs. untreated specimens. Shear strength values measured for acryl-ic resin teeth were on average 70% higher than those measured for ceramic teeth. The shear bond strength was maximized by preparing samples with thermal-curing resin bases and resin teeth submitted to aluminium oxide sandblasting.

  20. Epoxy and acrylate sterolithography resins: in-situ property measurements

    SciTech Connect

    Guess, T.R.; Chambers, R.S.; Hinnerichs, T.D.

    1996-01-01

    Stereolithography is a rapid prototyping method that is becoming an important product realization and concurrent engineering tool, with applications in advanced and agile manufacturing. During the build process, material behavior plays a significant role in the mechanics leading to internal stresses and, potentially, to distortion (curling) of parts. The goal of the ``Stereolithography Manufacturing Process Modeling and Optimization`` LDRD program was to develop engineering tools for improving overall part accuracy during the stereolithography build process. These tools include phenomenological material models of solidifying stereolithography photocurable resins and a 3D finite element architecture that incorporates time varying material behavior, laser path dependence, and structural linkage. This SAND report discusses the in situ measurement of shrinkage and force relaxation behavior of two photocurable resins, and the measurement of curl in simple cantilever beams. These studies directly supported the development of phenomenological material models for solidifying resins and provided experimental curl data to compare to model predictions.

  1. In vitro cytotoxicity of self-curing acrylic resins of different colors

    PubMed Central

    Retamoso, Luciana Borges; da Cunha, Taís de Morais Alves; Pithon, Matheus Melo; dos Santos, Rogério Lacerda; Martins, Fernanda Otaviano; Romanos, Maria Teresa Villela; Tanaka, Orlando Motohiro

    2014-01-01

    Objective The aim of this study was to assess the in vitro cytotoxicity of acrylic resins of different colors over time. Methods Specimens were divided into 4 groups (n = 6) according to the color of the acrylic resin (Orto Class, Clássico, Campinas, São Paulo, Brazil): Group 1: clear acrylic resin; group 2: pink acrylic resin; group 3: blue acrylic resin and group 4: green acrylic resin. All specimens were fabricated according to the mass manipulation technique and submitted to mechanical polishing protocol. The control was performed with an amalgam specimen (C+), a glass specimen (C-) and cell control (CC). Specimens were immersed in Minimum Eagle's Medium (MEM) and incubated for 24 h at 37ºC. The extracts from the experimental material were filtered and mixed with L929 fibroblast. Cytotoxicity was evaluated at 4 different times, 24, 48, 72 and 168 h. After contact, cells were incubated for 24 h and added to 100 µ of 0.01% neutral red dye. The cells were incubated for 3 h for pigment incorporation and fixed. Cells viability was determined by a spectroscopic (BioTek, Winooski, Vermont, USA) with a 492-nm wavelength λ=492 nm). Results There were no statistical differences between the experimental groups and the CC and C- groups. Conclusion Clear, pink, blue and green self-curing acrylic resins fabricated by means of the mass manipulation technique and mechanically polished are not cytotoxic. Neither the pigment added to the self-curing acrylic resin nor the factor of time influenced the cytotoxicity of the material. PMID:25279523

  2. Silver hollow optical fibers with acrylic silicone resin coating as buffer layer for sturdy structure

    NASA Astrophysics Data System (ADS)

    Iwai, Katsumasa; Takaku, Hiroyuki; Miyagi, Mitsunobu; Shi, Yi-Wei; Zhu, Xiao-Song; Matsuura, Yuji

    2016-03-01

    For sturdy silver hollow optical fibers, acrylic silicone resin is newly used as a buffer layer between an inner silver layer and a silica capillary. This acrylic silicone resin film prevents the glass surface from chemical and mechanical micro damages during silver plating process, which deteriorate mechanical strength of the hollow fibers. In addition, it keeps high adhesion of the silver layer with the glass surface. We discuss improvement of mechanical strength of the hollow glass fibers without deterioration of optical properties.

  3. Tensile bond strength between auto-polymerized acrylic resin and acrylic denture teeth treated with MF-MA solution

    PubMed Central

    2016-01-01

    PURPOSE This study evaluated the effect of chemical surface treatment using methyl formate-methyl acetate (MF-MA) solution on the tensile bond strength between acrylic denture teeth and auto-polymerized acrylic resin. MATERIALS AND METHODS Seventy maxillary central incisor acrylic denture teeth for each of three different brands (Yamahachi New Ace; Major Dent; Cosmo HXL) were embedded with incisal edge downwards in auto-polymerized resin in polyethylene pipes and ground with silicone carbide paper on their ridge lap surfaces. The teeth of each brand were divided into seven groups (n=10): no surface treatment (control group), MF-MA solution at a ratio of 25:75 (v/v) for 15 seconds, 30 seconds, 60 seconds, 120 seconds, 180 seconds, and MMA for 180 seconds. Auto-polymerized acrylic resin (Unifast Trad) was applied to the ground surface and polymerized in a pressure cooker. A tensile strength test was performed with a universal testing machine. Statistical analysis of the results was performed using two-way analysis of variance (ANOVA) and post-hoc Dunnett T3 test (α=.05). RESULTS The surface treatment groups had significantly higher mean tensile bond strengths compared with the control group (P<.05) when compared within the same brand. Among the surface treatment groups of each brand, there were no significantly different tensile bond strengths between the MF-MA groups and the MMA 180 second group (P>.05), except for the Yamahachi New Ace MF-MA 180-second group (P<.05). CONCLUSION 15-second MF-MA solution can be an alternative chemical surface treatment for repairing a denture base and rebonding acrylic denture teeth with auto-polymerized acrylic resin, for both conventional and cross-linked teeth. PMID:27555897

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

    PubMed

    Kamath, G; Bhargava, K

    2002-01-01

    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.

  5. Effect of sealant application and thermal cycling on bond strength of tissue conditioners to acrylic resin.

    PubMed

    Sampaio, Francisca Neta Cruz Soares; Pinto, José Renato Ribeiro; Turssi, Cecília Pedroso; Basting, Roberta Tarkany

    2013-01-01

    The aim of this study was to evaluate the effect of sealer application and thermal cycling on the bond strength between tissue conditioners and acrylic resin, and to observe the type of bond failure. Two hundred eighty-eight specimens (10x16x3 mm) were made of an acrylic resin (Lucitone 500, Dentsply) using a metal muffle. Specimens were divided into four groups according to the tissue conditioner (Coe-Comfort, GC or Dentusoft, Densell) used and whether or not a sealer (Eversoft Soft Liner Sealer, Myerson) was applied. Each of the four groups was subdivided into other six subgroups (n=12) to undergo thermocycling for 45, 90, 135, 180 or 210 cycles with a dwell time of 60 s, or to be left non thermocycled (control). Tensile bond strength was measured in a universal testing machine at a crosshead speed of 5 mm/min. Sealant application had no effect on the tensile bond strength of the relined acrylic resin, regardless of the tissue conditioner used (Coe-Comfort: p=0.306 and Dentusoft: p=0.1501). The number of thermal cycles had a significant effect on the tensile bond strength of the relined acrylic resin (Coe-Comfort: p=0.002 and Dentusoft: p<0.001). Both tissue conditioners presented similar bond strength to acrylic resin. For both tissue conditioners, sealer coatings had no influence on bond strength, while different numbers of thermal cycles affected that mechanical property.

  6. In Vitro Antifungal Evaluation of Seven Different Disinfectants on Acrylic Resins

    PubMed Central

    Yildirim-Bicer, A. Z.; Peker, I.; Akca, G.; Celik, I.

    2014-01-01

    Objective. The aim of this study was to evaluate alternative methods for the disinfection of denture-based materials. Material and Methods. Two different denture-based materials were included in the study. Before microbial test, the surface roughness of the acrylic resins was evaluated. Then, the specimens were divided into 8 experimental groups (n = 10), according to microorganism considered and disinfection methods used. The specimens were contaminated in vitro by standardized suspensions of Candida albicans ATCC#90028 and Candida albicans oral isolate. The following test agents were tested: sodium hypochlorite (NaOCl 1%), microwave (MW) energy, ultraviolet (UV) light, mouthwash containing propolis (MCP), Corega Tabs, 50% and 100% white vinegar. After the disinfection procedure, the number of remaining microbial cells was evaluated in CFU/mL. Kruskal-Wallis, ANOVA, and Dunn's test were used for multiple comparisons. Mann Whitney U test was used to compare the surface roughness. Results. Statistically significant difference (P < 0.05) was found between autopolymerised and heat-cured acrylic resins. The autopolymerised acrylic resin surfaces were rougher than surfaces of heat-cured acrylic resin. The most effective disinfection method was 100% white vinegar for tested microorganisms and both acrylic resins. Conclusion. This study showed that white vinegar 100% was the most effective method for tested microorganisms. This agent is cost-effective and easy to access and thus may be appropriate for household use. PMID:24995305

  7. Influence of Surface Modifications of Acrylic Resin Teeth on Shear Bond Strength with Denture Base Resin-An Invitro Study

    PubMed Central

    Krishnan, Madhusudan; Krishnan, Chitra Shankar; Azhagarasan, N.S.; Sampathkumar, Jayakrishnakumar; Ramasubramanian, Hariharan

    2015-01-01

    Background Debonding of artificial teeth from the denture base is an important issue for edentulous patients rehabilitated with conventional or implant supported complete dentures. Aim The purpose of this study was to evaluate shear bond strength between denture base resin and acrylic resin denture teeth subjected to three different surface modifications on the ridge lap area as compared to unmodified denture teeth. Materials and Methods Forty acrylic resin central incisor denture teeth were selected and randomly divided into four test groups. The teeth in each group were subjected to one of the three different surface modifications, namely, chemical treatment, sandblasting and placement of retentive grooves on the ridge lap area respectively, prior to packing of the denture base resin. The group with unmodified teeth served as control. Forty acrylic resin test blocks thus obtained were tested for shear bond strength between acrylic resin teeth and denture base resin in Universal Testing Machine. Data obtained was statistically analysed using one-way ANOVA and Student- Newman- Keul’s test (p< 0.05). Results Analysis of shear bond strength revealed that retentive grooves on the ridge lap area showed highest bond strength values followed by sandblasting and both were statistically significant compared to the control and chemically treated groups. Unmodified surface of the resin teeth showed the least bond strength. Conclusion Within the limitations of this invitro study the placement of retentive grooves or sandblasting of the ridge lap area showed highly significant improvement in shear bond strength compared to the unmodified surface. Chemical treatment did not result in any significant improvement in the shear bond strength compared to the unmodified surface. PMID:26501005

  8. Preparation and properties of acrylic resin coating modified by functional graphene oxide

    NASA Astrophysics Data System (ADS)

    Dong, Rui; Liu, Lili

    2016-04-01

    To improve the dispersion and the strength of filler-matrix interface in acrylic resin, the functional graphene oxide (FGO) was obtained by surface modification of graphene oxide (GO) by γ-methacryloxypropyl trimethoxysilane (KH-570) and then the acrylic nanocomposites containing different loadings of GO and FGO were prepared. The structure, morphology and dispersion/exfoliation of the FGO were characterized by XRD, FT-IR, Raman, XPS, SEM and TEM. The results demonstrated that the KH-570 was successfully grafted onto the surface of GO sheets. Furthermore, the corresponding thermal, mechanical and chemical resistance properties of the acrylic nanocomposites filled with the FGO were studied and compared with those of neat acrylic and GO/acrylic nanocomposites. The results revealed that the loading of FGO effectively enhanced various properties of acrylic resin. These findings confirmed that the dispersion and interfacial interaction were greatly improved by incorporation of FGO, which might be the result of covalent bonds between the FGO and the acrylic matrix. This work demonstrates an in situ polymerization method to construct a flexible interphase structure, strong interfacial interaction and good dispersion of FGO in acrylic nanocomposites, which can reinforce the polymer properties and be applied in research and industrial areas.

  9. The effect of various frequencies of ultrasonic cleaner in reducing residual monomer in acrylic resin.

    PubMed

    Charasseangpaisarn, Taksid; Wiwatwarrapan, Chairat

    2015-12-01

    Monomer remaining in denture base acrylic can be a major problem because it may cause adverse effects on oral tissue and on the properties of the material. The purpose of this study was to compare the effect of various ultrasonic cleaner frequencies on the amount of residual monomer in acrylic resin after curing. Forty-two specimens each of Meliodent heat-polymerized acrylic resin (M) and Unifast Trad Ivory auto-polymerized acrylic resin (U) were prepared according to their manufacturer's instructions and randomly divided into seven groups: Negative control (NC); Positive control (PC); and five ultrasonic treatment groups: 28 kHz (F1), 40 kHz (F2), 60 kHz (F3) (M=10 min, U=5 min), and 28 kHz followed by 60 kHz (F4: M=5 min per frequency, U=2.5 min per frequency, and F5: M=10 min followed by 5 min per frequency, U=5 min followed by 2.5 min per frequency). Residual monomer was determined by HPLC following ISO 20795-1. The data were analyzed by One-way ANOVA and Tukey HSD. There was significantly less residual monomer in the auto-polymerized acrylic resin in all ultrasonic treatment groups and the PC group than that of the NC group (p<0.05). However, the amount of residual monomer in group F3 was significantly higher than that of the F1, F4, and PC groups (p<0.05). In contrast, ultrasonic treatment did not reduce the amount of residual monomer in heat-polymerized acrylic resin (p>0.05). The amount of residual monomer in heat-polymerized acrylic resin was significantly lower than that of auto-polymerized acrylic resin. In conclusion, ultrasonic treatment at low frequencies is recommended to reduce the residual monomer in auto-polymerized acrylic resin and this method is more practical in a clinical situation than previously recommended methods because of reduced chairside time.

  10. Assessment of the flexural strength of two heat-curing acrylic resins for artificial eyes.

    PubMed

    Fernandes, Aline Ursula Rocha; Portugal, Aline; Veloso, Letícia Rocha; Goiato, Marcelo Coelho; Santos, Daniela Micheline dos

    2009-01-01

    Prosthetic eyes are artificial substitutes for the eyeball, made of heat-curing acrylic resin, serving to improve the esthetic appearance of the mutilated patient and his/her inclusion in society. The aim of this study was to assess the flexural strength of two heat-curing acrylic resins used for manufacturing prosthetic eyes. Thirty-six specimens measuring 64 x 10 x 3.3 mm were obtained and divided into four groups: acrylic resin for artificial sclera N1 (Artigos Odontológicos Clássico, São Paulo, SP, Brazil), heat-cure water technique (GI) and microwave-cured (GII); colorless acrylic resin for prosthetic eyes (Artigos Odontológicos Clássico, São Paulo, SP, Brazil), heat-cure water technique (GIII) and microwave-cured (GIV). Mechanical tests using three point loads were performed in a test machine (EMIC, São José dos Pinhais, PR, Brazil). The analysis of variance and the Tukey test were used to identify significant differences (p < 0.01). Groups GII and GIV presented, respectively, the highest (98.70 +/- 11.90 MPa) and lowest means (71.07 +/- 8.93 MPa), with a statistically significant difference. The cure method used for the prosthetic eye resins did not interfere in their flexural strength. It was concluded that all the resins assessed presented sufficient flexural strength values to be recommended for the manufacture of prosthetic eyes.

  11. Is the bond between acrylic resin denture teeth and denture base resin stronger if they are both made by the same manufacturer?

    PubMed

    Patil, Reshma; Juszczyk, Andrzej S; Radford, David R; Clark, Robert K F

    2010-03-01

    A previous study suggested that a stronger bond may be achieved between acrylic resin denture base material and acrylic denture teeth when both are made by the same manufacturer. Three denture base acrylic resins from three different manufacturers were bonded to three different acrylic resin denture teeth, one of which was manufactured by each of the manufacturers of the base material. In each group there was a trend that the bond strength achieved between the teeth and base material from the same manufacturer was higher than the unmatched pairs but statistical significance was not achieved. PMID:20397502

  12. Processing factors affecting the clarity of a rapid-curing clear acrylic resin.

    PubMed

    Keng, S B; Cruickshanks-Boyd, D W; Davies, E H

    1979-10-01

    The difficulty in repeatedly producing unblemished, clear acrylic resin in the dental laboratory has hindered its wider use, despite its many advantages over coloured material. Recently, rapid-cure dental acrylics have been introduced, which are available in both clear and coloured forms. This investigation examined various factors which may influence the production of unblemished, rapid-curing, clear acrylic resin. Utilizing a quantitative assessment of clarity, the most important factor influencing the clarity of the resin is shown to be the choice of separating medium. Tin-foil produces extremely high clarity, but alginate mould separator causes surface blanching. However, this surface blanching can be removed by polishing. Porosity, caused by too rapid curing, and stone model dryness are of only secondary importance. Possible water contamination of the monomer liquid due to accidental exposure only affects clarity at very high levels of contamination.

  13. Incorporation of antimicrobial macromolecules in acrylic denture base resins: a research composition and update.

    PubMed

    Sivakumar, Indumathi; Arunachalam, Kuthalingam Subbiah; Sajjan, Suresh; Ramaraju, Alluri Venkata; Rao, Bheemalingeshwara; Kamaraj, Bindu

    2014-06-01

    Contemporary research in acrylic denture base materials focuses on the development of a novel poly(methyl methacrylate) (PMMA) resin with antimicrobial properties. Although PMMA resin has fulfilled all the requirements of an ideal denture base material, its susceptibility to microbial colonization in the oral environment is a formidable concern to clinicians. Many mechanisms including the absence of ionic charge in the methyl methacrylate resins, hydrophobic interactions, electrostatic interactions, and mechanical attachment have been found to contribute to the formation of biofilm. The present article outlines the basic categories of potential antimicrobial polymer (polymeric biocides) formulations (modified PMMA resins) and considers their applicability, biological status, and usage potential over the coming years.

  14. The effect of monomer/polymer mixing ratio, time between mixing and packing of heat cured acrylic resin denture base material and bond assisting agents on the bond strength to acrylic resin denture teeth.

    PubMed

    Alshahrani, A M; Spithourakis, S A; Juszczyk, A S; Radford, D R; Clark, R K F

    2012-09-01

    The aim of the study was to investigate the effect of varying the monomer/polymer mixing ratio, the time from mixing to packing heat cured acrylic resin and the effect of two bond assisting agents on the strength of the bond between denture base acrylic resin and acrylic resin denture teeth. Statistical differences were found in bond strength with monomer/polymer ratio and time between mixing and packing with one of the heat cured resins investigated. The benefit of using the bonding agents was not demonstrated.

  15. Using acrylic resin tooth veneers in patients with an abnormal jaw relationship: a case report.

    PubMed

    Yang, Tsung-Chieh; Lan, Yi-Hao; Wang, Tong-Mei; Tu, Ching-Yu; Lin, Li-Deh

    2014-01-01

    This case report describes and evaluates a method of arranging artificial teeth in patients with an abnormal jaw relationship in which a wider maxillary arch opposes a narrower mandibular arch. First, the fossa of mandibular posterior teeth was positioned on the crest of the mandibular edentulous ridge. The maxillary posterior teeth were then placed palatally to maximize occlusal contacts with the opposing mandibular teeth. Finally, acrylic resin tooth veneers were attached on the buccal surface of posterior maxillary teeth to improve the arch discrepancy. This method addresses functional considerations with the inner aspect of teeth and esthetic considerations with acrylic resin tooth veneers.

  16. Development of palm oil-based UV-curable epoxy acrylate and urethane acrylate resins for wood coating application

    SciTech Connect

    Tajau, Rida; Mahmood, Mohd Hilmi; Salleh, Mek Zah; Salleh, Nik Ghazali Nik; Ibrahim, Mohammad Izzat; Yunus, Nurulhuda Mohd

    2014-02-12

    The trend of using renewable sources such as palm oil as raw material in radiation curing is growing due to the demand from the market to produce a more environmental friendly product. In this study, the radiation curable process was done using epoxy acrylate and urethane acrylate resins which are known as epoxidised palm olein acrylate (EPOLA) and palm oil based urethane acrylate (POBUA), respectively. The purpose of the study was to investigate curing properties and the application of this UV-curable palm oil resins for wood coating. Furthermore, the properties of palm oil based coatings are compared with the petrochemical-based compound such as ebecryl (EB) i.e. EB264 and EB830. From the experiment done, the resins from petrochemical-based compounds resulted higher degree of crosslinking (up to 80%) than the palm oil based compounds (up to 70%), where the different is around 10-15%. The hardness property from this two type coatings can reached until 50% at the lower percentage of the oligomer. However, the coatings from petrochemical-based have a high scratch resistance as it can withstand at least up to 3.0 Newtons (N) compared to the palm oil-based compounds which are difficult to withstand the load up to 1.0 N. Finally, the test on the rubber wood substrate showed that the coatings containing benzophenone photoinitiator give higher adhesion property and their also showed a higher glosiness property on the glass substrate compared to the coatings containing irgacure-819 photoinitiator. This study showed that the palm oil coatings can be a suitable for the replacement of petrochemicals compound for wood coating. The palm oil coatings can be more competitive in the market if the problems of using high percentage palm oil oligomer can be overcome as the palm oil price is cheap enough.

  17. Development of palm oil-based UV-curable epoxy acrylate and urethane acrylate resins for wood coating application

    NASA Astrophysics Data System (ADS)

    Tajau, Rida; Ibrahim, Mohammad Izzat; Yunus, Nurulhuda Mohd; Mahmood, Mohd Hilmi; Salleh, Mek Zah; Salleh, Nik Ghazali Nik

    2014-02-01

    The trend of using renewable sources such as palm oil as raw material in radiation curing is growing due to the demand from the market to produce a more environmental friendly product. In this study, the radiation curable process was done using epoxy acrylate and urethane acrylate resins which are known as epoxidised palm olein acrylate (EPOLA) and palm oil based urethane acrylate (POBUA), respectively. The purpose of the study was to investigate curing properties and the application of this UV-curable palm oil resins for wood coating. Furthermore, the properties of palm oil based coatings are compared with the petrochemical-based compound such as ebecryl (EB) i.e. EB264 and EB830. From the experiment done, the resins from petrochemical-based compounds resulted higher degree of crosslinking (up to 80%) than the palm oil based compounds (up to 70%), where the different is around 10-15%. The hardness property from this two type coatings can reached until 50% at the lower percentage of the oligomer. However, the coatings from petrochemical-based have a high scratch resistance as it can withstand at least up to 3.0 Newtons (N) compared to the palm oil-based compounds which are difficult to withstand the load up to 1.0 N. Finally, the test on the rubber wood substrate showed that the coatings containing benzophenone photoinitiator give higher adhesion property and their also showed a higher glosiness property on the glass substrate compared to the coatings containing irgacure-819 photoinitiator. This study showed that the palm oil coatings can be a suitable for the replacement of petrochemicals compound for wood coating. The palm oil coatings can be more competitive in the market if the problems of using high percentage palm oil oligomer can be overcome as the palm oil price is cheap enough.

  18. Morphological analysis and interleukin release in human gingival fibroblasts seeded on different denture base acrylic resins.

    PubMed

    Trubiani, O; Toniato, E; Di Iorio, D; Diomede, F; Merciaro, I; D' Arcangelo, C; Caputi, S

    2012-01-01

    The development of different types of materials with application in practice dentistry is an area of intense growth and research due to its importance in oral health. Among the diverse materials currently used in restoration or in dentures, the acrylic based resins have been widely employed. The release of toxic components and the changes on their physical and mechanical properties actually represent a goal of intensive research. In vivo analysis showed that the surface roughness of the acrylic resin represents a factor that could stimulate bacteria colonization and soft tissue inflammation. For this purpose, in this work, we have analyzed the cell response to acrylic based resins Ivoclar, Tokuso and Coldpack in basal conditions, unpolished, and after the polished procedure performed to reduce the surface roughness. Our in vitro results using human gingival fibroblasts (HGFs) showed a decrease of cell growth, evaluated by MTT assay starting at 24 h of incubation, in samples seeded on resins in basal conditions and after the polished procedure. This cell growth reduction was associated to evident morphological changes in unpolished materials. After 24 h of culture in presence of polished and unpolished resins a spontaneous release was present of pro-inflammatory cytokines such as interleukin-6 (IL-6) and -8 (IL-8), which was higher in unpolished resins, indicating that the polished procedure, minimizing the cytotoxicity process, could contribute to reduce the gingival inflammation processes.

  19. Effect of Nanoclay on Thermal Conductivity and Flexural Strength of Polymethyl Methacrylate Acrylic Resin

    PubMed Central

    Ghaffari, Tahereh; Barzegar, Ali; Hamedi Rad, Fahimeh; Moslehifard, Elnaz

    2016-01-01

    Statement of the Problem The mechanical and thermal properties of polymethyl methacrylate (PMMA) acrylic resin should be improved to counterweigh its structural deficiencies. Purpose The aim of this study was to compare the flexural strength and thermal conductivity of conventional acrylic resin and acrylic resin loaded with nanoclay. Materials and Method The methacrylate monomer containing the 0.5, 1 and 2 wt% of nanoclay was placed in an ultrasonic probe and mixed with the PMMA powder. Scanning electron microscopy was used to verify homogeneous distribution of particles. Twenty-four 20×20×200-mm cubic samples were prepared for flexural strength test; 18 samples containing nanoclay and 6 samples for the control group. Another 24 cylindrical samples of 38×25 mm were prepared for thermal conductivity test. One-way ANOVA was used for statistical analysis, followed by multiple-comparison test (Scheffé’s test). Statistical significance was set at p< 0.05. Results Increasing the concentration of nanoclay incorporated into the acrylic resin samples increased thermal conductivity but decreased flexural strength (p< 0.05). Conclusion Based on the results of this study, adding nanoclay particles to PMMA improved its thermal conductivity, while it had a negative effect on the flexural strength. PMID:27284557

  20. Do flexible acrylic resin lingual flanges improve retention of mandibular complete dentures?

    PubMed Central

    Ahmed Elmorsy, Ayman Elmorsy; Ahmed Ibraheem, Eman Mostafa; Ela, Alaa Aboul; Fahmy, Ahmed; Nassani, Mohammad Zakaria

    2015-01-01

    Objectives: The aim of this study was to compare the retention of conventional mandibular complete dentures with that of mandibular complete dentures having lingual flanges constructed with flexible acrylic resin “Versacryl.” Materials and Methods: The study sample comprised 10 completely edentulous patients. Each patient received one maxillary complete denture and two mandibular complete dentures. One mandibular denture was made of conventional heat-cured acrylic resin and the other had its lingual flanges made of flexible acrylic resin Versacryl. Digital force-meter was used to measure retention of mandibular dentures at delivery and at 2 weeks and 45 days following denture insertion. Results: The statistical analysis showed that at baseline and follow-up appointments, retention of mandibular complete dentures with flexible lingual flanges was significantly greater than retention of conventional mandibular dentures (P < 0.05). In both types of mandibular dentures, retention of dentures increased significantly over the follow-up period (P < 0.05). Conclusions: The use of flexible acrylic resin lingual flanges in the construction of mandibular complete dentures improved denture retention. PMID:26539387

  1. The bond between acrylic resin denture teeth and the denture base: recommendations for best practice.

    PubMed

    Radford, D R; Juszczyk, A S; Clark, R K F

    2014-02-01

    Failure of the bond between denture teeth and base acrylic resin has been shown to be a cause of denture failure leading to inconvenience and costly repair. The optimal combination of acrylic resin denture tooth, denture base material, laboratory protocol and processing method has not yet been established. Extensive research enables the following recommendations for best practice to be made. Adopt practices that maximise the strength of the bond: select appropriate denture teeth; select base acrylic resin from the same manufacturer as the denture teeth; remove the glaze from ridgelaps of the denture teeth; apply monomer to the ridgelaps of the denture teeth before packing the base acrylic resin dough; use the manufacturers' recommended liquid/powder ratio; follow the manufacturers' recommended curing cycle; allow the flask to cool slowly and rest before deflasking. Adopt practices that avoid factors detrimental to bond strength: remove all traces of wax from the ridge laps of the denture teeth; remove all traces of mould seal from the ridgelaps of the denture teeth. It is evident that a number of factors are involved which may assist or prevent formation of an adequate bond, suggesting that attention to detail by the dental technician may be the most critical factor.

  2. Effects of an acrylic resin tray on relative surface doses for 10 MV x ray beams

    SciTech Connect

    Wu, A.

    1980-09-01

    Relative surface doses (RSD) for 10 MV x rays were measured and analyzed with an acrylic resin block tray present in the beam. It was found that the secondary electron contamination becomes significant for large fields in isocentric set-ups. Medium and high Z filters are investigated and suggested to be used to reduce RSD.

  3. Shear bond strength between autopolymerizing acrylic resin and Co-Cr alloy using different primers.

    PubMed

    Sanohkan, Sasiwimol; Urapepon, Somchai; Harnirattisai, Choltacha; Sirisinha, Chakrit; Sunintaboon, Panya

    2012-01-01

    This study aimed to examine the shear bond strength between cobalt chromium alloy and autopolymerizing acrylic resin using experimental primers containing 5, 10, and 15 wt% of 4-methacryloxyethyl trimellitic anhydride or 1, 2, and 3 wt% of 3-methacryloxypropyl-trimethoxysilane comparison to 5 commercial primers (ML primers, Alloy primer, Metal/Zirconia primer, Monobond S, and Monobond plus). Sixty alloy specimens were sandblasted and treated with each primer before bonded with an acrylic resin. The control group was not primed. The shear bond strengths were tested and statistically compared. Specimens treated with commercial primers significantly increased the shear bond strength of acrylic resin to cobalt chromium alloy (p<0.05). The highest shear bond strength was found in the Alloy primer group. Among experimental group, using 10 wt% of 4-methacryloxyethyl trimellitic anhydride -or 2 wt% of 3-methacryloxypropyltrimethoxysilane enhanced highest shear bond strength. The experimental and commercial primers in this study all improved bonding of acrylic resin to cobalt chromium alloy.

  4. The bond between acrylic resin denture teeth and the denture base: recommendations for best practice.

    PubMed

    Radford, D R; Juszczyk, A S; Clark, R K F

    2014-02-01

    Failure of the bond between denture teeth and base acrylic resin has been shown to be a cause of denture failure leading to inconvenience and costly repair. The optimal combination of acrylic resin denture tooth, denture base material, laboratory protocol and processing method has not yet been established. Extensive research enables the following recommendations for best practice to be made. Adopt practices that maximise the strength of the bond: select appropriate denture teeth; select base acrylic resin from the same manufacturer as the denture teeth; remove the glaze from ridgelaps of the denture teeth; apply monomer to the ridgelaps of the denture teeth before packing the base acrylic resin dough; use the manufacturers' recommended liquid/powder ratio; follow the manufacturers' recommended curing cycle; allow the flask to cool slowly and rest before deflasking. Adopt practices that avoid factors detrimental to bond strength: remove all traces of wax from the ridge laps of the denture teeth; remove all traces of mould seal from the ridgelaps of the denture teeth. It is evident that a number of factors are involved which may assist or prevent formation of an adequate bond, suggesting that attention to detail by the dental technician may be the most critical factor. PMID:24557385

  5. [MORPHOLOGICAL FEATURES OF RAT MUCOUS MEMBRANE OF THE TONGUE EARLY AFFECTED BY ACRYLIC RESIN MONOMER].

    PubMed

    Davydenko, V; Nidzelskiy, M; Starchenko, I; Davydenko, A; Kuznetsov, V

    2016-03-01

    Base materials, made on the basis of various derivatives of acrylic and methacrylic acids, have been widely used in prosthetic dentistry. Free monomer, affecting the tissues of prosthetic bed and the whole body, is always found in dentures. Therefore, study of the effect of acrylic resins' monomer on mucous membrane of the tongue is crucial. Rat tongue is very similar to human tongue, and this fact has become the basis for selecting these animals to be involved into the experiment. The paper presents the findings related to the effect of "Ftoraks" base acrylic resin monomer on the state of rat mucous membrane of the tongue and its regeneration. The microscopy has found that the greatest changes in the mucous membrane of the tongue occur on day 3 and 7 day after applying the monomer and are of erosive and inflammatory nature. Regeneration of tongue epithelium slows down. PMID:27119844

  6. Evaluation of shrinkage polymerization and temperature of different acrylic resins used to splinting transfer copings in indirect impression technique

    NASA Astrophysics Data System (ADS)

    Franco, Ana Paula G. O.; Karam, Leandro Z.; Galvão, José R.; Kalinowski, Hypolito J.

    2015-09-01

    The aim of the present study was evaluate the shrinkage polymerization and temperature of different acrylic resins used to splinting transfer copings in indirect impression technique. Two implants were placed in an artificial bone, with the two transfer copings joined with dental floss and acrylic resins; two dental resins are used. Measurements of deformation and temperature were performed with Fiber Braggs grating sensor for 17 minutes. The results revealed that one type of resin shows greater values of polymerization shrinkage than the other. Pattern resins did not present lower values of shrinkage, as usually reported by the manufacturer.

  7. The effect of flexible acrylic resin on masticatory muscle activity in implant-supported mandibular overdentures: a controlled clinical trial

    PubMed Central

    Ibraheem, Eman Mostafa Ahmed; Nassani, Mohammad Zakaria

    2016-01-01

    Background It is not yet clear from the current literature to what extent masticatory muscle activity is affected by the use of flexible acrylic resin in the construction of implant-supported mandibular overdentures. Objective To compare masticatory muscle activity between patients who were provided with implant-supported mandibular overdentures constructed from flexible acrylic resin and those who were provided with implant-supported mandibular overdentures constructed from heat-cured conventional acrylic resin. Methods In this clinical trial, 12 completely edentulous patients were selected and randomly allocated into two equal treatment groups. Each patient in Group 1 received two implants to support a mandibular overdenture made of conventional acrylic resin. In Group 2, the patients received two implants to support mandibular overdentures constructed from “Versacryl” flexible acrylic resin. The maxillary edentulous arch for patients in both groups was restored by conventional complete dentures. For all patients, masseter and temporalis muscle activity was evaluated using surface electromyography (sEMG). Results The results showed a significant decrease in masticatory muscle activity among patients with implant-supported mandibular overdentures constructed from flexible acrylic resin. Conclusion The use of “Versacryl” flexible acrylic resin in the construction of implant-supported mandibular overdentures resulted in decreased masticatory muscle activity. PMID:26955445

  8. Coemulsion and electrodeposition properties of mixtures of cationic epoxy resin and cationic acrylic resin containing butoxymethylamide groups

    SciTech Connect

    Chinping Yang; Yahnhaur Chen . Dept. of Chemical Engineering)

    1993-10-15

    Butyl acrylate, styrene, N,N-dimethylaminoethylmethacrylate, and N-(n-butoxy-methyl) acrylamide were copolymerized to prepare a cationic acrylic copolymer (I) containing butoxymethylamide groups. This copolymer can be mixed with an epoxy-amine adduct (II), acetic acid, and deionized water to form a coemulsion containing two cationic resins. The electrophoretic codeposition of the coemulsion and physical and chemical properties of the deposited film were investigated. The resin composition of film deposited from coemulsion was determined by Fourier transform Infrared (FTIR) quantitative analysis to study the coemulsion and electrophoretic codeposition behavior. The applicability of this two-component coemulsion in primer-surfacer (pricer) electrodeposition paint was also discussed. The results indicate that at any coemulsion resin composition the resin composition of electrodeposited film is almost equal to the coemulsion resin composition. The throwing power of emulsion increases with increasing applied voltage, as expected. However, the throwing power of coemulsion is almost equal to that of the II emulsion but greater than that of the I emulsion. Furthermore, all cured films derived from mixtures of I/II show excellent adhesive strength, good hardness, and high levels of salt spray resistance.

  9. Antimicrobial activity of a quaternary ammonium methacryloxy silicate-containing acrylic resin: a randomised clinical trial

    PubMed Central

    Liu, Si-ying; Tonggu, Lige; Niu, Li-na; Gong, Shi-qiang; Fan, Bing; Wang, Liguo; Zhao, Ji-hong; Huang, Cui; Pashley, David H.; Tay, Franklin R.

    2016-01-01

    Quaternary ammonium methacryloxy silicate (QAMS)-containing acrylic resin demonstrated contact-killing antimicrobial ability in vitro after three months of water storage. The objective of the present double-blind randomised clinical trial was to determine the in vivo antimicrobial efficacy of QAMS-containing orthodontic acrylic by using custom-made removable retainers that were worn intraorally by 32 human subjects to create 48-hour multi-species plaque biofilms, using a split-mouth study design. Two control QAMS-free acrylic disks were inserted into the wells on one side of an orthodontic retainer, and two experimental QAMS-containing acrylic disks were inserted into the wells on the other side of the same retainer. After 48 hours, the disks were retrieved and examined for microbial vitality using confocal laser scanning microscopy. No harm to the oral mucosa or systemic health occurred. In the absence of carry-across effect and allocation bias (disks inserted in the left or right side of retainer), significant difference was identified between the percentage kill in the biovolume of QAMS-free control disks (3.73 ± 2.11%) and QAMS-containing experimental disks (33.94 ± 23.88%) retrieved from the subjects (P ≤ 0.001). The results validated that the QAMS-containing acrylic exhibits favourable antimicrobial activity against plaque biofilms in vivo. The QAMS-containing acrylic may also be used for fabricating removable acrylic dentures. PMID:26903314

  10. Antimicrobial activity of a quaternary ammonium methacryloxy silicate-containing acrylic resin: a randomised clinical trial.

    PubMed

    Liu, Si-ying; Tonggu, Lige; Niu, Li-na; Gong, Shi-qiang; Fan, Bing; Wang, Liguo; Zhao, Ji-hong; Huang, Cui; Pashley, David H; Tay, Franklin R

    2016-02-23

    Quaternary ammonium methacryloxy silicate (QAMS)-containing acrylic resin demonstrated contact-killing antimicrobial ability in vitro after three months of water storage. The objective of the present double-blind randomised clinical trial was to determine the in vivo antimicrobial efficacy of QAMS-containing orthodontic acrylic by using custom-made removable retainers that were worn intraorally by 32 human subjects to create 48-hour multi-species plaque biofilms, using a split-mouth study design. Two control QAMS-free acrylic disks were inserted into the wells on one side of an orthodontic retainer, and two experimental QAMS-containing acrylic disks were inserted into the wells on the other side of the same retainer. After 48 hours, the disks were retrieved and examined for microbial vitality using confocal laser scanning microscopy. No harm to the oral mucosa or systemic health occurred. In the absence of carry-across effect and allocation bias (disks inserted in the left or right side of retainer), significant difference was identified between the percentage kill in the biovolume of QAMS-free control disks (3.73 ± 2.11%) and QAMS-containing experimental disks (33.94 ± 23.88%) retrieved from the subjects (P ≤ 0.001). The results validated that the QAMS-containing acrylic exhibits favourable antimicrobial activity against plaque biofilms in vivo. The QAMS-containing acrylic may also be used for fabricating removable acrylic dentures.

  11. Effect of 5.25 % sodium hypochlorite on color stability of acrylic and silicone based soft liners and a denture base acrylic resin.

    PubMed

    Salloum, Alaa'a M

    2014-06-01

    The purpose of the current study was to investigate the effect of a chemical disinfectant (sodium hypochlorite 5.25 %) on color stability of a denture base acrylic resin and two processed soft denture lining materials of two different types (acrylic-based and silicone-based). Ten specimens from each type of materials tested were made (2 × 20 × 20 mm). All specimens were immersed in sodium hypochlorite (5.25 %). Colorimetric measurements for each specimen were taken before immersion, and after 24 h and 7 days of immersion. Color changes were evaluated using the CIE L*a*b* colorimetric system. Data were statistically analyzed with one-way analysis of variance (ANOVA) (α = 0.05). ANOVA was followed by Bonferroni test to determine which groups differed from each other. ΔE and ΔL* of the silicone-based liner at the 1st and 7th days of immersion were significantly more than of denture base acrylic resin and acrylic-based liner. Change in ΔL* values of denture base acrylic resin and acrylic-based liner was small and statistically insignificant after 24 h of its immersion. However, the increase in ΔL* values of the acrylic-based liner after 7 days of immersion was considerably more than of denture base acrylic resin. Color changes in denture base acrylic resin and soft denture liners tended to increase with longer immersion times, and the color stability of the soft denture liners was influenced by its chemical type.

  12. [Comparative analysis of tissue reaction to acrylic resin materials in studies on Wistar strain rats].

    PubMed

    Sobolewska, E

    1999-01-01

    The study takes up the issue of assessing rat tissue reaction to operatively inserted implants of different acrylic resin materials used in prosthetic dentistry. The materials subjected to analysis were polyacrylics: Vertex Soft, Vertex R.S., Vertex S.C., Superacryl and silicone material Molloplast B. The prolongation of life and the dynamic development of prosthetic treatment have caused removable dentures to be used longer and among more people. Polymerised acrylic resin material of these dentures is a potential pathogenic factor to the oral cavity mucosa which is in contact with it. As many as 20 to 70% of patients using removable acrylic dentures suffer from prosthetic stomatopathy. It is considered that the mucosa irritation may be caused by denture trauma, a mycotic infection or toxic action of some components of acrylic materials. Therefore the use of new generation acrylic materials in producing prosthetic dentures needs a precise assessment of undesirable local and systemic effects. A comparative analysis of the effect of correctly polymerised acrylic material on rat mucosa, parotid glands and lymphatic nodes was carried out. Systemic toxicity of these materials was assessed. Acrylic plates were prepared from the most often used acrylic resin materials in the Department of Prosthetic Dentistry PAM and a silicone material (these materials were polymerised precisely according to the producers instruction). Before implantation the plates underwent a thermodynamic analysis in order to ensure that the polymerisation process was carried out correctly and to determine thermal resistance of particular materials. Next sterile acrylic plates were implanted in rats under general anaesthesia. The animals were divided into 6 groups, 10 rats each. In four groups acrylic plates were implanted, in one group silicone material plates were implanted and it represented the comparative group, in one control group an incision of the buccal mucosa was made. The rats were

  13. [Comparative analysis of tissue reaction to acrylic resin materials in studies on Wistar strain rats].

    PubMed

    Sobolewska, E

    1999-01-01

    The study takes up the issue of assessing rat tissue reaction to operatively inserted implants of different acrylic resin materials used in prosthetic dentistry. The materials subjected to analysis were polyacrylics: Vertex Soft, Vertex R.S., Vertex S.C., Superacryl and silicone material Molloplast B. The prolongation of life and the dynamic development of prosthetic treatment have caused removable dentures to be used longer and among more people. Polymerised acrylic resin material of these dentures is a potential pathogenic factor to the oral cavity mucosa which is in contact with it. As many as 20 to 70% of patients using removable acrylic dentures suffer from prosthetic stomatopathy. It is considered that the mucosa irritation may be caused by denture trauma, a mycotic infection or toxic action of some components of acrylic materials. Therefore the use of new generation acrylic materials in producing prosthetic dentures needs a precise assessment of undesirable local and systemic effects. A comparative analysis of the effect of correctly polymerised acrylic material on rat mucosa, parotid glands and lymphatic nodes was carried out. Systemic toxicity of these materials was assessed. Acrylic plates were prepared from the most often used acrylic resin materials in the Department of Prosthetic Dentistry PAM and a silicone material (these materials were polymerised precisely according to the producers instruction). Before implantation the plates underwent a thermodynamic analysis in order to ensure that the polymerisation process was carried out correctly and to determine thermal resistance of particular materials. Next sterile acrylic plates were implanted in rats under general anaesthesia. The animals were divided into 6 groups, 10 rats each. In four groups acrylic plates were implanted, in one group silicone material plates were implanted and it represented the comparative group, in one control group an incision of the buccal mucosa was made. The rats were

  14. Effects of acrylic resin monomers on porcine coronary artery reactivity.

    PubMed

    Abebe, Worku; West, Daniel; Rueggeberg, Frederick A; Pashley, David; Mozaffari, Mahmood S

    2016-07-01

    The purpose of the present investigation was to assess the reactivity of porcine coronary arteries under in vitro conditions following their exposure to methyl methacrylate (MMA) and hydroxyethyl methacrylate (HEMA) monomers. Confirming previous studies using rat aortas, both MMA and HEMA induced acute/direct relaxation of coronary ring preparations, which was partly dependent on the endothelium. With prolonged tissue exposure, both monomers caused time- and concentration-dependent inhibition of receptor-mediated contraction of the vascular smooth muscle caused by prostaglandin F2∝ (PGF2∝), with HEMA causing more inhibition than MMA. Hydroxyethyl methacrylate, but not MMA, also produced impairment of non-receptor-mediated contraction of the coronary smooth muscle induced by KCl. On the other hand, neither HEMA nor MMA altered relaxation of the smooth muscle produced by the direct-acting pharmacological agent, sodium nitroprusside (SNP). While exposure to HEMA impaired endothelium-dependent vasorelaxation caused by bradykinin (BK), MMA markedly enhanced this endothelial-mediated response of the arteries. The enhanced endothelial response produced by MMA was linked to nitric oxide (NO) release. In conclusion, with prolonged tissue exposure, MMA causes less pronounced effects/adverse consequences on coronary smooth muscle function relative to the effect of HEMA, while enhancing vasorelaxation associated with release of NO from the endothelium. Accordingly, MMA-containing resin materials appear to be safer for human applications than materials containing HEMA.

  15. Effect of silver nanoparticles incorporation on viscoelastic properties of acrylic resin denture base material

    PubMed Central

    Mahross, Hamada Zaki; Baroudi, Kusai

    2015-01-01

    Objective: The objective was to investigate the effect of silver nanoparticles (AgNPs) incorporation on viscoelastic properties of acrylic resin denture base material. Materials and Methods: A total of 20 specimens (60 × 10 × 2 mm) of heat cured acrylic resin were constructed and divided into four groups (five for each), according to the concentration of AgNPs (1%, 2%, and 5% vol.) which incorporated into the liquid of acrylic resin material and one group without additives (control group). The dynamic viscoelastic test for the test specimens was performed using the computerized material testing system. The resulting deflection curves were analyzed by material testing software NEXYGEN MT. Results: The 5% nanoparticles of silver (NAg) had significantly highest mean storage modulus E’ and loss tangent Tan δ values followed by 2% NAg (P < 0.05). For 1% nanosilver incorporation (group B), there were no statistically significant differences in storage modulus E’, lost modulus E” or loss tangent Tan δ with other groups (P > 0.05). Conclusion: The AgNPs incorporation within the acrylic denture base material can improve its viscoelastic properties. PMID:26038651

  16. Epoxy and acrylate stereolithography resins: In-situ measurements of cure shrinkage and stress relaxation

    SciTech Connect

    Guess, T.R.; Chambers, R.S.; Hinnerichs, T.D.; McCarty, G.D.; Shagam, R.N.

    1995-03-01

    Cross-sections of resin strands. Techniques were developed to make in situ measurements of gelled resin to determine linear shrinkage, stress-strain response and stress relaxation of single strands of SL 5170 epoxy and SL 5149 photocurable resins. Epoxy strands shrank approximately 1.4% and the acrylate strands about 1.0% after a single exposure. No forces were measured during cure shrinkage of strands following the first laser exposure. In multiple laser exposures, the acrylate continues to shrink; whereas (University of Dayton data) no additional shrinkage is observed in epoxy strands on a second hit. In force relaxation tests, a strand is drawn and then a 0.5% step strain is applied after different elapsed times. The epoxy initial modulus evolves (increases) with elapsed time following draw of the strand, and this evolution in modulus occurs after linear shrinkage has stopped. On the other hand, acrylates show no evolution of modulus with elapsed time following a single laser draw; i.e., once shrinkage stops after one laser hit, the initial modulus remains stable with elapsed time. Finally, relaxation response times of epoxy strands get larger with increasing elapsed time after laser draw. In acrylate strands there was no evolution in initial modulus with elapsed time after a single draw so relaxation times are not a function of elapsed time after a single hit with the laser.

  17. Effect of Beverages on the Hardness and Tensile Bond Strength of Temporary Acrylic Soft Liners to Acrylic Resin Denture Base

    PubMed Central

    Safari, A; Vojdani, M; Mogharrabi, S; Iraji Nasrabadi, N; Derafshi, R

    2013-01-01

    Statement of Problem: Two potential problems commonly identified with a denture base incorporating a resilient liner are failure of the bond between acrylic resin and soft liner material, and loss of resiliency of the soft liner over time. Since patients may drink different beverages, it is important to evaluate their effects on physical properties of soft lining materials. Purpose: The objective of this in vitro study was to evaluate the effect of different beverages on the hardness of two temporary acrylic-based soft lining materials and their bond strength to the denture base resin. Materials and Method: For the hardness test; a total of 80 rectangular specimens (40mm×10mm×3mm) were fabricated from a heat-polymerized polymethylmethacrylate. Two commercially auto-polymerized acrylic resin-based resilient liners; Coe-Soft and Visco-gel were prepared according to the manufacturers’ instructions and applied on the specimens. For the tensile test, 160 cylindrical specimens (30mm×10mm) were prepared. The liners were added between specimens with a thickness of 3 mm. The specimens of both soft liners were divided into 4 groups (n=10) and immersed in distilled water as the control group, Coca-Cola, 8% and 50% ethanol. All groups were stored in separate containers at 37oC for 12 days. All beverages were changed daily. The hardness was determined using a Shore A durometer and tensile bond strength was determined in a ZwickRoell testing machine at a cross-head speed of 5mm/min. The results were analyzed using two-way ANOVA. Results: There was no significant interaction between the soft liners and the drinks for both hardness (p= 0.748) and bond strength (p= 0.902). There were statistically significant differences between all drinks for both hardness (p< 0.001) and bond strength (p< 0.05). Conclusion: Within the limitations of this study, it seems that drinking Coca-Cola and alcoholic beverages would not be potentially causing any problems for the temporary

  18. Effect of different chemical disinfectants on the flexural strength of heat-polymerized acrylic resins.

    PubMed

    Savabi, O; Attar, K; Nejatidanesh, F; Goroohi, H; Badrian, H

    2013-09-01

    The purpose of this study was to evaluate the effect of chemical disinfectants on flexural strength of denture base acrylic resins. A total of 176 rectangular specimens (65x10x3 mm) were made from four heat-polymerized acrylic resins (Triplex,QC-20, Meliodent and Acropars) (n=44). The specimens were thermal cycled for 5000 cycles 5-55 degrees C and randomly divided into four groups (n=11). The specimens were immersed in 1% sodium hypochlorite, 2% glutaraldehyde, 10% Micro 10 or water for 30 minutes. The flexural strength was evaluated using a universal testing machine at a crosshead speed of 5 mm/min. Data were subjected to 2-way ANOVA and Tukey HSD (alpha=0.05). The highest flexural strengths of denture base resins were achieved after immersion in water (Triplex=128.9+/-12.8, QC-20=125+/-11.8, Meliodent=96.2+/-11.4 and Acropars=78.1+/-12.3 MPa). Triplex and QC-20 showed the highest flexural strengths in all of the solutions (P<0.05). The flexural strength of denture base acrylic resins was significantly affected by immersion in disinfection solutions but the reduction in flexural strengths of Triplex, QC-20 and Meliodent after disinfection by %1 sodium hypochlorite, %2 glutaraldhyde and Micro 10 were clinically insignificant.

  19. Effect of different solutions on color stability of acrylic resin-based dentures.

    PubMed

    Goiato, Marcelo Coelho; Nóbrega, Adhara Smith; dos Santos, Daniela Micheline; Andreotti, Agda Marobo; Moreno, Amália

    2014-01-01

    The aim of this study was to evaluate the effect of thermocycling and immersion in mouthwash or beverage solutions on the color stability of four different acrylic resin-based dentures (Onda Cryl, OC; QC20, QC; Classico, CL; and Lucitone, LU). The factors evaluated were type of acrylic resin, immersion time, and solution (mouthwash or beverage). A total of 224 denture samples were fabricated. For each type of resin, eight samples were immersed in mouthwashes (Plax-Colgate, PC; Listerine, LI; and Oral-B, OB), beverages (coffee, CP; cola, C; and wine, W), and artificial saliva (AS; control). The color change (DE) was evaluated before (baseline) and after thermocycling (T1), and after immersion in solution for 1 h (T2), 3 h (T3), 24 h (T4), 48 h (T5), and 96 h (T6). The CIE Lab system was used to determine the color changes. The thermocycling test was performed for 5000 cycles. Data were submitted to three-way repeated-measures analysis of variance and Tukey's test (p<0.05). When the samples were immersed in each mouthwash, all assessed factors, associated or not, significantly influenced the color change values, except there was no association between the mouthwash and acrylic resin. Similarly, when the samples were immersed in each beverage, all studied factors influenced the color change values. In general, regardless of the solution, LU exhibited the greatest DE values in the period from T1 to T5; and QC presented the greatest DE values at T6. Thus, thermocycling and immersion in the various solutions influenced the color stability of acrylic resins and QC showed the greatest color alteration.

  20. Effect of fabrication process on the bond strength between silicone elastomer and acrylic resin for maxillofacial prosthesis.

    PubMed

    Hattori, Mariko; Sumita, Yuka I; Muthiah, Lovely; Iwasaki, Naohiko; Takahashi, Hidekazu; Aimaijiang, Yiliyaer; Yoshi, Shigen; Taniguchi, Hisashi

    2014-01-01

    This study evaluated the effects of the fabrication process on tensile bond strength between maxillofacial silicone elastomer and acrylic resin. A common maxillofacial silicone elastomer (VST-50), two primers (Sofreliner primer and R-SI-LINE Plasticbond), and two acrylic resins (Unifast III and Palapress Vario) were selected. Silicone elastomer between primed acrylic resin plates were polymerized using a metal flask mold or a flaskless stone mold. Bond strength of the specimens was measured by a tensile test and analyzed using two-way analysis of variance (ANOVA) with Tukey's honest significant difference test. All fracture surfaces showed interfacial fracture. Both the fabrication process and the primer-acrylic resin combination affected bond strength, and two-way ANOVA indicated a significant interaction. Bond strength was generally greater when silicone elastomer was polymerized using a flaskless stone mold.

  1. Effect of tea, coffee and turmeric solutions on the colour of denture base acrylic resin: an in vitro study.

    PubMed

    Singh, S V; Aggarwal, Priyanki

    2012-09-01

    Discoloration of acrylic resin denture base when it comes in contact with various food materials and beverages in the oral cavity may cause aesthetic concern to a denture wearer. The objective of this study was to evaluate the effect of tea, coffee and turmeric solutions on the colour of different brands of heat cure acrylic resin denture base materials commonly used in India. Spectrophotometer was used to evaluate the colour change. A significant difference was found when change in colour was statistically analysed.

  2. Differential scanning calorimetric study of acrylic resin powders used in dentistry.

    PubMed

    Ohyama, A; Imai, Y

    2000-12-01

    The thermal behavior of eight dental acrylic resin powders was studied using differential scanning calorimetry (DSC). In addition, high performance liquid chromatography was performed to supplement the DSC analysis. The HPLC analysis revealed that the contents of residual monomers and benzoyl peroxide (BPO) in the powders were 0.01-0.97 mass% and 0.25-1.28 mass%, respectively. All the resin powders produced one broad exothermic peak, while a mixture of BPO and PMMA powders generated two peaks. One peak pattern was assigned to the decomposition of BPO included within the polymer particles. The results suggested that BPO was present inside the particles and little BPO was mixed into the resin powders. Moreover, the present study demonstrated a unique useability of DSC in characterizing resin powders.

  3. Flexural Strength of Acrylic Resin Denture Bases Processed by Two Different Methods

    PubMed Central

    Gharechahi, Jafar; Asadzadeh, Nafiseh; Shahabian, Foad; Gharechahi, Maryam

    2014-01-01

    Background and aims. The aim of this study was to compare flexural strength of specimens processed by conventional and injection-molding techniques. Materials and methods. Conventional pressure-packed PMMA was used for conventional pressure-packed and injection-molded PMMA was used for injection-molding techniques. After processing, 15 specimens were stored in distilled water at room temperature until measured. Three-point flexural strength test was carried out. Statistical analysis was carried out by SPSS using t-test. Statistical significance was defined at P<0.05. Results. Flexural strength of injection-polymerized acrylic resin specimens was higher than that of the conventional method (P=0.006). This difference was statistically significant (P=0.006). Conclusion. Within the limitations of this study, flexural strength of acrylic resin specimens was influenced by the molding technique. PMID:25346833

  4. Flexural strength of acrylic resin denture bases processed by two different methods.

    PubMed

    Gharechahi, Jafar; Asadzadeh, Nafiseh; Shahabian, Foad; Gharechahi, Maryam

    2014-01-01

    Background and aims. The aim of this study was to compare flexural strength of specimens processed by conventional and injection-molding techniques. Materials and methods. Conventional pressure-packed PMMA was used for conventional pressure-packed and injection-molded PMMA was used for injection-molding techniques. After processing, 15 specimens were stored in distilled water at room temperature until measured. Three-point flexural strength test was carried out. Statistical analysis was carried out by SPSS using t-test. Statistical significance was defined at P<0.05. Results. Flexural strength of injection-polymerized acrylic resin specimens was higher than that of the conventional method (P=0.006). This difference was statistically significant (P=0.006). Conclusion. Within the limitations of this study, flexural strength of acrylic resin specimens was influenced by the molding technique.

  5. Flexural strength of acrylic resin denture bases processed by two different methods.

    PubMed

    Gharechahi, Jafar; Asadzadeh, Nafiseh; Shahabian, Foad; Gharechahi, Maryam

    2014-01-01

    Background and aims. The aim of this study was to compare flexural strength of specimens processed by conventional and injection-molding techniques. Materials and methods. Conventional pressure-packed PMMA was used for conventional pressure-packed and injection-molded PMMA was used for injection-molding techniques. After processing, 15 specimens were stored in distilled water at room temperature until measured. Three-point flexural strength test was carried out. Statistical analysis was carried out by SPSS using t-test. Statistical significance was defined at P<0.05. Results. Flexural strength of injection-polymerized acrylic resin specimens was higher than that of the conventional method (P=0.006). This difference was statistically significant (P=0.006). Conclusion. Within the limitations of this study, flexural strength of acrylic resin specimens was influenced by the molding technique. PMID:25346833

  6. Time-related surface modification of denture base acrylic resin treated by atmospheric pressure cold plasma.

    PubMed

    Qian, Kun; Pan, Hong; Li, Yinglong; Wang, Guomin; Zhang, Jue; Pan, Jie

    2016-01-01

    The changes of denture base acrylic resin surface properties under cold plasma and the relationships with time were investigated. Cold plasma treated the specimens for 30 s, 60 s, 90 s, and 120 s, respectively. Water contact angles were measured immediately after the treatment, 48 h, 15 days and 30 days later. Surface roughness was measured with 3-D laser scanning microscope. Candida albicans adherence was evaluated by CFU counting. Chemical composition was monitored by X-ray photoelectron spectroscopy analysis. Water contact angle reduced after treated for 30 s. No changes were observed with time prolonged, except the durability. There were no differences in roughness among all groups. However, treatment groups showed significantly lower C. albicans adherence. XPS demonstrated a decrease in C/O, and this reduction was affected by treatment time. Cold plasma was an effective means of increasing hydrophilicity of acrylic resin and reducing C. albicans adherence without affecting physical properties.

  7. Using silicone impression material and acrylic resin to fabricate remount casts for removable partial dentures.

    PubMed

    Hsu, Yung-tsung; Farmer, John B

    2005-06-01

    A technique is described for fabrication of a remount cast for a removable partial denture. This procedure consists of filling the occlusal/incisal third with acrylic resin and injecting polyvinylsiloxane impression material into the irreversible hydrocolloid impression. This technique provides a simple method for making a remount cast and enables the clinician to remove and easily place the partial denture on the cast during occlusal refinement procedures without damage to the removable partial denture or the remount cast.

  8. Fabrication of a fixed provisional restoration utilizing a light-curing acrylic resin.

    PubMed

    Trushkowsky, R D

    1992-06-01

    The properly fabricated provisional restoration must take into account the following interrelated factors: pulpal protection, periodontal health, occlusion, esthetics, and phonetics. The techniques advocated for construction of a provisional restoration include direct, indirect, and a combination of direct and indirect techniques. Two simple techniques that use light-curing acrylic resin for the fabrication of fixed provisional restorations are presented, and advantages and disadvantages of these techniques are discussed.

  9. An evaluation of the cure of acrylic resin by three methods.

    PubMed

    Gay, W D; King, G E

    1979-10-01

    An investigation was designed and carried out to compare methyl acrylic resin processed by three methods--boiling, in the heat platen press, and a 9 hour, 75 degrees C cure. The material was cured in certain thicknesses in the heat platen press and by boiling without porosity. All samples cured for 9 hours at 75 degrees C had no porosity. The value of the heat platen press as a time-saving device and its applications in a maxillofacial laboratory were discussed.

  10. Effect of sodium bicarbonate on Candida albicans adherence to thermally activated acrylic resin.

    PubMed

    Sousa, Fernando Augusto Cervantes Garcia de; Paradella, Thaís Cachuté; Koga-Ito, Cristiane Yumi; Jorge, Antonio Olavo Cardoso

    2009-01-01

    The purpose of this study was to evaluate the effect of 5% sodium bicarbonate on the adherence of Candida albicans to thermally activated acrylic resin. Fifty 4 mm(2) specimens of acrylic resin were obtained using a metallic matrix. The specimens received chemical polishing, were sterilized and then immersed in Sabouraud broth, inoculated with Candida albicans standardized suspension. After 24 hours of incubation at 37 degrees Celsius, the specimens were divided into four groups according to the substance used for disinfection (5% sodium bicarbonate, 0.12% digluconate chlorhexidine, vinegar and Corega Tabs). A control group was included, in which distilled water was used. The adhered microorganisms were dispersed, diluted and plated onto culture media to determine the number of colony-forming units (cfu/mL). The results were analyzed through the Mann-Whitney statistical test at the 5% level of significance. Only 0.12% digluconate chlorhexidine and 5% sodium bicarbonate presented a statistically significant difference (p = 0.0010 and p = 0.0156, respectively) compared to the control group, decreasing the number of cfu/mL. However, when the different disinfecting solutions were compared with each other, only 0.12% digluconate chlorhexidine presented a statistically significant difference in the reduction of cfu/mL. It was concluded that although 0.12% digluconate chlorhexidine was more effective in the reduction of Candida albicans adherence values to thermally activated acrylic resin, 5% sodium bicarbonate also proved to be a viable alternative. PMID:20027444

  11. Effect of deep-freezing on some properties of acrylic resin.

    PubMed

    Isik, Gul; Harrison, Alan

    2005-06-01

    The objective of this study was to evaluate the effect of freezing the acrylic resin polymer/monomer dough mix on a range of properties of the polymerized denture base material. Powder and liquid of acrylic resin were mixed and at the dough stage transferred to a deep freezer and frozen for periods of 24 h, 1 week, 1 month, 3 months, and 6 months. At the end of the storage time, sufficient dough was removed, thawed, packed, and polymerized, and specimens were prepared from the polymerized plates. A control series was prepared from dough which had followed conventional mixing and packing procedures without freezing. The strength properties, hardness, and flash thickness were examined. Statistical analysis was carried out using ANOVA (one-way and two-way) with multiple range tests. The flexural strength was significantly (p=0.03) increased and the impact strength, hardness, and flash thickness were not affected by freezing the material during the dough stage. The flexural modulus was significantly (p=0.0001) reduced when the storage time in the freezer was increased to 3 months. Six months' frozen material proved to be unpackable. It was concluded that the acrylic resin polymer/monomer dough mix can be stored in the freezer for up to 1 month without any statistically significant effect on the properties of the polymerized denture base material. PMID:16191909

  12. Effect of deep-freezing on some properties of acrylic resin.

    PubMed

    Isik, Gul; Harrison, Alan

    2005-06-01

    The objective of this study was to evaluate the effect of freezing the acrylic resin polymer/monomer dough mix on a range of properties of the polymerized denture base material. Powder and liquid of acrylic resin were mixed and at the dough stage transferred to a deep freezer and frozen for periods of 24 h, 1 week, 1 month, 3 months, and 6 months. At the end of the storage time, sufficient dough was removed, thawed, packed, and polymerized, and specimens were prepared from the polymerized plates. A control series was prepared from dough which had followed conventional mixing and packing procedures without freezing. The strength properties, hardness, and flash thickness were examined. Statistical analysis was carried out using ANOVA (one-way and two-way) with multiple range tests. The flexural strength was significantly (p=0.03) increased and the impact strength, hardness, and flash thickness were not affected by freezing the material during the dough stage. The flexural modulus was significantly (p=0.0001) reduced when the storage time in the freezer was increased to 3 months. Six months' frozen material proved to be unpackable. It was concluded that the acrylic resin polymer/monomer dough mix can be stored in the freezer for up to 1 month without any statistically significant effect on the properties of the polymerized denture base material.

  13. Dimensional Changes of Acrylic Resin Denture Bases: Conventional Versus Injection-Molding Technique

    PubMed Central

    Gharechahi, Jafar; Asadzadeh, Nafiseh; Shahabian, Foad; Gharechahi, Maryam

    2014-01-01

    Objective: Acrylic resin denture bases undergo dimensional changes during polymerization. Injection molding techniques are reported to reduce these changes and thereby improve physical properties of denture bases. The aim of this study was to compare dimensional changes of specimens processed by conventional and injection-molding techniques. Materials and Methods: SR-Ivocap Triplex Hot resin was used for conventional pressure-packed and SR-Ivocap High Impact was used for injection-molding techniques. After processing, all the specimens were stored in distilled water at room temperature until measured. For dimensional accuracy evaluation, measurements were recorded at 24-hour, 48-hour and 12-day intervals using a digital caliper with an accuracy of 0.01 mm. Statistical analysis was carried out by SPSS (SPSS Inc., Chicago, IL, USA) using t-test and repeated-measures ANOVA. Statistical significance was defined at P<0.05. Results: After each water storage period, the acrylic specimens produced by injection exhibited less dimensional changes compared to those produced by the conventional technique. Curing shrinkage was compensated by water sorption with an increase in water storage time decreasing dimensional changes. Conclusion: Within the limitations of this study, dimensional changes of acrylic resin specimens were influenced by the molding technique used and SR-Ivocap injection procedure exhibited higher dimensional accuracy compared to conventional molding. PMID:25584050

  14. Synthesis and molecular characterization of acrylate liquid crystalline resin monomers (ALCRM).

    PubMed

    He, X P; Cai, W; Guo, L; Zhou, L Z; Nie, M H

    2015-01-01

    A novel biocompatible resin monomer 4—3—(acryloyloxy)—2—hydroxypropoxy) phenyl 4—(3—(acryloyloxy)—2—hydroxypropoxy) benzoate, as an oral restorative — acrylate liquid crystalline resin monomer (ALCRM) was synthesized. The intermediate product and the final product were characterized by differential scanning calorimetry (DSC), polarized optical microscope (POM), and nuclear magnetic resonance (NMR). A resin matrix which has a potential application in dental composites was prepared by photopolymerizing ALCRM and triethylene glycol dimethacrylate (TEGDMA) as a primary and diluted monomer with a photosensitizer of camphorquinone (CQ) and 2—(Dimethylamino)ethyl methacrylate (DMAEMA) mixture. The molar ratio of ALCRM and TEGDMA was 7:3. The properties such as the curing depth, curing time, and the volumetric shrinkage of the resin matrix were investigated and compared with a traditional composite resin matrix Bis—GMA. After photocuring polymerization, the conversion degree of the resin matrix is 68.06%, higher than Bis—GMA/TEGDMA; the curing time is 4.08±0.20min, the curing depth is 2.10±0.17mm, and the volumetric shrinkage is 3.62%±0.26%. All the properties exhibit a better performance of the prepared resin matrix than Bis—GMA. PMID:26475389

  15. Effect of TiO2 Nanoparticles on Tensile Strength of Dental Acrylic Resins.

    PubMed

    Shirkavand, Saeed; Moslehifard, Elnaz

    2014-01-01

    Background and aims. Adding further fillers to dental resins may enhance their physical characteristics. The aim of this study was to evaluate the tensile strength of heat-curing acrylic resin reinforced by TiO2nanoparticles added into the resin matrix. Materials and methods. Commercially available TiO2 nanoparticles were obtained and characterized using X-ray diffrac-tion (XRD) and scanning electron microscopy (SEM) to determine their crystalline structure, particle size and morphology. TiO2-acrylic resin nanocomposite was prepared by mixing 0.5, 1 and 2 (wt%) of surface modified TiO2 nanoparticles in an amalgamator providing three groups of samples. Before curing, the obtained paste was packed into steel molds. After cur-ing, the specimens were removed from the molds. The tensile strength test samples were prepared according to ISO 1567. Results. Two crystalline phases were found in TiO2 nanoparticles including: (i) anatase as the major one, and (ii) rutile. The average particle size calculated according to the Scherrer equation was 20.4 nm, showing a normal size distribution. According to SEM images, the nanocomposite with 1wt% TiO2 nanoparticles had a better distribution compared to other groups. In addition, the group by 1wt% TiO2 exhibited higher tensile strength with a significant difference compared to other groups. ANOVA showed significant differences between the contents of TiO2 particles in acrylic resin (F = 22.19; P < 0.001). Conclusion. A considerable increase in tensile strength was observed with titania NPs reinforcement agents in 1wt% by weight. Further increase of TiO2 nanoparticles decreased the tensile strength.

  16. Water Sorption and Flexural Strength of Thermoplastic and Conventional Heat-Polymerized Acrylic Resins

    PubMed Central

    Hemmati, Mohammad Ali; Vafaee, Fariborz

    2015-01-01

    Objectives: The aim of this study was to assess and compare the water sorption and flexural strength of thermoplastic and conventional acrylic resins. Materials and Methods: Water sorption and flexural strength were compared between a thermoplastic modified polymethyl methacrylate (PMMA) denture base resin (group A) and a heat-polymerized PMMA acrylic resin (group B) as the control group (n=10). A three-point bending test was carried out for flexural strength testing. For water sorption test, 10 disc-shaped samples were prepared. After desiccating, the samples were weighed and immersed in distilled water for seven days. Then, they were weighed again, and desiccated for the second and third times. Differences between the mean values in the two groups were analyzed using Student’s t-test. Results: The mean value of water sorption was 14.74±1.36 μg/mm3 in group A, and 19.11±0.90 μg/mm3 in group B; this difference was statistically significant (P< 0.001). The mean value of flexural strength was 88.21±8.63 MPa in group A and 77.77±9.49 MPa in group B. A significant difference was observed between the two groups (P= 0.019). Conclusion: Flexural strength of group A was significantly higher than that of group B, and its water sorption was significantly lower. Thus, thermoplastic resins can be a suitable alternative to conventional PMMA acrylic resins as denture base materials. PMID:26877737

  17. Effect of TiO2 Nanoparticles on Tensile Strength of Dental Acrylic Resins

    PubMed Central

    Shirkavand, Saeed; Moslehifard, Elnaz

    2014-01-01

    Background and aims. Adding further fillers to dental resins may enhance their physical characteristics. The aim of this study was to evaluate the tensile strength of heat-curing acrylic resin reinforced by TiO2nanoparticles added into the resin matrix. Materials and methods. Commercially available TiO2 nanoparticles were obtained and characterized using X-ray diffrac-tion (XRD) and scanning electron microscopy (SEM) to determine their crystalline structure, particle size and morphology. TiO2-acrylic resin nanocomposite was prepared by mixing 0.5, 1 and 2 (wt%) of surface modified TiO2 nanoparticles in an amalgamator providing three groups of samples. Before curing, the obtained paste was packed into steel molds. After cur-ing, the specimens were removed from the molds. The tensile strength test samples were prepared according to ISO 1567. Results. Two crystalline phases were found in TiO2 nanoparticles including: (i) anatase as the major one, and (ii) rutile. The average particle size calculated according to the Scherrer equation was 20.4 nm, showing a normal size distribution. According to SEM images, the nanocomposite with 1wt% TiO2 nanoparticles had a better distribution compared to other groups. In addition, the group by 1wt% TiO2 exhibited higher tensile strength with a significant difference compared to other groups. ANOVA showed significant differences between the contents of TiO2 particles in acrylic resin (F = 22.19; P < 0.001). Conclusion. A considerable increase in tensile strength was observed with titania NPs reinforcement agents in 1wt% by weight. Further increase of TiO2 nanoparticles decreased the tensile strength. PMID:25587380

  18. Effect of water-aging on the antimicrobial activities of an ORMOSIL-containing orthodontic acrylic resin.

    PubMed

    Gong, Shi-Qiang; Epasinghe, D Jeevanie; Zhou, Bin; Niu, Li-Na; Kimmerling, Kirk A; Rueggeberg, Frederick A; Yiu, Cynthia K Y; Mao, Jing; Pashley, David H; Tay, Franklin R

    2013-06-01

    Quaternary ammonium methacryloxy silicate (QAMS), an organically modified silicate (ORMOSIL) functionalized with polymerizable methacrylate groups and an antimicrobial agent with a long lipophilic alkyl chain quaternary ammonium group, was synthesized through a silane-based sol-gel route. By dissolving QAMS in methyl methacrylate monomer, this ORMOSIL molecule was incorporated into an auto-polymerizing, powder/liquid orthodontic acrylic resin system, yielding QAMS-containing poly(methyl methacrylate). The QAMS-containing acrylic resin showed a predominant contact-killing effect on Streptococcus mutans (ATCC 35668) and Actinomyces naeslundii (ATCC 12104) biofilms, while inhibiting adhesion of Candida albicans (ATCC 90028) on the acrylic surface. The antimicrobial activities of QAMS-containing acrylic resin were maintained after a 3month water-aging period. Bromophenol blue assay showed minimal leaching of quaternary ammonium species when an appropriate amount of QAMS (<4wt.%) was incorporated into the acrylic resin. The results suggest that QAMS is predominantly co-polymerized with the poly(methyl methacrylate) network, and only a minuscule amount of free QAMS molecules is present within the polymer network after water-aging. Acrylic resin with persistent antimicrobial activities represents a promising method for preventing bacteria- and fungus-induced stomatitis, an infectious disease commonly associated with the wearing of removable orthodontic appliances.

  19. Effect of water-aging on the antimicrobial activities of an ORMOSIL-containing orthodontic acrylic resin

    PubMed Central

    Gong, Shi-qiang; Epasinghe, D. Jeevanie; Zhou, Bin; Niu, Li-na; Kimmerling, Kirk A.; Rueggeberg, Frederick A.; Yiu, Cynthia K.Y.; Mao, Jing; Pashley, David H.; Tay, Franklin R.

    2013-01-01

    Quaternary ammonium methacryloxy silicate (QAMS), an organically modified silicate (ORMOSIL) functionalized with polymerizable methacrylate groups and an antimicrobial agent with a long lipophilic alkyl chain quaternary ammonium group, was synthesized through a silane-based sol–gel route. By dissolving QAMS in methyl methacrylate monomer, this ORMOSIL molecule was incorporated into an auto-polymerizing, powder/liquid orthodontic acrylic resin system, yielding QAMS-containing poly (methyl methacrylate). The QAMS-containing acrylic resin showed a predominant contact-killing effect on Streptococcus mutans (ATCC 35668) and Actinomyces naeslundii (ATCC 12104) biofilms, while inhibiting adhesion of Candida albicans (ATCC 90028) on the acrylic surface. The antimicrobial activities of QAMS-containing acrylic resin were maintained after a 3 month water-aging period. Bromophenol blue assay showed minimal leaching of quaternary ammonium species when an appropriate amount of QAMS (<4 wt.%) was incorporated into the acrylic resin. The results suggest that QAMS is predominantly co-polymerized with the poly(methyl methacrylate) network, and only a minuscule amount of free QAMS molecules is present within the polymer network after water-aging. Acrylic resin with persistent antimicrobial activities represents a promising method for preventing bacteria- and fungus-induced stomatitis, an infectious disease commonly associated with the wearing of removable orthodontic appliances. PMID:23485857

  20. Bonding of acrylic denture teeth to resin denture bases.

    PubMed

    Geerts, G A V M; Stuhlinger, M E

    2012-07-01

    Anterior teeth debonding from dentures is a common problem. This study tested the bond strength of denture teeth to two types of denture resin, with and without grooving the ridge-lap surface. Bond strength and fracture type of three different groups were compared: 1. Teeth bonded to heat-cured polymethyl methacrylate (PMMA); 2. Teeth bonded to pour-type PMMA; 3. Grooved teeth bonded to pour-type PMMA. Specimens were manufactured following ISO standard 22112. Force values at failure were analysed using one-way analysis of variance, using the mixed procedure with confidence interval of 95%. Types of failure were identified as adhesive, cohesive or combination. In descending order, mean failure forces were 418.55N (Group One), 367.55N (Group Two) and 290.05N (Group Three). There was no significant difference between the means of groups 1 and 2 (p = 0.0627). Group Three differed from both other groups (p < 0.001). Groups One and Two showed predominantly cohesive fractures wthin denture teeth (83% and 72% respectively); group Three showed predominantly cohesive fractures within the denture PMMA (75%). Without ridge-lap modification, the bond strengths of denture teeth to pour-type and heat-cured denture resin were similar. Failures were predominantly of cohesive nature within the teeth themselves. Grooving the ridge-lap reduced fracture resistance and led to breakages predominantly in denture PMMA.

  1. Antifungal Effect of Zataria multiflora Essence on Experimentally Contaminated Acryl Resin Plates With Candida albicans

    PubMed Central

    Jafari, Abbas Ali; Falah Tafti, Abbas; Hoseiny, Seyed Mehdi; Kazemi, Abdolhossein

    2015-01-01

    Background: Adherence and colonization of Candida species particularly C. albicans on denture surfaces, forms a microbial biofilm, which may result denture stomatitis in complete denture users. Objectives: The purpose of the present study was to evaluate the antifungal effect Zataria multiflora essence in removing of Candida albicans biofilms on experimentally contaminated resin acryl plates. Materials and Methods: In the present experimental study, 160 resin acrylic plates (10 × 10 × 1 mm) were contaminated by immersion in 1 × 103 C. albicans suspension for 24 hours to prepare experimental Candida biofilms. The total number of Candida cells, which adhered to 20 randomly selected acryl resin plates was determined as the Candia load before cleaning. The remaining 140 plates were divided to seven groups of 20 and immersed in five concentrations of Zataria multiflora essence from 50 to 3.125 mg/mL as test, 100000 IU nystatin as the positive and sterile physiologic serum as the negative control. The remaining Candida cells on each acryl plate were also enumerated and data were analyzed using the SPSS 16 software with Kruskal-Wallis and Wilcoxon tests. Results: Zataria essence at concentrations of 50 and 25 mg/mL removed 100% of attached Candida cells similar to nystatine (MFC), while weaker Zataria essence solutions cleaned 88%, 60.5% and 44.7% of attached Candida cells. Kruskal-wallis test showed a statistically significant difference between all test groups (P = 0.0001). In this study 12.5 mg/mL concentration of Zataria multiflora was considered as the minimum inhibitory concentration (MIC90). Conclusions: Zataria essence, at concentrations of 50 and 25 mg/mL, effectively removed Candida cells that had adhered to the denture surface, similar to the level of removal observed for 100000 IU nystatin. PMID:25763273

  2. The effect of powder/liquid mixing ratio on the stiffness and impact strength of autopolymerising dental acrylic resins.

    PubMed

    Syme, V J; Lamb, D J; Lopattananon, N; Ellis, B; Jones, F R

    2001-06-01

    The stiffness of representative cured autopolymerising dental acrylic resins was determined by calculation of a secant modulus from measurements in tension of load and extension, and related to the powder/liquid mixing ratio. The impact strengths of autopolymerising, heat-cure and commercial resins were compared. It was found that while the stiffness of autopolymerising resins was unaffected by variations in powder/liquid mixing ratio, extension to failure was greater with lower powder/liquid ratios. The impact strength of autopolymerising resins was found to be greater than that of heat-cure resins, and a tentative explanation is offered. These findings may help to explain the pattern of failure of acrylic resin denture bases.

  3. Effect of Polymerization Cycles on Gloss, Roughness, Hardness and Impact Strength of Acrylic Resins.

    PubMed

    Consani, Rafael Leonardo Xediek; Folli, Bianca L; Nogueira, Moises C F; Correr, Americo Bortolazzo; Mesquita, Marcelo F

    2016-01-01

    The aim of this study was to evaluate the conventional and boiled polymerization cycles on gloss, roughness, hardness and impact strength of acrylic resins. Samples were made for each Classico and QC-20 materials (n=10) in dental stone molds obtained from rectangular metallic matrices embedded in metallic flasks. The powder-liquid ratio and manipulation of the acrylic resins' were accomplished according to manufacturers' instructions and the resins were conventionally packed in metallic flasks. After polymerization by (1) conventional: 74 °C for 9 h (Classico) and (2) boiled: 20 min (QC-20) cycles, the samples were deflasked after cooling at room temperature and conventionally finished and polished. The properties were evaluated after storage in water at 37 °C for 24 h. Gloss was verified with Multi Gloss 268 meter (Konica Minolta), surface roughness was measured with Surfcorder SE 1700 rugosimeter (Kosaka), Knoop hardness number was obtained with HMV-200 microdurometer, and impact strength was measured in an Otto Wolpert-Werke device by Charpy system (40 kpcm). Data were subjected to Student's t-test (at α=0.05). The results were: Gloss: 67.7 and 62.2 for Classico and QC-20 resins, respectively; Surface roughness: 0.874 and 1.469 Ra-µm for Classico and QC-20, respectively; Knoop hardness: 27.4 and 26.9 for Classico and QC-20, respectively; and Impact strength: 37.6 and 33.6 kgf/cm2 for Classico and QC-20, respectively. No statistically significant difference (p>0.05)were found between the resins for the evaluated properties. In conclusion, conventional and boiled polymerization cycles had similar effects on gloss, roughness, hardness and impact strength of both Classico and QC-20 resins.

  4. Comparing the degree of exothermic polymerization in commonly used acrylic and provisional composite resins for intraoral appliances.

    PubMed

    Rice, C A; Riehl, Jessica; Broman, Karl; Soukup, Jason W; Gengler, William R

    2012-01-01

    The use of dental acrylics and composite resins in veterinary dentistry has become widespread. However their use is not without potential complications. All acrylics and composite resins produce an exothermic reaction during the polymerization process. The aim of the current study was to evaluate thermal conduction during the polymerization reaction of each material to offer clinical guidelines when choosing a material with particular consideration for the significant volumes typically used. Results showed that methylmethacrylate based resins generated a significantly higher degree of heat during polymerization. Bis-acryl based composite resins generated a significantly lower degree of heat during polymerization, making them the material of choice to potentially minimize thermal injury to the dentin-pulp complex. It is the responsibility of the clinician to become aware of all materials available, and to have an understanding of their properties to guide them in making sound clinical judgments.

  5. Rehabilitation of post-traumatic total nasal defect using silicone and acrylic resin.

    PubMed

    Aggarwal, Vikas; Datta, Kusum; Kaur, Sukhjit

    2016-01-01

    Facial defects resulting from neoplasms, congenital abnormalities or trauma can affect the patient esthetically, psychologically, and even financially. Surgical reconstruction of large facial defects is sometimes not possible and frequently demands prosthetic rehabilitation. For success of such prosthesis, adequate replication of natural anatomy, color matching and blending with tissue interface are important criteria. Variety of materials and retention methods are advocated to achieve a functionally and esthetically acceptable restoration. Silicones are the most commonly used materials because of flexibility, lifelike appearance and ability to be used in combination with acrylic resin which is hard, provides body and helps in achieving retention to the prosthesis by engaging mechanical undercuts. Furthermore, the acrylic portion can be relined easily, thus helping comfortable wear and removal of the prosthesis by patient without traumatizing nasal mucosa. This case report describes time saving and cost effective prosthetic rehabilitation of a patient with total nasal defect using custom sculpted nasal prosthesis made up of silicone elastomer and acrylic resin, which is retained by engaging mechanical undercut and use of biocompatible silicone adhesive.

  6. The effect of disinfectant solutions on the hardness of acrylic resin denture teeth.

    PubMed

    Pavarina, A C; Vergani, C E; Machado, A L; Giampaolo, E T; Teraoka, M T

    2003-07-01

    This investigation studied the effects of disinfectant solutions on the hardness of acrylic resin denture teeth. The occlusal surfaces of 64 resin denture teeth were ground flat with abrasives up to 400-grit silicon carbide paper. Measurements were made after polishing and after the specimens were stored in water at 37 degrees C for 48 h. The specimens were then divided into four groups and immersed in chemical disinfectants (4% chlorhexidine; 1% sodium hypochlorite and sodium perborate) for 10 min. The disinfection methods were performed twice to simulate clinical conditions and hardness measurements were made. Specimens tested as controls were immersed in water during the same disinfection time. Eight specimens were produced for each group. After desinfection procedures, testing of hardness was also performed after the samples were stored at 37 degrees C for 7, 30, 60, 90 and 120 days. Data were analysed using two-way analysis of variance (anova) and Tukey's test at 95% confidence level. According to the results, no significant differences were found between materials and immersion solutions (P > 0.05). However, a continuous decrease in hardness was noticed after ageing (P < 0.05). It was conclude that the surfaces of both acrylic resin denture teeth softened upon immersion in water regardless the disinfecting solution.

  7. The Influence of Polymerization Type and Reinforcement Method on Flexural Strength of Acrylic Resin

    PubMed Central

    Fonseca, Rodrigo Borges; Kasuya, Amanda Vessoni Barbosa; Favarão, Isabella Negro; Naves, Lucas Zago; Hoeppner, Márcio Grama

    2015-01-01

    The aim of this study was to evaluate the flexural strength of acrylic resin bars by varying the types of resin polymerization and reinforcement methods. Fourteen groups (N = 10) were created by the interaction of factors in study: type of resin (self-cured (SC) or heat-cured (HC)) and reinforcement method (industrialized glass fiber (Ind), unidirectional glass fiber (Uni), short glass fiber (Short), unidirectional and short glass fiber (Uni-Short), thermoplastic resin fiber (Tpl), and steel wire (SW)). Reinforced bars (25 × 2 × 2 mm) were tested in flexural strength (0.5 mm/min) and examined by scanning electron microscopy (SEM). Data (MPa) were submitted to factorial analysis, ANOVA, and Tukey and T-student tests (a = 5%) showing significant interaction (P = 0.008), for SC: Uni (241.71 ± 67.77)a, Uni-Short (221.05 ± 71.97)a, Ind (215.21 ± 46.59)ab, SW (190.51 ± 31.49)abc, Short (156.31 ± 28.76)bcd, Tpl (132.51 ± 20.21)cd, Control SC (101.47 ± 19.79)d and for HC: Ind (268.93 ± 105.65)a, Uni (215.14 ± 67.60)ab, Short (198.44 ± 95.27)abc, Uni-Short (189.56 ± 92.27)abc, Tpl (161.32 ± 62.51)cd, SW (106.69 ± 28.70)cd, and Control HC (93.39 ± 39.61)d. SEM analysis showed better fiber-resin interaction for HC. Nonimpregnated fibers, irrespective of their length, tend to improve fracture strength of acrylics. PMID:25879079

  8. The influence of polymerization type and reinforcement method on flexural strength of acrylic resin.

    PubMed

    Fonseca, Rodrigo Borges; Kasuya, Amanda Vessoni Barbosa; Favarão, Isabella Negro; Naves, Lucas Zago; Hoeppner, Márcio Grama

    2015-01-01

    The aim of this study was to evaluate the flexural strength of acrylic resin bars by varying the types of resin polymerization and reinforcement methods. Fourteen groups (N=10) were created by the interaction of factors in study: type of resin (self-cured (SC) or heat-cured (HC)) and reinforcement method (industrialized glass fiber (Ind), unidirectional glass fiber (Uni), short glass fiber (Short), unidirectional and short glass fiber (Uni-Short), thermoplastic resin fiber (Tpl), and steel wire (SW)). Reinforced bars (25×2×2 mm) were tested in flexural strength (0.5 mm/min) and examined by scanning electron microscopy (SEM). Data (MPa) were submitted to factorial analysis, ANOVA, and Tukey and T-student tests (a=5%) showing significant interaction (P=0.008), for SC: Uni (241.71±67.77)a, Uni-Short (221.05±71.97)a, Ind (215.21±46.59)ab, SW (190.51±31.49)abc, Short (156.31±28.76)bcd, Tpl (132.51±20.21)cd, Control SC (101.47±19.79)d and for HC: Ind (268.93±105.65)a, Uni (215.14±67.60)ab, Short (198.44±95.27)abc, Uni-Short (189.56±92.27)abc, Tpl (161.32±62.51)cd, SW (106.69±28.70)cd, and Control HC (93.39±39.61)d. SEM analysis showed better fiber-resin interaction for HC. Nonimpregnated fibers, irrespective of their length, tend to improve fracture strength of acrylics.

  9. Effect of an acrylic resin combined with an antimicrobial polymer on biofilm formation

    PubMed Central

    MARRA, Juliê; PALEARI, André Gustavo; RODRIGUEZ, Larissa Santana; LEITE, Andressa Rosa Perin; PERO, Ana Carolina; COMPAGNONI, Marco Antonio

    2012-01-01

    Objectives The purpose of this study was to evaluate the antimicrobial activity of an acrylic resin combined with an antimicrobial polymer poly (2-tert-butylaminoethyl) methacrylate (PTBAEMA) to inhibit Staphylococcus aureus, Streptococcus mutans and Candida albicans biofilm formation. Material and Methods Discs of a heat-polymerized acrylic resin were produced and divided according to PTBAEMA concentration: 0 (control), 10 and 25%. The specimens were inoculated (107 CFU/mL) and incubated at 37ºC for 48 h. After incubation, the wells were washed and each specimen was sonicated for 20 min. Replicate aliquots of resultant suspensions were plated at dilutions at 37ºC for 48 h. The number of colony-forming units (CFU) was counted and expressed as log (CFU+1)/mL and analyzed statistically with α=.05. Results The results showed that 25% PTBAEMA completely inhibited S. aureus and S. mutans biofilm formation. A significant reduction of log (CFU+1)/mL in count of S. aureus (control: 7.9±0.8A; 10%: 3.8±3.3B) and S. mutans (control: 7.5±0.7A; 10%: 5.1±2.7B) was observed for the group containing 10% PTBAEMA (Mann-Whitney, p<0.05). For C. albicans, differences were not significant among the groups (control: 6.6±0.2A; 10%: 6.6±0.4A; 25%: 6.4±0.1A), (Kruskal-Wallis, p>0.05, P=0.079). Conclusions Acrylic resin combined with 10 and 25% of PTBAEMA showed significant antimicrobial activity against S. aureus and S. mutans biofilm, but it was inactive against the C. albicans biofilm. PMID:23329246

  10. Flexural strength of acrylic resin repairs processed by different methods: water bath, microwave energy and chemical polymerization

    PubMed Central

    ARIOLI FILHO, João Neudenir; BUTIGNON, Luís Eduardo; PEREIRA, Rodrigo de Paula; LUCAS, Matheus Guilherme; MOLLO JUNIOR, Francisco de Assis

    2011-01-01

    Denture fractures are common in daily practice, causing inconvenience to the patient and to the dentists. Denture repairs should have adequate strength, dimensional stability and color match, and should be easily and quickly performed as well as relatively inexpensive. Objective The aim of this study was to evaluate the flexural strength of acrylic resin repairs processed by different methods: warm water-bath, microwave energy, and chemical polymerization. Material and methods Sixty rectangular specimens (31x10x2.5 mm) were made with warm water-bath acrylic resin (Lucitone 550) and grouped (15 specimens per group) according to the resin type used to make repair procedure: 1) specimens of warm water-bath resin (Lucitone 550) without repair (control group); 2) specimens of warm water-bath resin repaired with warm water-bath; 3) specimens of warm water-bath resin repaired with microwave resin (Acron MC); 4) specimens of warm water-bath resin repaired with autopolymerized acrylic resin (Simplex). Flexural strength was measured with the three-point bending in a universal testing machine (MTS 810 Material Test System) with load cell of 100 kgf under constant speed of 5 mm/min. Data were analyzed statistically by Kruskal-Wallis test (p<0.05). Results The control group showed the best result (156.04±1.82 MPa). Significant differences were found among repaired specimens and the results were decreasing as follows: group 3 (43.02±2.25 MPa), group 2 (36.21±1.20 MPa) and group 4 (6.74±0.85 MPa). Conclusion All repaired specimens demonstrated lower flexural strength than the control group. Repairs with autopolymerized acrylic resin showed the lowest flexural strength. PMID:21625742

  11. Bond strength of acrylic teeth to denture base resin after various surface conditioning methods before and after thermocycling.

    PubMed

    Saavedra, Guilherme; Valandro, Luiz Felipe; Leite, Fabiola Pessoa Pereira; Amaral, Regina; Ozcan, Mutlu; Bottino, Marco A; Kimpara, Estevão T

    2007-01-01

    This study aimed to evaluate the durability of adhesion between acrylic teeth and denture base acrylic resin. The base surfaces of 24 acrylic teeth were flatted and submitted to 4 surface treatment methods: SM1 (control): No SM; SM2: application of a methyl methacrylate-based bonding agent (Vitacol); SM3: air abrasion with 30-microm silicone oxide plus silane; SM4: SM3 plus SM2. A heat-polymerized acrylic resin was applied to the teeth. Thereafter, bar specimens were produced for the microtensile test at dry and thermocyled conditions (60 days water storage followed by 12,000 cycles). The results showed that bond strength was significantly affected by the SM (P < .0001) (SM4 = SM2 > SM3 > SM1) and storage regimens (P < .0001) (dry > thermocycled). The methyl methacrylate-based adhesive showed the highest bond strength. PMID:17455445

  12. Effects of Sonication Conditions on Ultrasonic Dispersion of Inorganic Particles in Acrylic Resin

    NASA Astrophysics Data System (ADS)

    Tuziuti, Toru; Yasui, Kyuichi; Towata, Atsuya; Kato, Kazumi

    2011-07-01

    The effects of sonication conditions on the ultrasonic dispersion of titanium dioxide particles in acrylic resin are investigated. Pulsing operation at appropriate on-off duty cycles enables us to attain a particle size smaller than that at a continuous wave (CW) at the same net time of sonication between operations. It is useful that frequency-sweep operation attains almost the same particle size as that at CW, which can provide a constant dispersion of particles even if the resonant frequency used to effectively drive an ultrasonic transducer changes with liquid conditions, such as the temperature and acoustic impedance of a liquid.

  13. The dimensional accuracy of rectangular acrylic resin specimens cured by three denture base processing methods.

    PubMed

    Salim, S; Sadamori, S; Hamada, T

    1992-06-01

    The dimensional accuracy of rectangular acrylic resin specimens was examined when they were processed by three methods: a conventional method, the SR-Ivocap system, and a microwave curing method. The dimensional accuracy was evaluated by the change of the distance vector V, which is calculated by means of measurements of the distances between fixed points on specimens. The specimen cured by the SR-Ivocap system exhibited less dimensional change (p less than 0.05) than those cured by the conventional and the microwave curing methods. The SR-Ivocap system might produce a more accurate denture base than the conventional and the microwave curing methods.

  14. Cold plasma-induced surface modification of heat-polymerized acrylic resin and prevention of early adherence of Candida albicans.

    PubMed

    Pan, Hong; Wang, Guomin; Pan, Jie; Ye, Guopin; Sun, Ke; Zhang, Jue; Wang, Jing

    2015-01-01

    Atmospheric-pressure cold plasma was applied to process the surface of heat-polymerized acrylic resin. Changes to the physical properties and early adherence of Candida albicans were investigated. Alternating current cold plasma with Ar/O2 as working gas was used. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were employed to study the possible mechanism. Experimental results showed that after plasma treatment, the contact angle of acrylic resin significantly decreased. There were no significant differences in roughness, flexural strength and elasticity modulus, but microhardness was significant improved in the treated group. More importantly, the early adherence of Candida albicans on the surface was reduced after plasma treatment. Cold plasma seemed to be a promising and convenient strategy of preventing the early adherence of Candida albicans on acrylic resins, which would greatly benefit potential dental applications.

  15. A technique to splint and verify the accuracy of implant impression copings with light-polymerizing acrylic resin.

    PubMed

    Rutkunas, Vygandas; Ignatovic, Jevgenija

    2014-03-01

    Transferring the implant position from the mouth to the definitive cast is one of the most critical steps in implant prosthodontics. To achieve a passive fit of the prosthesis, an accurate implant impression is crucial because discrepancies can induce both biologic and technical complications. Analysis of available research data suggests that a direct (pick-up) impression technique with splinted copings is the technique of choice, particularly for multiple implants. However, the traditional method of splinting the copings with autopolymerizing acrylic resin is a technique-sensitive and time- consuming procedure. This report describes a straightforward method of splinting impression copings with light-polymerizing acrylic resin, with minimal amount of autopolymerizing acrylic resin. The method also can be used to verify splinting accuracy.

  16. Allergic effects of the residual monomer used in denture base acrylic resins

    PubMed Central

    Rashid, Haroon; Sheikh, Zeeshan; Vohra, Fahim

    2015-01-01

    Denture base resins are extensively used in dentistry for a variety of purposes. These materials can be classified as chemical, heat, light, and microwave polymerization materials depending upon the factor which starts the polymerization reaction. Their applications include use during denture base construction, relining existing dentures, and for fabrication of orthodontic removable appliances. There have been increased concerns regarding the safe clinical application of these materials as their biodegradation in the oral environment leads to harmful effects. Along with local side effects, the materials have certain occupational hazards, and numerous studies can be found in the literature mentioning those. The purpose of this article is to outline the cytotoxic consequences of denture base acrylic resins and clinical recommendations for their use. PMID:26929705

  17. Allergic effects of the residual monomer used in denture base acrylic resins.

    PubMed

    Rashid, Haroon; Sheikh, Zeeshan; Vohra, Fahim

    2015-01-01

    Denture base resins are extensively used in dentistry for a variety of purposes. These materials can be classified as chemical, heat, light, and microwave polymerization materials depending upon the factor which starts the polymerization reaction. Their applications include use during denture base construction, relining existing dentures, and for fabrication of orthodontic removable appliances. There have been increased concerns regarding the safe clinical application of these materials as their biodegradation in the oral environment leads to harmful effects. Along with local side effects, the materials have certain occupational hazards, and numerous studies can be found in the literature mentioning those. The purpose of this article is to outline the cytotoxic consequences of denture base acrylic resins and clinical recommendations for their use.

  18. COLOR STABILITY OF DENTURE TEETH AND ACRYLIC BASE RESIN SUBJECTED DAILY TO VARIOUS CONSUMER CLEANSERS

    PubMed Central

    Moon, Audrey; Powers, John M.; Kiat-amnuay, Sudarat

    2014-01-01

    Objective This study evaluated color stability of acrylic denture teeth and base resins after 48 weeks of commercial denture cleanser simulation. Materials and Methods Two brands of denture teeth (Trubyte Portrait IPN, TP; SR Vivodent DCL, SR) in shades A1, B1, and C1 and three acrylic base resins (Lucitone, LU; Paragon, PA; Valplast, VA) prepared to manufacturer’s specifications, were exposed 10 hours daily to four cleansers (Clorox Bleach, CB; Polident 3-minute, PO3; Efferdent, EF; and Kleenite, KL) and distilled water (DW) control, approximating consumer overnight use. Color measurements used the CIE L*a*b* color space (0, 4, 12, 24, 36, and 48 weeks.) Color differences (ΔE*) at 48-weeks were subjected to 4-way analysis-of-variance (ANOVA). Mean values were compared with Fisher’s PLSD intervals (0.05 significance level). Results Mean color differences (ΔE*) demonstrated color changes in each material. ANOVA indicated color changes in teeth were significantly affected by both cleansers and teeth brand (p<0.05), but not shade. Color changes in base resins were significantly affected by cleansers (p<0.05), but not brand alone. Overall, KL produced the least color change while CB and PO3 produced the most for all materials. Conclusions After 48 weeks of daily simulation, TP teeth were more color-stable than SR in all cleansers except EF (p<0.0001). Base resin VA was less color-stable than LU and PA. Cleanser KL resulted in the lowest color changes. Clinical Significance All tested materials yield clinically acceptable color changes (ΔE*<3.5); all cleansing methods tested can be recommended, though Kleenite demonstrated the least change after 48-weeks. PMID:24980803

  19. Effect of long-term water immersion or thermal shock on mechanical properties of high-impact acrylic denture base resins.

    PubMed

    Sasaki, Hirono; Hamanaka, Ippei; Takahashi, Yutaka; Kawaguchi, Tomohiro

    2016-01-01

    The purpose of this study was to investigate the effect of long-term water immersion or thermal shock on the mechanical properties of high-impact acrylic denture base resins. Two high-impact acrylic denture base resins were selected for the study. Specimens of each denture base material tested were fabricated according to the manufacturers' instructions (n=10). The flexural strength at the proportional limit, the elastic modulus and the impact strength of the specimens were evaluated. The flexural strength at the proportional limit of the high-impact acrylic denture base resins did not change after six months' water immersion or thermocycling 50,000 times. The elastic moduli of the high-impact acrylic denture base resins significantly increased after six months' water immersion or thermocycling 50,000 times. The impact strengths of the high-impact acrylic denture base resins significantly decreased after water immersion or thermocycling as described above.

  20. Bond of acrylic teeth to different denture base resins after various surface-conditioning methods.

    PubMed

    Lang, Reinhold; Kolbeck, Carola; Bergmann, Rainer; Handel, Gerhard; Rosentritt, Martin

    2012-02-01

    The study examined the bond between different denture base resins and highly cross-linked acrylic denture teeth with different base surface-conditioning methods. One hundred fifty highly cross-linked resin denture teeth (SR-Antaris, No. 11, Ivoclar-Vivadent, FL) were divided into five groups with different surface-conditioning methods of the base surfaces of the teeth (C = control, no surface conditioning, MM = application of methyl methacrylate monomer, SB = sand blasting, SBB = sand blasting + bonding agent, TSS = tribochemical silica coating + silanization). Teeth were bonded to either a cold-cured denture base resin (ProBase Cold, Ivoclar-Vivadent, FL) or heat-cured denture base resins (SR Ivocap Plus, Ivoclar-Vivadent, FL and Lucitone 199, Dentsply, USA). After 24 h of storage in distilled water, compressive load was applied at 90° on the palatal surface of each tooth until fracture. Median failure load ranged between 103 and 257 N for Probase Cold groups, 91 to 261 N for Lucitone 199, and 149 to 320 N for SR Ivocap Plus. For Probase Cold, significant highest failure loads resulted when teeth were treated with SB, SBB, or TSS. For Lucitone 199, significant highest failure loads has been found with MM and TSS treatment. For SR Ivocap Plus, highest failure loads resulted using SBB and TSS. Conditioning of the base surfaces of the teeth prior to denture base processing is highly recommended. Tooth bond is significantly affected by the surface-conditioning method and applied denture base resin. Tribochemical silica coating + silanization method can be recommended for pre-treatment of teeth applying either heat-cured or cold-cured denture base resin.

  1. Toxicity analysis of ocular prosthesis acrylic resin with or without pigment incorporation in human conjunctival cell line.

    PubMed

    da Silva, Emily Vivianne Freitas; Goiato, Marcelo Coelho; Bonatto, Liliane da Rocha; de Medeiros, Rodrigo Antonio; Santos, Daniela Micheline Dos; Rangel, Elidiane Cipriano; Oliveira, Sandra Helena Penha de

    2016-10-01

    The aim of this study was to evaluate the influence of pigment incorporation on the cytotoxicity of ocular prosthesis N1 color acrylic resin. Nine samples were manufactured by heat-polymerization in water bath and divided into 3 groups: acrylic resin without pigment incorporation (group R), acrylic resin with pigment incorporation (group RP), and acrylic pigment (group P). Eluates formed after 72h of sample immersion in medium were incubated with conjunctival cell line (Chang conjunctival cells) for 72h. The negative control group consisted in medium without samples (group C). The cytotoxic effect from the eluates was evaluated using MTT assay (cell proliferation), ELISA assay (quantification of IL1β, IL6, TNF α and CCL3/MIP1α) and RT-PCR assay (mRNA expression of COL IV, TGF β and MMP9). Data were submitted to ANOVA with Bonferroni post-tests (p<0.05). All groups were considered non-cytotoxic based on cell proliferation. However, resin with pigment incorporation showed significant IL6 quantity increase. Resin without pigment incorporation exhibited higher mRNA expression of COL IV, MMP9 and TGF β, however it was also observed for the negative control group. The materials exhibited divergent biological behavior. Despite the pigment incorporation that resulted in an increase of IL6, no cytotoxicity was observed based on cell proliferation. PMID:27521695

  2. Toxicity analysis of ocular prosthesis acrylic resin with or without pigment incorporation in human conjunctival cell line.

    PubMed

    da Silva, Emily Vivianne Freitas; Goiato, Marcelo Coelho; Bonatto, Liliane da Rocha; de Medeiros, Rodrigo Antonio; Santos, Daniela Micheline Dos; Rangel, Elidiane Cipriano; Oliveira, Sandra Helena Penha de

    2016-10-01

    The aim of this study was to evaluate the influence of pigment incorporation on the cytotoxicity of ocular prosthesis N1 color acrylic resin. Nine samples were manufactured by heat-polymerization in water bath and divided into 3 groups: acrylic resin without pigment incorporation (group R), acrylic resin with pigment incorporation (group RP), and acrylic pigment (group P). Eluates formed after 72h of sample immersion in medium were incubated with conjunctival cell line (Chang conjunctival cells) for 72h. The negative control group consisted in medium without samples (group C). The cytotoxic effect from the eluates was evaluated using MTT assay (cell proliferation), ELISA assay (quantification of IL1β, IL6, TNF α and CCL3/MIP1α) and RT-PCR assay (mRNA expression of COL IV, TGF β and MMP9). Data were submitted to ANOVA with Bonferroni post-tests (p<0.05). All groups were considered non-cytotoxic based on cell proliferation. However, resin with pigment incorporation showed significant IL6 quantity increase. Resin without pigment incorporation exhibited higher mRNA expression of COL IV, MMP9 and TGF β, however it was also observed for the negative control group. The materials exhibited divergent biological behavior. Despite the pigment incorporation that resulted in an increase of IL6, no cytotoxicity was observed based on cell proliferation.

  3. Influence of chemical and mechanical polishing on water sorption and solubility of denture base acrylic resins.

    PubMed

    Rahal, Juliana Saab; Mesquita, Marcelo Ferraz; Henriques, Guilherme Elias Pessanha; Nóbilo, Mauro Antonio Arruda

    2004-01-01

    Influence of polishing methods on water sorption and solubility of denture base acrylic resins was studied. Eighty samples were divided into groups: Classico (CL), and QC 20 (QC) - hot water bath cured; Acron MC (AC), and Onda Cryl (ON) - microwave cured; and submitted to mechanical polishing (MP) - pumice slurry, chalk powder, soft brush and felt cone in a bench vise; or chemical polishing (CP) - heated monomer fluid in a chemical polisher. The first desiccation process was followed by storage in distilled water at 37 +/- 1 degrees C for 1 h, 1 day, 1, 2, 3 and 4 weeks. Concluding each period, water sorption was measured. After the fourth week, a second desiccation process was done to calculate solubility. Data were submitted to analysis of variance, followed by Tukey test (pacrylic resins; initially, water sorption values were higher for chemically polished samples, however, after 4 weeks all groups were similar. PMID:15798828

  4. Influence of chemical and mechanical polishing on water sorption and solubility of denture base acrylic resins.

    PubMed

    Rahal, Juliana Saab; Mesquita, Marcelo Ferraz; Henriques, Guilherme Elias Pessanha; Nóbilo, Mauro Antonio Arruda

    2004-01-01

    Influence of polishing methods on water sorption and solubility of denture base acrylic resins was studied. Eighty samples were divided into groups: Classico (CL), and QC 20 (QC) - hot water bath cured; Acron MC (AC), and Onda Cryl (ON) - microwave cured; and submitted to mechanical polishing (MP) - pumice slurry, chalk powder, soft brush and felt cone in a bench vise; or chemical polishing (CP) - heated monomer fluid in a chemical polisher. The first desiccation process was followed by storage in distilled water at 37 +/- 1 degrees C for 1 h, 1 day, 1, 2, 3 and 4 weeks. Concluding each period, water sorption was measured. After the fourth week, a second desiccation process was done to calculate solubility. Data were submitted to analysis of variance, followed by Tukey test (pacrylic resins; initially, water sorption values were higher for chemically polished samples, however, after 4 weeks all groups were similar.

  5. [The evaluation of acrylic resins for the study of nondecalcified human teeth with the light and electronic microscopes].

    PubMed

    Botti, F; Martignoni, M; Scala, C; Cocchia, D

    1995-04-01

    Resin embedding of human teeth for light and transmission electron microscopic studies becomes difficult without previous decalcification. The limited and slow infiltration of the resin into hard tissues may cause problems during preparation and observation of the samples. Moreover the type of resin that is used may affect the morphologic preservation of both tissues and cellular elements. Recently there has been an increasing number of studies on the application of acrylic resins in light and electron microscopy, in order to overcome problems encountered with the use of epoxy resins still utilized in morphologic studies. We compared different acrylic resins (Technovit 7200 VLC, LR White, LR Gold, Bioacryl) in order to understand which one was more suitable for undecalcified human dental tissues under light and transmission electron microscope. Evaluation of such resins was performed using the following criteria: ease of cutting with ultramicrotome, soft and hard tissues infiltration, uptake of tissue stains for both light and electron microscopy, morphologic preservation and stability under electron beam. This study, carried out on the pulp area comprising predentin and dentin, showed excellent quality of Bioacryl and LR Gold, the two resins presenting, by far, the best results among all the different types tested. The optimal morphologic preservation obtained with such resins is indicated for light and electron microscopic studies, allowing their application in different fields of dental research.

  6. Evaluation of shear bond strength of repair acrylic resin to Co-Cr alloy

    PubMed Central

    Külünk, Şafak; Külünk, Tolga; Saraç, Duygu; Baba, Seniha

    2014-01-01

    PURPOSE The purpose of this study was to investigate the impact of different surface treatment methods and thermal ageing on the bond strength of autopolymerizing acrylic resin to Co-Cr. MATERIALS AND METHODS Co-Cr alloy specimens were divided into five groups according to the surface conditioning methods. C: No treatment; SP: flamed with the Silano-Pen device; K: airborne particle abrasion with Al2O3; Co: airborne particle abrasion with silica-coated Al2O3; KSP: flamed with the Silano-Pen device after the group K experimental protocol. Then, autopolymerized acrylic resin was applied to the treated specimen surfaces. All the groups were divided into two subgroups with the thermal cycle and water storage to determine the durability of the bond. The bond strength test was applied in an universal test machine and treated Co-Cr alloys were analyzed by scanning electron microscope (SEM). Two-way analysis of variance (ANOVA) was used to determine the significant differences among surface treatments and thermocycling. Their interactons were followed by a multiple comparison' test performed uing a post hoc Tukey HSD test (α=.05). RESULTS Surface treatments significantly increased repair strengths of repair resin to Co-Cr alloy. The repair strengths of Group K, and Co significantly decreased after 6,000 cycles (P<.001). CONCLUSION Thermocycling lead to a significant decrease in shear bond strength for air abrasion with silica-coated aluminum oxide particles. On the contrary, flaming with Silano-Pen did not cause a significant reduction in adhesion after thermocycling. PMID:25177470

  7. Using Latex Balls and Acrylic Resin Plates to Investigate the Stacking Arrangement and Packing Efficiency of Metal Crystals

    ERIC Educational Resources Information Center

    Ohashi, Atsushi

    2015-01-01

    A high-school third-year or undergraduate first-semester general chemistry laboratory experiment introducing simple-cubic, face-centered cubic, body-centered cubic, and hexagonal closest packing unit cells is presented. Latex balls and acrylic resin plates are employed to make each atomic arrangement. The volume of the vacant space in each cell is…

  8. The Effect of 3-Isocyanato-1-Propene on Adhesive Properties of UV-Curing Urethane/Siloxane Acrylate Resin.

    PubMed

    Chun, J H; Cheon, J M; Jeong, B Y; Jo, N J

    2016-03-01

    We synthesized the urethane/siloxane acrylate oligomer from isophorone diisocyanate (IPDI), hydroxyl alkyl terminated polydimethylsiloxane and 2-hydroxyethyl acrylate (2-HEA). UV-curable resins were formulated from the synthesized oligomer, ethylene glycol phenyl ether acrylate (PHEA), 1,6-hexanediol diacrylate (HDDA), trimethylolpropane triacrylate (TMPTA) as a reactive diluent, 3-isocyanato-1-propene as an adhesion promoter and photoinitiators. The PET film was treated with plasma in order to introduce the functional group on the PET surface and the functional group was observed through X-ray photoelectron spectroscopy (XPS) and the Fourier transform infrared (FT-IR). The adhesion strength between the PET film and the UV-cured resin were increased by using the adhesion promoter. Also, the thermal stability, the modulus and surface hardness were increased, as the adhesion promoter was added.

  9. Characterization of acrylic resins used for restoration of artworks by pyrolysis-silylation-gas chromatography/mass spectrometry with hexamethyldisilazane.

    PubMed

    Osete-Cortina, Laura; Doménech-Carbó, María Teresa

    2006-09-15

    A procedure based on the technique of the pyrolysis-GC/MS has been applied, in this work, in order to determine the composition of synthetic acrylic resins employed in artworks. The method is based on the on line derivatization of these resins using hexamethyldisilazane (HMDS). Results obtained have been compared with those others from direct pyrolysis and in situ thermally assisted hydrolysis and methylation with tetramethylammonium hydroxide (TMAH). Sensitivity using HMDS as derivatising reagent is found similar to that from direct pyrolysis and methylation with TMAH. Better resolution of the most representative peaks has been also obtained. Additionally, this method reduces the formation of free acrylic acid molecules during the pyrolysis process and, in consequence, more simplified and well-resolved chromatograms are obtained. Finally, the reported procedure has been successfully used for characterizing several acrylic-based varnishes and binding media currently used in Fine Arts and real pictorial samples from graffiti performed on a Middle Ages bridge.

  10. Colour stability of acrylic resin denture teeth after immersion in different beverages.

    PubMed

    Arana-Correa, B E; Sepúlveda-Navarro, W F; Florez, F L E; Urban, V M; Jorge, J H; Campanha, N H

    2014-06-01

    The colour stability of acrylic resin denture teeth in beverages was investigated. A spectrophotometer measured the colour (CIE-L*a*b* system) of all specimens after storage in distilled water/for 24 h at 37 degrees C (T0). Specimens were then immersed in various beverages. After 15 days (T1) and 30 days (T2), for each material, the mean deltaE values were calculated and compared by two-way ANOVA and Tukey intervals (alpha = 0.05). In the deltaT0T1 period, specimens stored in red wine were significantly discoloured, compared to distilled water (P = 0.003). There was no difference between immersion solutions in deltaET0T2 (P = 0.772) and in deltaET1T2 (P = 0.058), and no difference between materials in all immersion periods.

  11. Prediction of capacity factors for aqueous organic solutes adsorbed on a porous acrylic resin

    USGS Publications Warehouse

    Thurman, E.M.

    1978-01-01

    The capacity factors of 20 aromatic, allphatic, and allcycllc organic solutes with carboxyl, hydroxyl, amine, and methyl functional groups were determined on Amberlite XAD-8, a porous acrylic resin. The logarithm of the capacity factor, k???, correlated inversely with the logarithm of the aqueous molar solubility with significance of less than 0.001. The log k???-log solubility relationship may be used to predict the capacity of any organic solute for XAD-8 using only the solubility of the solute. The prediction is useful as a guide for determining the proper ratio of sample to column size In the preconcentration of organic solutes from water. The inverse relationship of solubility and capacity is due to the unfavorable entropy of solution of organic solutes which affects both solubility and sorption.

  12. Comparative evaluation of shear compressive bond strength between cross-linked acrylic resin denture base and cross-linked acrylic resin teeth with different modifcations of their ridge lap surfaces.

    PubMed

    Sadar, Leena; Dhume, Swaroop; Maniar, Neena; Prakash Patil, Jeevan; Rane, Prasad; Gandhewar, Mahesh

    2013-09-01

    A major problem commonly observed in denture wearer is the detachment of artifcial tooth/teeth from acrylic denture base. The problem was grave when porcelain teeth used along with the then available denture base materials. The bond formed was purely mechanical and hence debonding of teeth from denture base was a frequent occurrence. Inspite of chemical union between acrylic resin teeth and acrylic denture base material, detachment of teeth particularly anterior teeth is a frequent observation. The objective of the study is to study the effect of change in the surface treatment and surface confguration of ridge lap surface of the teeth on retention of cross-linked acrylic teeth on cross-linked acrylic resin denture base. Sixty specimens were tested for the shear compressive bond strength using instron universal testing machine in KN. Statistical analysis is used. The fndings were analyzed using one-way analysis of variance (ANOVA) and 't' test. Slight modifcation in the ridge lap surface of artifcial teeth alters the strength of the shear compressive bond. Sand papering of ridge lap surfaces improves the shear compressive bond then the one without any modifcation. Maximum shear compressive bond strength can be increased by application of monomer.

  13. Mechanical and biological properties of acrylic resins manipulated and polished by different methods.

    PubMed

    dos Santos, Rogério Lacerda; Pithon, Matheus Melo; Carvalho, Fabiola Galbiatti; Ramos, Aretha Aliny dos Santos; Romanos, Maria Teresa Villela

    2013-01-01

    This study evaluated the influence of the manipulation technique and polishing method on the flexural strength and cytotoxicity of acrylic resins. Two manipulation techniques and three polishing methods were used in the fabrication of acrylic plates that were divided into 6 groups (n=10). Groups MM, MC and MW: mass technique with mechanical polishing, chemical polishing and without polishing, respectively; and Groups SM, SC and SW: Saturation technique with mechanical polishing, chemical polishing and without polishing, respectively). Flexural strength was tested in a universal testing machine and the cytotoxicity assay used cell cultures (L-929) for periods of 24 h to 168 h. Flexural strength and cytotoxicity data were assessed using two-way and three-way ANOVA, respectively (α=0.05), followed by post hoc Bonferroni test for multiple comparisons. The effect of combinations of manipulation techniques and polishing methods on flexural strength showed significant differences only between Group SC and Groups MW, MM and MC (p<0.01). Cell viability ranged from 51% (3.9%) to 87,6% (3.2) in the 24-h time interval, and from 87.8% (5.0) to 95.7% (3.1%) in the 168-h time interval. With the increase of cell viability, from the third day (72 h), there was no significant difference among the groups, except between MM and SC (p<0.01) at 72 h. In conclusion, the manipulation technique and polishing method had more influence on the cytotoxicity than on flexural strength.

  14. Antifungal Effect of Henna against Candida albicans Adhered to Acrylic Resin as a Possible Method for Prevention of Denture Stomatitis.

    PubMed

    Nawasrah, Amal; AlNimr, Amani; Ali, Aiman A

    2016-01-01

    Denture stomatitis is a very common disease affecting the oral mucosa of denture wearers. The aim of this study was to measure the antifungal effect of henna against Candida albicans adhered to acrylic resin as a possible method for prevention of denture stomatitis. One-hundred-eighty acrylic plates were prepared of heat-cured acrylic denture resin. The specimens were divided into six groups of 30 samples each. The first group was only polymer and monomer following the conventional manufacturer instruction for processing complete dentures. The other five groups were processed by adding different concentration of Yamani henna powder (Harazi) to the polymer in a concentration of henna: polymer 1%, 2.5%, 5%, 7.5% and 10%, respectively. Samples were incubated in artificial saliva rich with Candida albicans at 37 °C, and the effect of henna on Candida albicans was evaluated in two different methods: semi-quantitative slide count and a culture-based quantitative assay (quantitative). Variation in the number of live Candida was observed with the increase in the concentration of Yamani henna powder. It was observed that the variation in live Candida, between control group and group B (concentration of Yamani henna powder was 1%), was statistically significant with a p-value of 0.0001. Similarly, variations in live Candida were significant, when the concentration of powder was 7.5% or 10% in contrast with control group and p-values were 0.0001 and 0.001 respectively. Adding henna to acrylic resin denture could be effective in controlling Candida albicans proliferation on the denture surface; however, its effects on the physical properties of acrylic resin denture need further studies. PMID:27223294

  15. Antifungal Effect of Henna against Candida albicans Adhered to Acrylic Resin as a Possible Method for Prevention of Denture Stomatitis.

    PubMed

    Nawasrah, Amal; AlNimr, Amani; Ali, Aiman A

    2016-05-23

    Denture stomatitis is a very common disease affecting the oral mucosa of denture wearers. The aim of this study was to measure the antifungal effect of henna against Candida albicans adhered to acrylic resin as a possible method for prevention of denture stomatitis. One-hundred-eighty acrylic plates were prepared of heat-cured acrylic denture resin. The specimens were divided into six groups of 30 samples each. The first group was only polymer and monomer following the conventional manufacturer instruction for processing complete dentures. The other five groups were processed by adding different concentration of Yamani henna powder (Harazi) to the polymer in a concentration of henna: polymer 1%, 2.5%, 5%, 7.5% and 10%, respectively. Samples were incubated in artificial saliva rich with Candida albicans at 37 °C, and the effect of henna on Candida albicans was evaluated in two different methods: semi-quantitative slide count and a culture-based quantitative assay (quantitative). Variation in the number of live Candida was observed with the increase in the concentration of Yamani henna powder. It was observed that the variation in live Candida, between control group and group B (concentration of Yamani henna powder was 1%), was statistically significant with a p-value of 0.0001. Similarly, variations in live Candida were significant, when the concentration of powder was 7.5% or 10% in contrast with control group and p-values were 0.0001 and 0.001 respectively. Adding henna to acrylic resin denture could be effective in controlling Candida albicans proliferation on the denture surface; however, its effects on the physical properties of acrylic resin denture need further studies.

  16. Antifungal Effect of Henna against Candida albicans Adhered to Acrylic Resin as a Possible Method for Prevention of Denture Stomatitis

    PubMed Central

    Nawasrah, Amal; AlNimr, Amani; Ali, Aiman A.

    2016-01-01

    Denture stomatitis is a very common disease affecting the oral mucosa of denture wearers. The aim of this study was to measure the antifungal effect of henna against Candida albicans adhered to acrylic resin as a possible method for prevention of denture stomatitis. One-hundred-eighty acrylic plates were prepared of heat-cured acrylic denture resin. The specimens were divided into six groups of 30 samples each. The first group was only polymer and monomer following the conventional manufacturer instruction for processing complete dentures. The other five groups were processed by adding different concentration of Yamani henna powder (Harazi) to the polymer in a concentration of henna: polymer 1%, 2.5%, 5%, 7.5% and 10%, respectively. Samples were incubated in artificial saliva rich with Candida albicans at 37 °C, and the effect of henna on Candida albicans was evaluated in two different methods: semi-quantitative slide count and a culture-based quantitative assay (quantitative). Variation in the number of live Candida was observed with the increase in the concentration of Yamani henna powder. It was observed that the variation in live Candida, between control group and group B (concentration of Yamani henna powder was 1%), was statistically significant with a p-value of 0.0001. Similarly, variations in live Candida were significant, when the concentration of powder was 7.5% or 10% in contrast with control group and p-values were 0.0001 and 0.001 respectively. Adding henna to acrylic resin denture could be effective in controlling Candida albicans proliferation on the denture surface; however, its effects on the physical properties of acrylic resin denture need further studies. PMID:27223294

  17. Comparison of Adhesive Resistance to Chewing Gum among Denture Base Acrylic Resin, Cobalt-Chromium Alloy, and Zirconia.

    PubMed

    Wada, Takeshi; Takano, Tomofumi; Ueda, Takayuki; Sakurai, Kaoru

    2016-01-01

    The purpose of this study was to compare the adhesiveness of chewing gum to acrylic resin, cobalt-chromium alloy, and zirconia. Test specimens were fabricated using acrylic resin (resin), cobalt-chromium alloy (Co-Cr), and Ceria stabilized tetragonal zirconia polycrystal-based nanostructured zirconia/alumina composite (zirconia). Specimens of each material were attached to the upper and lower terminals of a digital force gauge. The operator masticated chewing gum, wiped off any saliva, and placed the gum on the lower specimen. The gum was compressed to a thickness of 1 mm between the upper and lower specimens. Thereafter, traction was applied to the upper specimen at a cross-head speed of 100 mm/min under 3 different conditions (dry, wet with distilled water, and wet with artificial saliva) to determine the maximum adhesive strength of the chewing gum. The statistical analysis was performed using the Bonferroni test after a one-way analysis of variance (α=0.05). Under dry conditions, adhesive force was 14.8±6.8 N for resin, 14.0±4.8 N for Co-Cr, and 4.3±2.3 N for zirconia. Significant differences were noted between resin and zirconia, and between Co-Cr and zirconia. When distilled water was applied to the specimen surface, the adhesive strength was 16.8±1.7 N for resin, 8.3±2.1 N for Co-Cr, and 2.7±0.8 N for zirconia. Significant differences were noted between resin and Co-Cr, resin and zirconia, and Co-Cr and zirconia. When artificial saliva was applied to the specimen surface, the adhesive force was 18.5±2.8 N for resin, 5.3±0.8 N for Co-Cr, and 3.0±1.7 N for zirconia. Significant differences were noted between resin and Co-Cr, and resin and zirconia. Chewing gum adhered less strongly to zirconia than to acrylic resin or cobalt-chromium alloy. PMID:26961330

  18. Comparison of Adhesive Resistance to Chewing Gum among Denture Base Acrylic Resin, Cobalt-Chromium Alloy, and Zirconia.

    PubMed

    Wada, Takeshi; Takano, Tomofumi; Ueda, Takayuki; Sakurai, Kaoru

    2016-01-01

    The purpose of this study was to compare the adhesiveness of chewing gum to acrylic resin, cobalt-chromium alloy, and zirconia. Test specimens were fabricated using acrylic resin (resin), cobalt-chromium alloy (Co-Cr), and Ceria stabilized tetragonal zirconia polycrystal-based nanostructured zirconia/alumina composite (zirconia). Specimens of each material were attached to the upper and lower terminals of a digital force gauge. The operator masticated chewing gum, wiped off any saliva, and placed the gum on the lower specimen. The gum was compressed to a thickness of 1 mm between the upper and lower specimens. Thereafter, traction was applied to the upper specimen at a cross-head speed of 100 mm/min under 3 different conditions (dry, wet with distilled water, and wet with artificial saliva) to determine the maximum adhesive strength of the chewing gum. The statistical analysis was performed using the Bonferroni test after a one-way analysis of variance (α=0.05). Under dry conditions, adhesive force was 14.8±6.8 N for resin, 14.0±4.8 N for Co-Cr, and 4.3±2.3 N for zirconia. Significant differences were noted between resin and zirconia, and between Co-Cr and zirconia. When distilled water was applied to the specimen surface, the adhesive strength was 16.8±1.7 N for resin, 8.3±2.1 N for Co-Cr, and 2.7±0.8 N for zirconia. Significant differences were noted between resin and Co-Cr, resin and zirconia, and Co-Cr and zirconia. When artificial saliva was applied to the specimen surface, the adhesive force was 18.5±2.8 N for resin, 5.3±0.8 N for Co-Cr, and 3.0±1.7 N for zirconia. Significant differences were noted between resin and Co-Cr, and resin and zirconia. Chewing gum adhered less strongly to zirconia than to acrylic resin or cobalt-chromium alloy.

  19. Influence of nanoparticles on color stability, microhardness, and flexural strength of acrylic resins specific for ocular prosthesis.

    PubMed

    Andreotti, Agda Marobo; Goiato, Marcelo Coelho; Moreno, Amália; Nobrega, Adhara Smith; Pesqueira, Aldiéris Alves; dos Santos, Daniela Micheline

    2014-01-01

    The aim of this study was to assess the effect of adding nanoparticles to N1 acrylic resin intended for artificial sclera, in terms of the color stability, microhardness, and flexural strength of the resin. Three hundred samples of N1 acrylic resin were used: 100 samples for color stability and microhardness tests (each test was performed on the opposite side of each sample), and 200 samples for flexural strength testing (100 samples before and after 1,008 hours of accelerated aging). Samples for each test were separated into ten groups (n=10), ie, without nanoparticles (control group) or with nanoparticles of zinc oxide, titanium dioxide (TiO₂), and barium sulfate at weight concentrations of 1%, 2%, and 2.5% (nanoparticle groups). Data were subjected to statistical analysis with nested analysis of variance and Tukey's test (P<0.05 significance level). Among the nanoparticle groups, the TiO₂ groups showed better color stability at all concentrations. Microhardness values increased after artificial aging, except for the control and zinc oxide groups. After aging, the 1%-2% TiO₂ groups had significantly higher microhardness values compared with the other nanoparticle groups. Before aging, there was a significant difference in flexural strength between the control and nanoparticle groups. After aging, the control and TiO₂ groups, regardless of concentration, showed the lowest flexural strength values. Incorporation of nanoparticles directly influenced the acrylic resin properties, with TiO₂ being the most influential nanoparticle in terms of the evaluated properties.

  20. Effect of toothbrushes and denture brushes on heat-polymerized acrylic resins.

    PubMed

    de Freitas Pontes, Karina Matthes; de Holanda, Janaína Câncio; Fonteles, Cristiane Sa Roriz; Pontes, Cassio de Barros; Lovato da Silva, Cláudia Helena; Paranhos, Helena de Freitas Oliveira

    2016-01-01

    It is important to choose an appropriate brush for denture cleaning to prevent damage to the surface properties of prosthetic devices. The purpose of this study was to evaluate the abrasiveness of toothbrushes and denture brushes on boiled and microwave-processed acrylic resins. Specimens of 4 resin brands were prepared (n = 30). Five brands of brushes (n = 6) were used in a toothbrushing machine, first for 17,800 strokes and then for an additional 35,600 strokes (total of 53,400), at a load of 200 g. An analytical balance and a profilometer were used to assess the weight and surface roughness, respectively, before and after 17,800 and 53,400 strokes. Analysis of variance and Tukey tests were used for data analysis (α = 0.05). Weight loss increased with time, while surface roughness remained the same. There were no statistically significant differences among toothbrushes and denture brushes in the resulting weight loss (17,800 strokes, 1.83 mg; 53,400 strokes, 3.78 mg) or surface roughness (17,800 or 53,400 strokes, 0.14 µm). The weight loss values after 53,400 brush strokes indicated that Clássico (2.28 mg) and VIPI Wave (2.75 mg) presented significantly greater abrasion resistance than Lucitone 550 (3.36 mg) and Onda-Cryl (2.85 mg) (P < 0.05). The type of brush and the polymerization method did not influence resin wear after brushing.

  1. Effect of cervical relining of acrylic resin copings on the accuracy of stone dies obtained using a polyether impression material.

    PubMed

    de Sá, André Tomazini Gomes; de Freitas, César Antunes; de Sá, Fátima Cristina; Ursi, Wagner José Silva; Simões, Tânia Christina; de Freitas, Márcia Furtado Antunes

    2008-01-01

    The purpose of this study was to evaluate the accuracy of the respective dies after polyether elastomeric procedure in the presence or absence of cervical contact of the acrylic resin shell with the cervical region, establishing a comparison to dies obtained with stock trays. This study consisted of three groups with 10 specimens each: 1) acrylic copings without cervical contact, (cn); 2) acrylic copings with cervical contact (cc); 3) perforated stock tray, (st). The accuracy of the resulting dies was verified with the aid of a master crown, precisely fit to the master steel die. ANOVA test found statistically significant differences among groups (p<0.001). Tukey's test found that the smallest discrepancy occurred in group cn, followed by cc, while the st group presented the highest difference (cc x cn: p=0.007; st x cn: p<0.001; st x cc: p<0.001).

  2. Effect of microwave irradiation on the flexural strength and residual monomer levels of an acrylic resin repair material.

    PubMed

    Yunus, N; Harrison, A; Huggett, R

    1994-11-01

    The degree of polymerization of an acrylic resin repair material, as established by residual monomer estimation, was compared using three different polymerization methods, i.e. bench-cure, hydroflask-cure and microwave irradiation cure. The repair strength of a conventional heat-polymerized resin was then assessed following repairs using each of these three methods. The lowest level of residual monomer was achieved with the microwave irradiation cure. It was also demonstrated that of the three methods, polymerization using microwave energy resulted in the strongest repair.

  3. Glutaraldehyde release from heat-polymerized acrylic resins after disinfection and chemical and mechanical polishing.

    PubMed

    Orsi, Iara Augusta; Andrade, Vanessa Gomes; Bonato, Pierina Sueli; Raimundo, Lariça Barbosa; Herzog, Daniella Silva; Borie, Eduardo

    2011-01-01

    This study evaluated the release of glutaraldehyde from heat-polymerized acrylic resins subjected to disinfection followed by chemical and mechanical polishing. Ninety disc-shaped specimens (15 x 4 mm), 30 per resin (Lucitone 550, QC-20 and Classico), were made and assigned to 2 groups according to the type of polishing. One side of each specimen was not polished and the other was either mechanically (n = 45) or chemically (n = 45) polished, and immersed in water at 50 °C for 1 h to allow the release of intrinsic substances and then kept in distilled water for 7 days. The specimens were disinfected by immersion in 2% glutaraldehyde for 10 min. After this period, 3 specimens from each group were immersed in water for 15, 30, 60, 120 and 240 min. For the 15-, 30-, 60-min immersions, 4 water exchanges were done at the end of period. High performance liquid chromatography (HPLC) was used to detect and quantify the glutaraldehyde released after each period. Data were analyzed statistically by two-way ANOVA and multiple comparisons were done by Tukey's and Scheffé's tests (α = 0.05). No glutaraldehyde release was observed from the specimens with chemical polishing at any of the immersion periods, while the mechanically polished specimens released glutaraldehyde. In the groups with water exchanges, Lucitone released more disinfectant in the 15-min period (0.040 μg/mL), Classico in the 30-min (0.021 μg/mL) and 60-min (0.018 μg/mL) periods, and QC-20 the same amount (-1.760 μg/mL) in all periods. In the groups without water exchanges, Lucitone released the highest amount of disinfectant (-1.370 μg/mL), differing significantly from QC-20 (0022 g/mL) and Classico (0019 g/mL), which were similar. The findings of this showed that chemically polished specimens from the 3 resin brands did not release glutaraldehyde after different periods of immersion, while glutaraldehyde release was observed from the mechanically polished specimens, especially from those made of

  4. In vitro adhesion of Candida glabrata to denture base acrylic resin modified by glow-discharge plasma treatment.

    PubMed

    Zamperini, Camila Andrade; Carneiro, Haline de Lima; Rangel, Elidiane Cipriano; Cruz, Nilson Cristino; Vergani, Carlos Eduardo; Machado, Ana Lucia

    2013-03-01

    This study evaluated the potential of plasma treatments to modify the surface chemistry and hydrophobicity of a denture base acrylic resin to reduce the Candida glabrata adhesion. Specimens (n = 54) with smooth surfaces were made and divided into three groups (n = 18): control - non-treated; experimental groups - submitted to plasma treatment (Ar/50 W; AAt/130 W). The effects of these treatments on chemical composition and surface topography of the acrylic resin were evaluated. Surface free energy measurements (SFE) were performed after the treatments and after 48 h of immersion in water. For each group, half (n = 9) of the specimens were preconditionated with saliva before the adhesion assay. The number of adhered C. glabrata was evaluated by cell counting after crystal violet staining. The Ar/50 W and AAt/130 W treatments altered the chemistry composition, hydrophobicity and topography of acrylic surface. The Ar/50 W group showed significantly lower C. glabrata adherence than the control group, in the absence of saliva. After preconditioning with saliva, C. glabrata adherence in experimental and control groups did not differ significantly. There were significant changes in the SFE after immersion in water. The results demonstrated that Ar/50 W treated surfaces have potential for reducing C. glabrata adhesion to denture base resins and deserve further investigation, especially to tailor the parameters to prolong the increased wettability. PMID:22809146

  5. 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.

    PubMed

    Ormianer, Z; Laufer, B Z; Nissan, J; Gross, M

    2000-01-01

    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).

  6. Color change in acrylic resin processed in three ways after immersion in water, cola, coffee, mate and wine.

    PubMed

    Waldemarin, Renato F A; Terra, Priscila C; Pinto, Luciana R; Camacho, Fernanda Faot Guilherme B

    2013-01-01

    Denture bases may undergo color change over time induced by pigment accumulation within their body; however there is a lack of information regarding the role of yerba mate tea in this process. This work evaluated the effect of five common beverages, including yerba mate tea, on color changes of acrylic denture base resins processed in three different ways. Three different processing techniques were used (P1--microwave irradiation/microwave activated resin; P2--heat polymerization/conventional heat activated resin and P3--microwave irradiation/conventional heat polymerized resin) to make twenty five resin discs each (3.0 mm thick x 20 mm diameter), totaling seventy-five resin discs. The discs made with each technique were randomly divided into five groups (n = 5) and placed in the following solutions: G1-water; G2-cola; G3-coffee; G4-yerba mate tea; G5-red wine, for 30 days at 37 degrees C. The solutions were renewed every 3 days. Color change on the CIE-L*a*b* scale was measured with a Konica-Minolta CR-10 colorimeter and compared with original L* a* and b* values of each specimen prior to immersion. Data were analyzed using 2-way ANOVA, and showed no difference among techniques and significant statistical differences among solutions (p < 0.05). Tukey's post-hoc test showed that the lowest color changes were for water and cola, which were undistinguishable from each other; coffee produced the second lowest color change; yerba mate tea produced second greatest color change, while the greatest color change was produced by red wine. Within the limitations of this study, it was concluded that almost all the solutions used can change color in acrylic resin, especially yerba mate tea, considered distinguishable by professionals, and red wine, considered distinguishable by patients and clinically unacceptable.

  7. Effect of Silver Nano-particles on Tensile Strength of Acrylic Resins

    PubMed Central

    Ghaffari, Tahereh; Hamedi-rad, Fahimeh

    2015-01-01

    Background and aims. Polymethyl methacrylate (PMMA) is widely used for the fabrication of removable prostheses. Silver nano-particles (AgNps) have been added to PMMA because of their antimicrobial properties, but their effect on the mechanical properties of PMMA is unknown. The aim of this study was to investigate the effects of AgNps on the tensile strength of PMMA. Materials and methods. For this study, 12 specimens were prepared and divided into two groups. Group 1 included PMMA without AgNps and group 2 included PMMA mixed with 5 wt% of AgNps. Tensile strength of the specimens was measured by Zwick Z100 apparatus. Statistical analysis was carried out by SPSS using t-test. Statistical significance was defined at P<0.05. Results. This study showed that the mean tensile strength of PMMA in group 2 was significantly lower than that in group 1. Therefore, the tensile strength decreased significantly after incorporation of silver nano-particles. Conclusion. Within the limitations of this study, tensile strength of acrylic resin specimens was influenced by silver nano-particles. PMID:25973153

  8. Biofilm-forming ability and adherence to poly-(methyl-methacrylate) acrylic resin materials of oral Candida albicans strains isolated from HIV positive subjects

    PubMed Central

    Uzunoglu, Emel; Dolapci, Istar; Dogan, Arife

    2014-01-01

    PURPOSE This study evaluated the adhesion to acrylic resin specimens and biofilm formation capability of Candida albicans strains isolated from HIV positive subjects' oral rinse solutions. MATERIALS AND METHODS The material tested was a heat-cured acrylic resin (Acron Duo). Using the adhesion and crystal violet assays, 14 oral Candida albicans isolated from HIV-positive subjects and 2 references Candida strains (C. albicans ATCC 90028 and C. albicans ATCC 90128) were compared for their biofilm production and adhesion properties to acrylic surfaces in vitro. RESULTS There were no significant differences in adhesion (P=.52) and biofilm formation assays (P=.42) by statistical analysis with Mann-Whitney test. CONCLUSION Denture stomatitis and increased prevalence of candidal carriage in HIV infected patients is unlikely to be related to the biofilm formation and adhesion abilities of C. albicans to acrylic resin materials. PMID:24605203

  9. Influence of a new denture cleaning technique based on photolysis of H(2)O(2) the mechanical properties and color change of acrylic denture base resin.

    PubMed

    Nakahara, Tatsuro; Harada, Akio; Yamada, Yasutomo; Odashima, Yu; Nakamura, Keisuke; Inagaki, Ryoichi; Kanno, Taro; Sasaki, Keiichi; Niwano, Yoshimi

    2013-01-01

    The purpose of this study was to evaluate the influence of a disinfection technique based on photolysis of H2O2 on the mechanical properties and color change of acrylic denture base resin. Resin specimens were immersed in 1 M H2O2 irradiated with light-emitting diode (LED) light at 400 nm for 1 week. The immersion duration of 1 week (168 h) corresponded to performing approximately 500 times of 20-min cleaning. Hydroxyl radicals are potent oxidants and they were generated via the photolysis of H2O2. Oxidative damage caused by these radicals included reduced flexural strength and altered color for the acrylic resin. Nonetheless, the degraded flexural strength and altered color of acrylic resin after 500 times of cleaning in the disinfection system would be within clinically acceptable levels.

  10. Comparative evaluation of color change between two types of acrylic resin and flexible resin after thermo cycling. An in vitro study.

    PubMed

    Hatim, Nadira A; Al-Tahho, Omar Zeno

    2013-09-01

    Evaluation of the effect of different beverages (tea with sugar, coffee with sugar, and Pepsi), and immersion time cycles (2, 4, and 12 weeks) on color change property, and dimensional change of Vertex Dental BV, Netherlands heat cured acrylic resin, recently modified Vertex Dental BV, Netherlands heat cured acrylic resin with additive (20 % banana oil), and Valplast(®) flexible resin (FR) denture base materials by using artificial saliva cycle. The total samples of this study for color, and dimensional changes were 360 samples, divided into three groups according to the type of the material, Vertex Dental BV, Netherlands heat cured acrylic resin, modified heat cured acrylic resin (Vertex with additive 20 % banana oil), and Valplast(®) FR groups, each group contains 120 samples. The thermal cycling used in this study was as follows: The samples were incubated in distilled water at 37 ± 1 °C for 2 days for conditioning. Then, the samples were immersed in beverage solutions for 10 min daily at 50 ± 1 °C temperature for tea, and coffee with sugar, while for Pepsi at 20 ± 1 °C. Then, the samples were immersed in artificial saliva at 37 ± 1 °C for 5 h, and 10 min. This cycle was repeated three times daily, and then the samples were immersed in distilled water at 22 ± 2 °C room temperature for 8 h at night. This cycle was repeated for 2, 4, and 12 weeks. At the end of each time period, the immersed samples were tested to evaluate the color change property. Descriptive statistics, ANOVA, and Duncan's multiple range tests were used to analyze the collected data. The results of this study showed that, in comparison between the materials at different times for colors L*a*b* properties, there were significant differences at P ≤ 0.05 except in color b* at 12 weeks, which showed no significant difference at P > 0.05 between materials. And there was a significant difference in dimensional change at P > 0.05 for different beverages

  11. Comparative evaluation of color change between two types of acrylic resin and flexible resin after thermo cycling. An in vitro study.

    PubMed

    Hatim, Nadira A; Al-Tahho, Omar Zeno

    2013-09-01

    Evaluation of the effect of different beverages (tea with sugar, coffee with sugar, and Pepsi), and immersion time cycles (2, 4, and 12 weeks) on color change property, and dimensional change of Vertex Dental BV, Netherlands heat cured acrylic resin, recently modified Vertex Dental BV, Netherlands heat cured acrylic resin with additive (20 % banana oil), and Valplast(®) flexible resin (FR) denture base materials by using artificial saliva cycle. The total samples of this study for color, and dimensional changes were 360 samples, divided into three groups according to the type of the material, Vertex Dental BV, Netherlands heat cured acrylic resin, modified heat cured acrylic resin (Vertex with additive 20 % banana oil), and Valplast(®) FR groups, each group contains 120 samples. The thermal cycling used in this study was as follows: The samples were incubated in distilled water at 37 ± 1 °C for 2 days for conditioning. Then, the samples were immersed in beverage solutions for 10 min daily at 50 ± 1 °C temperature for tea, and coffee with sugar, while for Pepsi at 20 ± 1 °C. Then, the samples were immersed in artificial saliva at 37 ± 1 °C for 5 h, and 10 min. This cycle was repeated three times daily, and then the samples were immersed in distilled water at 22 ± 2 °C room temperature for 8 h at night. This cycle was repeated for 2, 4, and 12 weeks. At the end of each time period, the immersed samples were tested to evaluate the color change property. Descriptive statistics, ANOVA, and Duncan's multiple range tests were used to analyze the collected data. The results of this study showed that, in comparison between the materials at different times for colors L*a*b* properties, there were significant differences at P ≤ 0.05 except in color b* at 12 weeks, which showed no significant difference at P > 0.05 between materials. And there was a significant difference in dimensional change at P > 0.05 for different beverages

  12. Influence of nanoparticles on color stability, microhardness, and flexural strength of acrylic resins specific for ocular prosthesis

    PubMed Central

    Andreotti, Agda Marobo; Goiato, Marcelo Coelho; Moreno, Amália; Nobrega, Adhara Smith; Pesqueira, Aldiéris Alves; dos Santos, Daniela Micheline

    2014-01-01

    The aim of this study was to assess the effect of adding nanoparticles to N1 acrylic resin intended for artificial sclera, in terms of the color stability, microhardness, and flexural strength of the resin. Three hundred samples of N1 acrylic resin were used: 100 samples for color stability and microhardness tests (each test was performed on the opposite side of each sample), and 200 samples for flexural strength testing (100 samples before and after 1,008 hours of accelerated aging). Samples for each test were separated into ten groups (n=10), ie, without nanoparticles (control group) or with nanoparticles of zinc oxide, titanium dioxide (TiO2), and barium sulfate at weight concentrations of 1%, 2%, and 2.5% (nanoparticle groups). Data were subjected to statistical analysis with nested analysis of variance and Tukey’s test (P<0.05 significance level). Among the nanoparticle groups, the TiO2 groups showed better color stability at all concentrations. Microhardness values increased after artificial aging, except for the control and zinc oxide groups. After aging, the 1%–2% TiO2 groups had significantly higher microhardness values compared with the other nanoparticle groups. Before aging, there was a significant difference in flexural strength between the control and nanoparticle groups. After aging, the control and TiO2 groups, regardless of concentration, showed the lowest flexural strength values. Incorporation of nanoparticles directly influenced the acrylic resin properties, with TiO2 being the most influential nanoparticle in terms of the evaluated properties. PMID:25525359

  13. The effect of time and storage environment on dimensional changes of acrylic resin post patterns.

    PubMed

    Sabouhi, Mahmoud; Nosouhian, Saied; Dakhilalian, Mansour; Davoudi, Amin; Mehrad, Ramin

    2015-01-01

    Introduction : Post and core are needed to regain retentions and functions after endodontic therapies. Also, risk of cross contamination from dental prosthesis is so high. The aim of this study was to compare dimensional changes of acrylic resin patterns (ARP) in three different storing environments. Materials and methods : conventional root canal therapy was done on one first premolar tooth and the canal filled with Guttapercha. 2/3 of the filling was expelled and 30 direct APRs were prepared by Duralay. The samples were divided into 3 groups based on storing environments: water, NaOCl 5% and air. Finally dimensional changes in coronoapical length (CAL), coronal (CD) and apical diameter (AD) of APRs were measured in 7 consecutive times (immediately after polymerization, 1, 2, 4, 8, 24, 48 hours later). All the data were analyzed by Paired T-test and Duncon test using SPSS software ver.13 at significant level of 0.05. Results : After 24 hours, the ARPs, which were stored in air, contracted 0.07, 0.06 and 0.12 mm in AD, CD and CAL; the ARPs, which were stored in water, showed 0.03, 0.06 and 0.12 mm decrease in AD, CD and CAL; But the ARPs, which were stored in NaOCl 5%, showed significant expansion in AD, CD and CAL (0.03, 0.06 and 0.10 mm) (all P values < 0.01). Conclusion : It is better not to use NaOCl for disinfecting; also the best time for storing APRs is 8 hours for water and 2 hours for air environments after setting time.

  14. Synthesis and characterization of a sphere-like modified chitosan and acrylate resin composite for organics absorbency

    NASA Astrophysics Data System (ADS)

    Xin, S. S.; Wang, Y. H.; Li, Q. R.; Zhang, Q.; Wang, X. P.

    2015-07-01

    In this study, the chitosan (deacetylation degree >95%) was modified with vinyltriethoxysilane (A151) and became hydrophobic. The modified chitosan and acrylate resin composite can be synthesized by butyl methacrylate (BMA), butyl acrylate (BA), poly vinyl alcoho(PVA), N,N’-methylene bisacrylamide (MBA), benzoyl peroxide (BPO), and ethyl acetate under microwave irradiation. The optimal synthetic condition was as follows: the molar ratio of BA and BMA was 1.5:1, the dosage of ethyl acetate, PVA, MBA, BPO and modified chitosan were 50 wt.%, 10 wt.%, 1.5 wt.%, 2.0 wt.% and 1.0 wt.% of monomers, respectively. The adsorption capacity of the composite for CHCl3 and CCl4 were approximate to 53 g/g and 44 g/g, respectively. The organics absorbency and regeneration of the samples were also tested, and the samples were characterized by analysis of the scanning electron microscope and simultaneous thermo gravimetric/differential thermal.

  15. The effect of mechanical and chemical polishing techniques on the surface roughness of heat-polymerized and visible light-polymerized acrylic denture base resins

    PubMed Central

    Al-Kheraif, Abdul Aziz Abdullah

    2014-01-01

    Objective The purpose of this study was to compare the effects of mechanical polishing (MP) and chemical polishing (CP) on the average surface roughness (Ra) of heat-cured (HC) and light-cured (LC) denture base acrylic resins. Methods A total of 120 specimens (30 × 15 × 3 mm) were prepared from one HC and one LC acrylic resin. To remove nodules and gross surface irregularities, all specimens were finished with a lathe-mounted small acrylic bur and 360-grit sandpaper. Ten finished specimens of each acrylic resin were randomly assigned to each of six polishing techniques: Resilit High-luster Polishing Liquid (RHPL), Universal Polishing Paste, Abraso-star K50, pumice, Jet Seal Liquid, or Acrypoint. MP was performed with an automatic polishing machine for 2 min, under 50 rpm and 500 g of load. CP was performed by immersing the HC and LC specimens in preheated methyl methacrylate at 75 ± 1 °C for 10 s. The surface roughness of the acrylic resin specimens was measured with a contact profilometer. The Ra values were analyzed by two-way analysis of variance, post hoc Scheffe's test, and paired t-test (p ⩽ 0.05). Polished and tested acrylic resin surfaces were evaluated by scanning electron microscopy. Results MP was more effective than CP. The smoothest surface was obtained with the use of the RHPL on the LC (0.05 ± 0.01 μm) or HC (0.07 ± 0.01 μm) acrylic resin. Two-way ANOVA showed a statistically significant difference between MP and CP. Conclusions MP produced the smoothest surface of denture base acrylic resin. The mean surface roughness values after MP and CP were not influenced by the type of acrylic resin. PMID:25408597

  16. Encapsulation of photocells with acrylic prepolymer

    SciTech Connect

    Avenel, M.; Evrard, P.; Leca, J.-P.

    1985-10-22

    Acrylic prepolymer comprising: from 10 to 50% by weight of units derived from at least one alkyl acrylate, the alkyl group having from 4 to 12 carbon atoms, from 30 to 60% by weight of units derived from at least one alkyl methacrylate, the alkyl group having from 1 to 5 carbon atoms, and from 10 to 40% by weight of units derived from methyl acrylate. The prepolymer is used to encapsulate photocells, connected to one another by conducting wires and positioned on a support plate, by casting a resin into the space located between the support plate and a second protective plate, the resin being obtained by mixing 100 parts of the acrylic prepolymer, from 0.1 to 4 parts of a vanadium arenesulphonate and from 0.5 to 4 parts of a free-radical initiator, at a temperature between 10 and 70 C. and for a sufficient time to solidify the polymeric resin at the temperature selected.

  17. 40 CFR 414.40 - Applicability; description of the thermoplastic resins subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... *ABS-SAN Resins *Acrylate-Methacrylate Latexes *Acrylic Latex *Acrylic Resins *Cellulose Acetate... *Polystyrene—Acrylic Latexes Polystyrene Impact Resins Polystyrene Latex Polystyrene, Expandable Polystyrene... Copolymers *Polyvinylacetate Acrylic Copolymers *Polyvinylacetate-2-Ethylhexylacrylate...

  18. 40 CFR 414.40 - Applicability; description of the thermoplastic resins subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... *ABS-SAN Resins *Acrylate-Methacrylate Latexes *Acrylic Latex *Acrylic Resins *Cellulose Acetate... *Polystyrene—Acrylic Latexes Polystyrene Impact Resins Polystyrene Latex Polystyrene, Expandable Polystyrene... Copolymers *Polyvinylacetate Acrylic Copolymers *Polyvinylacetate-2-Ethylhexylacrylate...

  19. 40 CFR 414.40 - Applicability; description of the thermoplastic resins subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... *ABS-SAN Resins *Acrylate-Methacrylate Latexes *Acrylic Latex *Acrylic Resins *Cellulose Acetate... *Polystyrene—Acrylic Latexes Polystyrene Impact Resins Polystyrene Latex Polystyrene, Expandable Polystyrene... Copolymers *Polyvinylacetate Acrylic Copolymers *Polyvinylacetate-2-Ethylhexylacrylate...

  20. 40 CFR 414.40 - Applicability; description of the thermoplastic resins subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... *ABS-SAN Resins *Acrylate-Methacrylate Latexes *Acrylic Latex *Acrylic Resins *Cellulose Acetate... *Polystyrene—Acrylic Latexes Polystyrene Impact Resins Polystyrene Latex Polystyrene, Expandable Polystyrene... Copolymers *Polyvinylacetate Acrylic Copolymers *Polyvinylacetate-2-Ethylhexylacrylate...

  1. Effect of conventional water-bath and experimental microwave polymerization cycles on the flexural properties of denture base acrylic resins.

    PubMed

    Spartalis, Guilherme Kloster; Cappelletti, Lucas Kravchychyn; Schoeffel, Amanda Cristina; Michél, Milton Domingos; Pegoraro, Thiago Amadei; Arrais, César Augusto Galvão; Neppelenbroek, Karin Hermana; Urban, Vanessa Migliorini

    2015-01-01

    The effect of polymerization cycles on flexural properties of conventional (Vipi Cril(®)-VC) or microwave-processed (Vipi Wave(®)-VW) denture base acrylic resins was evaluated. Specimens (n=10) were submitted to the cycles: WB=65ºC for 1 h+1 h boiling water (VC cycle); M630/25=10 min at 270 W+5 min at 0 W+10 min at 360 W (VW cycle); M650/5=5 min at 650 W; M700/4=4 min at 700 W; and M550/3=3 min at 550 W. Specimens were submitted to a three-point bending test at 5 mm/min until fracture. Flexural strength (MPa) and elastic modulus (GPa) data were analyzed by 2-way ANOVA/Tukey HSD (α=0.05). Overall, VC showed higher values than VW. The results obtained with microwave polymerization did not differ from those obtained with water-bath for both acrylic resins. The results observed when polymerization cycles using medium power and shorter time were used did not differ from those when manufacturer's recommended microwave cycle was applied. Conventional VC might be microwave-processed without compromising its flexural properties. PMID:26438986

  2. The use of acrylic resin oral prosthesis in radiation therapy of oral cavity and paranasal sinus cancer

    SciTech Connect

    Cheng, V.S.T.; Oral, K.; Aramamy, M.A.

    1982-07-01

    In radiation therapy of cancer of the oral cavity and the paranasal sinuses, the extent to which the tissues of the oral cavity are included in the radiation treatment portals will determine the severity of the oral discomfort during treatment. This will affect the nutritional status of the patients, and may eventually affect the total dose of radiation which the patients can receive for treatment of their cancers. In cooperation with the Maxillofacial Prosthetic Department, an acrylic resin oral prosthesis was developed. This prosthesis is easy to use and can be made for each individual patient within 24 hours. It allows for maximum sparing of the normal tissues in the oral cavity and can be modified for shielding of backscattered electrons from heavy metals in the teeth. We have also found that acrylic resin extensions can be built onto the posterior edge of post-maxillectomy obturators; this extension can be used as a carrier for radioactive sources to deliver radiation to deep seated tumor modules in the paranasal sinuses.

  3. Effect of conventional water-bath and experimental microwave polymerization cycles on the flexural properties of denture base acrylic resins.

    PubMed

    Spartalis, Guilherme Kloster; Cappelletti, Lucas Kravchychyn; Schoeffel, Amanda Cristina; Michél, Milton Domingos; Pegoraro, Thiago Amadei; Arrais, César Augusto Galvão; Neppelenbroek, Karin Hermana; Urban, Vanessa Migliorini

    2015-01-01

    The effect of polymerization cycles on flexural properties of conventional (Vipi Cril(®)-VC) or microwave-processed (Vipi Wave(®)-VW) denture base acrylic resins was evaluated. Specimens (n=10) were submitted to the cycles: WB=65ºC for 1 h+1 h boiling water (VC cycle); M630/25=10 min at 270 W+5 min at 0 W+10 min at 360 W (VW cycle); M650/5=5 min at 650 W; M700/4=4 min at 700 W; and M550/3=3 min at 550 W. Specimens were submitted to a three-point bending test at 5 mm/min until fracture. Flexural strength (MPa) and elastic modulus (GPa) data were analyzed by 2-way ANOVA/Tukey HSD (α=0.05). Overall, VC showed higher values than VW. The results obtained with microwave polymerization did not differ from those obtained with water-bath for both acrylic resins. The results observed when polymerization cycles using medium power and shorter time were used did not differ from those when manufacturer's recommended microwave cycle was applied. Conventional VC might be microwave-processed without compromising its flexural properties.

  4. Color degradation of acrylic resin denture teeth as a function of liquid diet: ultraviolet-visible reflection analysis.

    PubMed

    Hipólito, Ana Carolina; Barão, Valentim A; Faverani, Leonardo P; Ferreira, Mayara B; Assunção, Wirley G

    2013-10-01

    The effect of different beverages on acrylic resin denture teeth color degradation is evaluated. Ten acrylic resin denture teeth brands were evaluated: Art Plus (AP), Biolux (BX), Biotone IPN (BI), Magister (MG), Mondial 6 (MD), Premium 6 (PR), SR Vivodent PE (SR), Trilux (TR), Trubyte Biotone (TB), and Vipi Dent Plus (VP). Teeth were immersed in staining solutions (coffee, cola, and orange juice) or artificial saliva (control) (n=6) for 1, 7, 15, or 30 days. Specimen colors were evaluated spectrophotometrically based on the Commission Internationale d'Eclairage L*a*b* system. Color differences (ΔE) were calculated between the baseline and post-staining results. Data were evaluated by analysis of variance and Tukey test (α = 0.05). BI (1.82 ± 0.95) and TR (1.78 ± 0.72) teeth exhibited the greatest ΔE values, while BX (0.88 ± 0.43) and MD (1.09 ± 0.44) teeth were the lowest, regardless of solution and measurement period, and were different from BI and TR teeth (P < 0.05). Cola and coffee promoted higher denture teeth color alterations than orange juice and saliva (P < 0.05). Saliva generated the lowest denture teeth color alterations. Greater immersion times caused higher denture teeth color changes. The lifespan of removable dentures and the aesthetic satisfaction of several edentulous patients may be increased with the use of stain-resistant artificial denture teeth.

  5. Antimicrobial properties of poly (methyl methacrylate) acrylic resins incorporated with silicon dioxide and titanium dioxide nanoparticles on cariogenic bacteria

    PubMed Central

    Sodagar, Ahmad; Khalil, Soufia; Kassaee, Mohammad Zaman; Shahroudi, Atefe Saffar; Pourakbari, Babak; Bahador, Abbas

    2016-01-01

    Aim: To assess the effects of adding nano-titanium dioxide (nano-TiO2) and nano-silicon dioxide (nano-SiO2) and their mixture to poly (methyl methacrylate) (PMMA) to induce antimicrobial activity in acrylic resins. Materials and Methods: Acrylic specimens in size of 20 mm × 20 mm × 1 mm of 0.5% and 1% of nano-TiO2 (21 nm) and nano-SiO2 (20 nm) and their mixture (TiO2/SiO2 nanoparticles) (1:1 w/w) were prepared from the mixture of acrylic liquid containing nanoparticles and acrylic powder. To obtain 0.5% and 1% concentration, 0.02 g and 0.04 g of the nanoparticles was added to each milliliter of the acrylic monomer, respectively. Antimicrobial properties of six specimens of these preparations, as prepared, were assessed against planktonic Lactobacillus acidophilus and Streptococcus mutans at 0, 15, 30, 45, 60, 75, and 90 min follow-up by broth dilution assay. The specimens of each group were divided into three subgroups: Dark, daylight, or ultraviolet A (UVA). The percent of bacterial reduction is found out from the counts taken at each time point. Statistical Analysis: Data were analyzed using one-way analysis of variance and Tukey's post hoc analysis. Results: Exposure to PMMA containing the nanoparticles reduced the bacterial count by 3.2–99%, depending on the nanoparticles, bacterial types, and light conditions. Planktonic cultures of S. mutans and L. acidophilus exposed to PMMA containing 1% of TiO2/SiO2 nanoparticles showed a significant decrease (P < 0.001) (98% and 99%, respectively) in a time-dependent manner under UVA. The S. mutans and L. acidophilus counts did not significantly decrease in PMMA containing 0.5% nano-TiO2 and PMMA containing 0.5% nano-SiO2 in the dark. No statistically significant reduction (P > 0.05) was observed in the counts of S. mutans and L. acidophilus in PMMA without the nanoparticles exposed to UVA. Conclusions: PMMA resins incorporated with TiO2/SiO2 nanoparticles showed strong antimicrobial activity against the cariogenic

  6. Influence of acrylamide monomer addition to the acrylic denture-base resins on mechanical and physical properties.

    PubMed

    Aydogan Ayaz, Elif; Durkan, Rukiye

    2013-12-01

    The aim of the study was to evaluate the effect of adding acrylamide monomer (AAm) on the characterization, flexural strength, flexural modulus and thermal degradation temperature of poly(methyl methacrylate) (PMMA) denture-base resins. Specimens (n=10) were fabricated from a conventional heat-activated QC-20 (Qc-) and a microwave heat-activated Acron MC (Ac-) PMMA resins. Powder/liquid ratio followed the manufacturer's instructions for the control groups (Qc-c and Ac-c) and for the copolymer groups, the resins were prepared with 5% (-5), 10% (-10), 15% (-15) and 20% (-20) acrylamide contents, according to the molecular weight ratio, respectively. The flexural strength and flexural modulus were measured by a three-point bending test. The data obtained were statistically analyzed by Kruskal-Wallis test (α=0.05) to determine significant differences between the groups. The chemical structures of the resins were characterized by the nuclear magnetic resonance spectroscopy. Thermal stabilities were determined by thermogravimetric analysis (TGA) with a heating rate of 10 °C⋅min(-1) from 35 °C to 600 °C. Control groups from both acrylic resins showed the lowest flexural strength values. Qc-15 showed significant increase in the flexural strength when compared to Qc-c (P<0.01). Ac-10 and Ac-15 showed significance when compared to Ac-c (P<0.01). Acrylamide incorporation increased the elastic modulus in Qc-10, Qc-15 and Qc-20 when compared to Qc-c (P<0.01). Also significant increase was observed in Ac-10, Ac-15 and Ac-20 copolymer groups when compared to Ac-c (P<0.01). According to the (1)H-nuclear magnetic resonance (NMR) results, acrylamide copolymerization was confirmed in the experimental groups. TGA results showed that the thermal stability of PMMA is increased by the insertion of AAm.

  7. Influence of acrylamide monomer addition to the acrylic denture-base resins on mechanical and physical properties

    PubMed Central

    Aydogan Ayaz, Elif; Durkan, Rukiye

    2013-01-01

    The aim of the study was to evaluate the effect of adding acrylamide monomer (AAm) on the characterization, flexural strength, flexural modulus and thermal degradation temperature of poly(methyl methacrylate) (PMMA) denture-base resins. Specimens (n=10) were fabricated from a conventional heat-activated QC-20 (Qc-) and a microwave heat-activated Acron MC (Ac-) PMMA resins. Powder/liquid ratio followed the manufacturer's instructions for the control groups (Qc-c and Ac-c) and for the copolymer groups, the resins were prepared with 5% (−5), 10% (−10), 15% (−15) and 20% (−20) acrylamide contents, according to the molecular weight ratio, respectively. The flexural strength and flexural modulus were measured by a three-point bending test. The data obtained were statistically analyzed by Kruskal–Wallis test (α=0.05) to determine significant differences between the groups. The chemical structures of the resins were characterized by the nuclear magnetic resonance spectroscopy. Thermal stabilities were determined by thermogravimetric analysis (TGA) with a heating rate of 10 °C⋅min−1 from 35 °C to 600 °C. Control groups from both acrylic resins showed the lowest flexural strength values. Qc-15 showed significant increase in the flexural strength when compared to Qc-c (P<0.01). Ac-10 and Ac-15 showed significance when compared to Ac-c (P<0.01). Acrylamide incorporation increased the elastic modulus in Qc-10, Qc-15 and Qc-20 when compared to Qc-c (P<0.01). Also significant increase was observed in Ac-10, Ac-15 and Ac-20 copolymer groups when compared to Ac-c (P<0.01). According to the 1H-nuclear magnetic resonance (NMR) results, acrylamide copolymerization was confirmed in the experimental groups. TGA results showed that the thermal stability of PMMA is increased by the insertion of AAm. PMID:24030556

  8. Effects of Denture Cleansers on Heat-Polymerized Acrylic Resin: A Five-Year-Simulated Period of Use.

    PubMed

    Arruda, Carolina Noronha Ferraz; Sorgini, Danilo Balero; Oliveira, Viviane de Cássia; Macedo, Ana Paula; Lovato, Cláudia Helena Silva; Paranhos, Helena de Freitas Oliveira

    2015-01-01

    This study evaluated color stability, surface roughness and flexural strength of acrylic resin after immersion in alkaline peroxide and alkaline hypochlorite solutions, simulating a five-year-period of use. Sixty disc-shaped (16 x 4 mm) and 60 rectangular specimens (65 x 10 x 3.3 mm) were prepared from heat-polymerized acrylic resin (Lucitone 550) and assigned to 3 groups (n = 20) of immersion (20 min): C1: distilled water; AP: warm water and one alkaline peroxide tablet; SH: 0.5% NaOCl solution. Color data (∆E) were determined by a colorimeter and also quantified according to the National Bureau of Standards units. A rugosimeter was used to measure roughness (μm) and the flexural strength (MPa) was measured using a universal testing machine. Data were evaluated by Kruskal-Wallis followed by Dunn tests (color stability and surface roughness) and by one-way ANOVA and Bonferroni test (flexural strength). For all tests was considered α = 0.05. AP {0.79 (0.66;1.42)} caused color alteration significantly higher than C1 {0.45 (0.37;0.57)} and SH {0.34 (0.25;0.42)}. The mean ∆Ε values quantified by NBS were classified as "trace" for C1 (0.43) and SH (0.31) and "slight" for AP (0.96). SH {-0.015 (-0.023;0.003)} caused significantly higher ΔRa than the C1 {0.000 (-0.004;0.010)} and AP {0.000 (-0.009;0.008)} groups. There was no statistically significant difference among the solutions for flexural strength (C1: 84.62 ± 16.00, AP: 85.63 ± 12.99, SH: 84.22 ± 14.72). It was concluded that immersion in alkaline peroxide and NaOCl solutions simulating a five-year of 20 min daily soaking did not cause clinically significant adverse effects on the heat-polymerized acrylic resin.

  9. Comparative failure load values of acrylic resin denture teeth bonded to three different heat cure denture base resins: An in vitro study

    PubMed Central

    Phukela, Sumit Singh; Dua, Amit; Dua, Mahima; Sehgal, Varun; Setya, Gaurav; Dhall, Rupinder Singh

    2016-01-01

    Aim and Objectives: Acrylic teeth are used for fabrication of dentures. Debonding of tooth – denture base bond is routine problem in dental practice. The aim of this study was to comparatively evaluate failure load of acrylic resin denture teeth bonded to three different heat resin. Materials and Methods: Four groups were created out of test samples central incisors (11). Group I: Control, whereas Group II, Group III and Group IV were experimental groups modified with diatoric hole, cingulum ledge lock and Teeth modified with both diatoric hole and cingulum ledge lock, respectively. These test specimens with 3 teeth (2 central [11, 21] and 1, lateral [12] incisors) positioned imitating arrangement of teeth in the conventional denture, prepared by three different heat cure materials (DPI, Trevalon, Acralyn-H). A shear load was applied at cingulum of central incisor (11) at 130° to its long axis using universal tester at a cross head speed of 5 mm/min until failure occurred. Failure load test was conducted and statistical analysis was performed using SPSS 16 software package (IBM Company, New York, U.S). Results: Highest failure load was seen in Group IV specimens, prepared by Trevalon but did not significantly differ from that of DPI. Conclusion: The failure load of bonding denture teeth to three different heat cure materials was notably affected by modifications of ridge lap before processing. The specimens with a combination of diatoric hole and cingulum ledge lock, prepared by Trevalon showed highest failure load but did not significantly vary from that of DPI. The control group prepared by Acralyn-H showed lowest failure load but did not significantly differ from that of DPI. PMID:27195221

  10. The Effect on the Flexural Strength, Flexural Modulus and Compressive Strength of Fibre Reinforced Acrylic with That of Plain Unfilled Acrylic Resin – An in Vitro Study

    PubMed Central

    Thomas, Tony C; K, Aswini Kumar; Krishnan, Vinod; Mathew, Anil; V, Manju

    2015-01-01

    Aim: The aim of this in vitro study was to compare the flexural strength, the flexural modulus and compressive strength of the acrylic polymer reinforced with glass, carbon, polyethylene and Kevlar fibres with that of plain unfilled resin. Materials and Methods: A total of 50 specimens were prepared and divided into 10 specimens each under 5 groups namely group 1- control group without any fibres, group 2 – carbon fibres, group 3- glass fibres, group 4 – polyethylene, group 5- Kevlar. Universal testing machine (Tinius olsen, USA) was used for the testing of these specimens. Out of each group, 5 specimens were randomly selected and testing was done for flexural strength using a three point deflection test and three point bending test for compressive strength and the modulus was plotted using a graphical method. Statistical analysis was done using statistical software. Results: The respective mean values for samples in regard to their flexural strength for PMMA plain, PMMA+ glass fibre, PMMA+ carbon, PMMA+ polyethylene and PMMA+ Kevlar were 90.64, 100.79, 102.58, 94.13 and 96.43 respectively. Scheffes post hoc test clearly indicated that only mean flexural strength values of PMMA + Carbon, has the highest mean value. One-way ANOVA revealed a non-significant difference among the groups in regard to their compressive strength. Conclusion: The study concludes that carbon fibre reinforced samples has the greatest flexural strength and greatest flexural modulus, however the compressive strength remains unchanged. PMID:25954696

  11. Reduction of polyester resin shrinkage by means of epoxy resin—I. Epoxy resin modified with acids

    NASA Astrophysics Data System (ADS)

    Pietrzak, M.; Brzostowski, A.

    An attempt was made to decrease the shrinkage of unsaturated polyester resin, taking place during radiation-induced curing, by the addition of epoxy resin. In order to combine chemically both resins, the epoxy component was modified with cinnamic and acrylic acids. A composition of 90 parts of polyesster resin, 10 parts of epoxy resin modified with cinnamic acid, and 150 parts of a silica filler showed a volume shrinkage of 1.2%.

  12. Morphological alteration of microwave disinfected acrylic resins used for dental prostheses

    NASA Astrophysics Data System (ADS)

    Popescu, M. C.; Bita, B. I.; Avram, A. M.; Tucureanu, V.; Schiopu, P.

    2015-02-01

    In this paper we aim to perform a cross section morphological characterization of an acrylic polymer used for dental prostheses subjected to microwave disinfection. The method was largely investigated and the microbiological effectiveness is well established, but there are some issues regarding the in-depth alteration of the material. In our research, the surface roughness is insignificant and the samples were not polished or refined by any means. Two groups of 7 acrylic discs (20 mm diameter, 2 mm thickness) were prepared from a heat-cured powder. Half of the samples embedded a stainless steel reinforcement, in order to observe the changes at the interfaces between the polymer and metallic wire. After the gradual wet microwave treatment, the specimens - including the controls - were frozen in liquid nitrogen and broken into pieces. Fragments were selected for gold metallization to ensure a good contrast for SEM imaging. We examined the samples in cross section employing a high resolution SEM. We have observed the alterations occurred at the surface of the acrylic sample and at the interface with the metallic wire along with the increase of the power and exposure time. The bond configuration of acrylate samples was analysed by FTIR spectrometry.

  13. Effect of repair surface design, repair material, and processing method on the transverse strength of repaired acrylic denture resin.

    PubMed

    Ward, J E; Moon, P C; Levine, R A; Behrendt, C L

    1992-06-01

    The transverse strengths of blocks of denture base acrylic resin repaired with autopolymerizing monomer and polymer and autopolymerizing monomer and heat-cured polymer were measured with a three-point bending test. Three repair joints were studied: butt, round, and 45-degree bevel. Three processing methods were used: bench cure, hydroflask with hot water for 10 minutes, and hydroflask with hot water for 30 minutes. The strengths of repairs made with round and 45-degree bevel joint designs were similar and significantly greater than those with a butt joint design. The strengths of repairs processed in a hydroflask for 10 minutes and 30 minutes were similar and significantly greater than those cured on the bench top. There was no difference in the strength of repairs made with autopolymerizing monomer and polymer and autopolymerizing monomer and heat-cured polymer.

  14. Synthesis of wheat straw cellulose-g-poly (potassium acrylate)/PVA semi-IPNs superabsorbent resin.

    PubMed

    Liu, Jia; Li, Qian; Su, Yuan; Yue, Qinyan; Gao, Baoyu; Wang, Rui

    2013-04-15

    To better use wheat straw and minimize its negative impact on environment, a novel semi-interpenetrating polymer networks (semi-IPNs) superabsorbent resin (SAR) composed of wheat straw cellulose-g-poly (potassium acrylate) (WSC-g-PKA) network and linear polyvinyl alcohol (PVA) was prepared by polymerization in the presence of a redox initiating system. The structure and morphology of semi-IPNs SAR were characterized by means of FTIR, SEM and TGA, which confirmed that WSC and PVA participated in the graft polymerization reaction with acrylic acid (AA). The factors that can influence the water absorption of the semi-IPNs SAR were investigated and optimized, including the weight ratios of AA to WSC and PVA to WSC, the content of initiator and crosslinker, neutralization degree (ND) of AA, reaction temperature and time. The semi-IPNs SAR prepared under optimized synthesis condition gave the best water absorption of 266.82 g/g in distilled water and 34.32 g/g in 0.9 wt% NaCl solution. PMID:23544572

  15. Evaluation of the surface roughness of three heat-cured acrylic denture base resins with different conventional lathe polishing techniques: A comparative study

    PubMed Central

    Rao, Duggineni Chalapathi; Kalavathy, N.; Mohammad, H. S.; Hariprasad, A.; Kumar, C. Ravi

    2015-01-01

    Purpose: Surface roughness promotes adhesion and colonization of denture plaque. Therefore, it is important to know the effects of polishing and finishing on the surface roughness of various acrylic resin materials. Objectives: To evaluate and compare the effects of different conventional lathe polishing techniques on heat cured acrylic resins in producing surface roughness. Materials and Methods: Three different commercially available heat-cured acrylic resin materials namely DPI, Meliodent and Trevalon Hi were selected. 30 Specimens of each acrylic material (30 x 3 = 90, 10 x 60 x 2mm) were prepared and divided into 5 groups, each group consisted of 6 Nos. of specimens per material(6x3=18) and were grouped as Group A(unfinished), Group B (finished), Group C (Polishing Paste), Group D (Polishing Cake) and Group E (Pumice and Gold rouge). The resulted surface roughness (μm) was measured using Perthometer and observed under Scanning Electron Microscope. The values obtained were subjected statistical analyses. Results: Among the materials tested, better results were obtained with Trevalon Hi followed by Meliodent and DPI. Among the polishing methods used, superior results were obtained with universal polishing paste followed by polishing cake; Pumice and Gold rouge. Although Pumice and Gold rouge values produced greater roughness value, they were well within the threshold value of 0.2 mm. PMID:26929542

  16. Loosening torque of prosthetic screws in metal-ceramic or metal-acrylic resin implant-supported dentures with different misfit levels.

    PubMed

    Bacchi, Ataís; Paludo, Litiane; Ferraz Mesquita, Marcelo; Schuh, Christian; Federizzi, Leonardo; Oro Spazzin, Aloísio

    2013-04-26

    The aim of this study was to evaluate the effect of the prosthesis material (metal-acrylic resin or metal-ceramic) on loosening torque of the prosthetic screws in an implant-supported mandibular denture under two levels of vertical misfit. Ten frameworks were fabricated with commercially pure titanium, and five of them received acrylic resin and acrylic artificial teeth as veneering material and the other five were veneered with porcelain. Two levels of vertical fit were also created by fabricating 20 cast models to obtain four experimental groups according to the prosthesis material and misfit: Group 1 (metal-acrylic resin prosthesis with a passive fit); Group 2 (metal-acrylic resin prosthesis with a non-passive fit); Group 3 (metal-ceramic prosthesis with a passive fit); and Group 4 (metal-ceramic prosthesis with a non-passive fit). Two hundred prosthetic titanium-alloy screws were divided in 40 sets (five screws per set, n=10). After 24h, the loosening torque of the screws was evaluated using a digital torque meter. The results were submitted to two-way ANOVA analysis of variance followed by a Tukey's test (α=0.05). The mean values and standard deviations for each group were G1=7.05 (1.64), G2=5.52 (0.90), G3=6.46 (1.34), and G4=4.35 (0.99). Overall, the prosthesis material and misfit factors showed a statistically significant influence on the loosening torque (p<0.05). Metal-ceramic prosthesis and misfits decreased the loosening of the torque of the prosthetic screws.

  17. Characterization and bacterial anti-adherent effect on modified PMMA denture acrylic resin containing platinum nanoparticles

    PubMed Central

    2014-01-01

    PURPOSE This study characterized the synthesis of a modified PMMA (Polymethyl methacrylate) denture acrylic loading platinum nanoparticles (PtN) and assessed its bacterial inhibitory efficacy to produce novel antimicrobial denture base material. MATERIALS AND METHODS Polymerized PMMA denture acrylic disc (20 mm × 2 mm) specimens containing 0 (control), 10, 50, 100 and 200 mg/L of PtN were fabricated respectively. The obtained platinum-PMMA nanocomposite (PtNC) was characterized by TEM (transmission electron microscopy), SEM/EDX (scanning electron microscope/energy dispersive X-ray spectroscopy), thermogravimetric and atomic absorption spectrophotometer analysis. In antimicrobial assay, specimens were placed on the cell culture plate, and 100 µL of microbial suspensions of S. mutans (Streptococcus mutans) and S. sobrinus (Streptococcus sobrinus) were inoculated then incubated at 37℃ for 24 hours. The bacterial attachment was tested by FACS (fluorescence-activated cell sorting) analysis after staining with fluorescent probe. RESULTS PtN were successfully loaded and uniformly immobilized into PMMA denture acrylic with a proper thermal stability and similar surface morphology as compared to control. PtNC expressed significant bacterial anti-adherent effect rather than bactericidal effect above 50 mg/L PtN loaded when compared to pristine PMMA (P=.01) with no or extremely small amounts of Pt ion eluted. CONCLUSION This is the first report on the synthesis and its antibacterial activity of Pt-PMMA nanocomposite. PMMA denture acrylic loading PtN could be a possible intrinsic antimicrobial denture material with proper mechanical characteristics, meeting those specified for denture bases. For clinical application, future studies including biocompatibility, color stability and warranting the long-term effect were still required. PMID:25006385

  18. Influence of polymerization method, curing process, and length of time of storage in water on the residual methyl methacrylate content in dental acrylic resins.

    PubMed

    Bayraktar, Gulsen; Guvener, Bora; Bural, Canan; Uresin, Yagiz

    2006-02-01

    This study compared the influence of different polymerization methods (heat, auto-, and microwave energy), different curing processes (in the case of heat- and autopolymerized specimens), and length of storage of the polymerized specimens in distilled water at 37 degrees C on the residual methyl methacrylate (MMA) content in dental acrylic resin specimens. Residual MMA of 120 resin specimens were measured using high-performance liquid chromatography. For the heat-polymerized resins, the lowest residual MMA content was obtained when they were given a long-term terminal boil and then stored in the distilled water for at least 1 day. For the autopolymerized resins, the lowest residual MMA content was obtained when they were additionally cured in water at 60 degrees C and then stored in the distilled water at least 1 day. For the microwave-polymerized resins, the lowest residual MMA content was obtained when they were stored in the distilled water at least 1 month. The lowest overall residual MMA content was obtained from heat-polymerized specimens that were given a long-term terminal boil cure and then stored in the distilled water at least 1 day. Different polymerization methods and curing processes have different effects on residual MMA content. It is thus shown that storing a dental acrylic resin specimen in distilled water at 37 degrees C is a simple but effective method of reducing its residual MMA content.

  19. Investigation into the effect of use of metal primer on adhesion of heat cure acrylic resin to cast titanium: an in vitro study.

    PubMed

    Podder, Sudipto; Goel, Preeti; Kar, Sunil; Bhattacharyya, Jayanta

    2014-09-01

    The availability of adhesive primers capable of bonding chemically to base metal alloys without well defined passive oxide surface film has been improved significantly over the last decade. Therefore, the purpose of the study was to compare and evaluate the effect of metal primer on adhesion of heat cure acrylic resin to cast titanium. Shear bond strength test was conducted on 80 commercially pure titanium cast metal heat-cure acrylic resin discs treated with different surface treatments. The first group received no surface treatment (group I); the second group was subjected to sandblasting (group II); the third group was treated with bonding agent (alloy primer) (group III) and the fourth was treated with sandblasting and alloy primer (group IV). After the samples were surface treated, acrylic resin was mixed, packed and processed over the test area of cast titanium. Ten specimens of each group were immersed in distilled water for 24 h followed by thermocycling for 20,000 cycles. Shear bond-strength between the heat cure acrylic resin and titanium was evaluated using Instron universal testing machine. Debonded specimens of all the groups were subjected to SEM analysis. The bond failure (MPa) was analyzed by ANOVA and Duncan's multiple comparison tests. Surface treatment with sandblasting, followed by the application of alloy primer showed maximum shear bond strength before and after thermocycling (24.50 ± 0.59 and 17.39 ± 1.56 MPa respectively).The bond strength values are found to be in decreasing magnitudes as group IV > group III > group II > group I. The following pretreatment to improve the shear bond strength of heat cure acrylic resin to titanium is recommended in order to attain the maximum bond strength in cast titanium frameworks for various prostheses: sandblasting, cleaning in an ultrasonic bath for 10 min and air drying followed by application of a bonding agent uniformly on the sandblasted cast titanium surface before packing with heat

  20. Investigation into the effect of use of metal primer on adhesion of heat cure acrylic resin to cast titanium: an in vitro study.

    PubMed

    Podder, Sudipto; Goel, Preeti; Kar, Sunil; Bhattacharyya, Jayanta

    2014-09-01

    The availability of adhesive primers capable of bonding chemically to base metal alloys without well defined passive oxide surface film has been improved significantly over the last decade. Therefore, the purpose of the study was to compare and evaluate the effect of metal primer on adhesion of heat cure acrylic resin to cast titanium. Shear bond strength test was conducted on 80 commercially pure titanium cast metal heat-cure acrylic resin discs treated with different surface treatments. The first group received no surface treatment (group I); the second group was subjected to sandblasting (group II); the third group was treated with bonding agent (alloy primer) (group III) and the fourth was treated with sandblasting and alloy primer (group IV). After the samples were surface treated, acrylic resin was mixed, packed and processed over the test area of cast titanium. Ten specimens of each group were immersed in distilled water for 24 h followed by thermocycling for 20,000 cycles. Shear bond-strength between the heat cure acrylic resin and titanium was evaluated using Instron universal testing machine. Debonded specimens of all the groups were subjected to SEM analysis. The bond failure (MPa) was analyzed by ANOVA and Duncan's multiple comparison tests. Surface treatment with sandblasting, followed by the application of alloy primer showed maximum shear bond strength before and after thermocycling (24.50 ± 0.59 and 17.39 ± 1.56 MPa respectively).The bond strength values are found to be in decreasing magnitudes as group IV > group III > group II > group I. The following pretreatment to improve the shear bond strength of heat cure acrylic resin to titanium is recommended in order to attain the maximum bond strength in cast titanium frameworks for various prostheses: sandblasting, cleaning in an ultrasonic bath for 10 min and air drying followed by application of a bonding agent uniformly on the sandblasted cast titanium surface before packing with heat

  1. Factors affecting the bond strength of denture base and reline acrylic resins to base metal materials

    PubMed Central

    TANOUE, Naomi; MATSUDA, Yasuhiro; YANAGIDA, Hiroaki; MATSUMURA, Hideo; SAWASE, Takashi

    2013-01-01

    Objective The shear bond strengths of two hard chairside reline resin materials and an auto-polymerizing denture base resin material to cast Ti and a Co-Cr alloy treated using four conditioning methods were investigated. Material and Methods Disk specimens (diameter 10 mm and thickness 2.5 mm) were cast from pure Ti and Co-Cr alloy. The specimens were wet-ground to a final surface finish of 600 grit, air-dried, and treated with the following bonding systems: 1) air-abraded with 50-70-µm grain alumina (CON); 2) 1) + conditioned with a primer, including an acidic phosphonoacetate monomer (MHPA); 3) 1) + conditioned with a primer including a diphosphate monomer (MDP); 4) treated with a tribochemical system. Three resin materials were applied to each metal specimen. Shear bond strengths were determined before and after 10,000 thermocycles. Results The strengths decreased after thermocycling for all combinations. Among the resin materials assessed, the denture base material showed significantly (p<0.05) greater shear bond strengths than the two reline materials, except for the CON condition. After 10,000 thermocycles, the bond strengths of two reline materials decreased to less than 10 MPa for both metals. The bond strengths of the denture base material with MDP were sufficient: 34.56 MPa for cast Ti and 38.30 for Co-Cr alloy. Conclusion Bonding of reline resin materials to metals assessed was clinically insufficient, regardless of metal type, surface treatment, and resin composition. For the relining of metal denture frameworks, a denture base material should be used. PMID:24037070

  2. Investigation of flexural strength and cytotoxicity of acrylic resin copolymers by using different polymerization methods

    PubMed Central

    Ozdemir, Ali Kemal; Turgut, Mehmet; Boztug, Ali; Sumer, Zeynep

    2015-01-01

    PURPOSE The aim of this study was to appraise the some mechanical properties of polymethyl methacrylate based denture base resin polymerized by copolymerization mechanism, and to investigate the cytotoxic effect of these copolymer resins. MATERIALS AND METHODS 2-hydroxyethyl methacrylate (HEMA) and isobutyl methacrylate (IBMA) were added to monomers of conventional heat polymerized and injection-molded poly methyl methacrylate (PMMA) resin contents of 2%, 3%, and 5% by volume and polymerization was carried out. Three-point bending test was performed to detect flexural strength and the elasticity modulus of the resins. To determine the statistical differences between the study groups, the Kruskall-Wallis test was performed. Then pairwise comparisons were performed between significant groups by Mann-Whitney U test. Agar-overlay test was performed to determine cytotoxic effect of copolymer resins. Chemical analysis was determined by FTIR spectrum. RESULTS Synthesis of the copolymer was approved by FTIR spectroscopy. Within the conventional heat-polymerized group maximum transverse strength had been seen in the HEMA 2% concentration; however, when the concentration ratio increased, the strength decreased. In the injection-molded group, maximum transverse strength had been seen in the IBMA 2% concentration; also as the concentration ratio increased, the strength decreased. Only IBMA showed no cytotoxic effect at low concentrations when both two polymerization methods applied while HEMA showed cytotoxic effect in the injection-molded resins. CONCLUSION Within the limitations of this study, it may be concluded that IBMA and HEMA may be used in low concentration and at high temperature to obtain non-cytotoxic and durable copolymer structure. PMID:25932307

  3. Temporary space maintainers retained with composite resin. Part II: Fracture load in vitro.

    PubMed

    Grajower, R; Stern, N; Zamir, S T; Kohavi, D

    1981-01-01

    The average fracture load during occlusal loading of pontics which were bonded to natural abutment teeth in vitro was found to be 56.1, 57.5 and 74.2 kg for natural, acrylic resin, and Restodent pontics, respectively. Coating the roots of the abutment teeth with a thin layer of silicone rubber before embedding them in stone slightly reduced the strength of the fixed partial dentures. Thermocycling the specimens with coated roots caused a considerable decrease in strength to fracture loads of 33.0, 17.9, and 37.3 kg for natural, acrylic resin, and Restodent pontics, respectively. Fracture of the enamel of natural tooth pontics was observed in a few specimens. The superior strength of the fixed partial dentures with natural tooth and Restodent pontics would indicate that these pontics are superior for clinical trials rather than acrylic resin pontics.

  4. The effect of acrylic latex-based polymer on cow blood adhesive resins for wood composites

    NASA Astrophysics Data System (ADS)

    Yan, J.; Lin, H. L.; Feng, G. Z.; Gunasekaran, S.

    2016-07-01

    In this paper, alkali-modified cow blood adhesive (BA) and blood adhesive/acrylic latex-based adhesive (BA/ALB) were prepared. The physicochemical and adhesion properties of cow blood adhesive such as UV- visible spectra, particle size, viscosity were evaluated; share strength, water resistance were tested. UV- visible spectra indicates that the strong bonding strength of BA/ALB appeared after incorporating; the particle size of adhesive decreased with the increase of ALB concentration, by mixing ALB and BA, hydrophilic polymer tends locate or extand the protein chains and provide stability of the particles; viscosity decreased as shear rate increased in concordance with a pseudoplastic behavior; both at dry and soak conditions, BA and ALB/BA show significant difference changes when mass fraction of ALB in blend adhesive was over 30% (p < 0.05). ALB/ BA (ALB30%) is not significant different than that of phenol formaldehyde which was used as control. A combination of cow blood and acrylic latex-based adhesive significantly increased the strength and water resistance of the resulting wood.

  5. The pH effect of solvent in silanization on fluoride released and mechanical properties of heat-cured acrylic resin containing fluoride-releasing filler.

    PubMed

    Nakornchai, Natha; Arksornnukit, Mansuang; Kamonkhantikul, Krid; Takahashi, Hidekazu

    2016-01-01

    This study aimed to evaluate the effect of an acidic-adjusted pH of solvent in silanization on the amount of fluoride released and mechanical properties of heat-cured acrylic resin containing a silanized fluoride-releasing filler. The experimental groups were divided into 4 groups; non-silanized, acidic-adjusted pH, non-adjusted pH, and no filler as control. For fluoride measurement, each specimen was placed in deionized water which was changed every day for 7 days, every week for 7 weeks and measured. The flexural strength and flexural modulus were evaluated after aging for 48 h, 1, and 2 months. Two-way ANOVA indicated significant differences among groups, storage times, and its interaction in fluoride measurement and flexural modulus. For flexural strength, there was significant difference only among groups. Acidic-adjusted pH of solvent in silanization enhanced the amount of fluoride released from acrylic resin, while non-adjusted pH of solvent exhibited better flexural strength of acrylic resin. PMID:27252000

  6. The pH effect of solvent in silanization on fluoride released and mechanical properties of heat-cured acrylic resin containing fluoride-releasing filler.

    PubMed

    Nakornchai, Natha; Arksornnukit, Mansuang; Kamonkhantikul, Krid; Takahashi, Hidekazu

    2016-01-01

    This study aimed to evaluate the effect of an acidic-adjusted pH of solvent in silanization on the amount of fluoride released and mechanical properties of heat-cured acrylic resin containing a silanized fluoride-releasing filler. The experimental groups were divided into 4 groups; non-silanized, acidic-adjusted pH, non-adjusted pH, and no filler as control. For fluoride measurement, each specimen was placed in deionized water which was changed every day for 7 days, every week for 7 weeks and measured. The flexural strength and flexural modulus were evaluated after aging for 48 h, 1, and 2 months. Two-way ANOVA indicated significant differences among groups, storage times, and its interaction in fluoride measurement and flexural modulus. For flexural strength, there was significant difference only among groups. Acidic-adjusted pH of solvent in silanization enhanced the amount of fluoride released from acrylic resin, while non-adjusted pH of solvent exhibited better flexural strength of acrylic resin.

  7. Effect of cleanser solutions on the color of acrylic resins associated with titanium and nickel-chromium alloys.

    PubMed

    Freitas Oliveira Paranhos, Helena de; Bezzon, Osvaldo Luiz; Davi, Letícia Resende; Felipucci, Daniela Nair Borges; Silva, Cláudia Helena Lovato da; Pagnano, Valéria Oliveira

    2014-01-01

    This study evaluated the effect of cleanser solutions on the color of heat-polymerized acrylic resin (HPAR) and on the brightness of dental alloys with 180 immersion trials. Disk-shaped specimens were made with I) commercially pure titanium, II) nickel-chromium-molybdenum-titanium, III) nickel-chromium molybdenum, and IV) nickel-chromium-molybdenum beryllium. Each cast disk was invested in the flasks, incorporating the metal disk into the HPAR. The specimens (n=5) were then immersed in solutions containing: 0.05% sodium hypochlorite, 0.12% chlorhexidine digluconate, 0.500 mg cetylpyridinium chloride, a citric acid tablet, one of two different sodium perborate/enzyme tablets, and water. The color measurements (∆E) of the HPAR were determined by a colorimeter in accordance with the National Bureau of Standards. The surface brightness of the metal was visually examined for the presence of tarnish. The results (ANOVA; Tukey test-α=0.05) show that there was a significant difference between the groups (p<0.001) but not among the solutions (p=0.273). The highest mean was obtained for group III (5.06), followed by group II (2.14). The lowest averages were obtained for groups I (1.33) and IV (1.35). The color changes in groups I, II and IV were slight but noticeable, and the color change was considerable for group III. The visual analysis showed that 0.05% sodium hypochlorite caused metallic brightness changes in groups II and IV. It can be concluded that the agents had the same effect on the color of the resin and that the metallic alloys are not resistant to the action of 0.05% sodium hypochlorite.

  8. Resin glycosides from the aerial parts of Operculina turpethum.

    PubMed

    Ding, Wenbing; Jiang, Zi-Hua; Wu, Ping; Xu, Liangxiong; Wei, Xiaoyi

    2012-09-01

    Three glycosidic acids, turpethic acids A-C, and two intact resin glycosides, turpethosides A and B, all having a common pentasaccharide moiety and 12-hydroxy fatty acid aglycones of different chain lengths, were obtained from the aerial parts of Operculina turpethum. Their structures were elucidated by spectroscopic analyses and chemical correlations. The aglycones were characterized as 12-hydroxypentadecanoic acid in two compounds, 12-hydroxyhexadecanoic acid in two other components, and 12-hydroxyheptadecanoic acid in the fifth compound, which were all confirmed by synthesis. The absolute configurations of these aglycones were all established as S by Mosher's method. These compounds represent the first examples of resin glycosides with a monohydroxylated 12-hydroxy fatty acid as an aglycone, and one compound is the first described resin glycoside having a hydroxylated C(17) fatty acid as its aglycone.

  9. The effect of joint surface contours and glass fiber reinforcement on the transverse strength of repaired acrylic resin: An in vitro study

    PubMed Central

    Anasane, Nayana; Ahirrao, Yogesh; Chitnis, Deepa; Meshram, Suresh

    2013-01-01

    Background: Denture fracture is an unresolved problem in complete denture prosthodontics. However, the repaired denture often experiences a refracture at the repaired site due to poor transverse strength. Hence, this study was conducted to evaluate the effect of joint surface contours and glass fiber reinforcement on the transverse strength of repaired acrylic resins. Materials and Methods: A total of 135 specimens of heat polymerized polymethyl methacrylate resin of dimensions 64 × 10 × 2.5 mm were fabricated. Fifteen intact specimens served as the control and 120 test specimens were divided into four groups (30 specimens each), depending upon the joint surface contour (butt, bevel, rabbet and round), with two subgroups based on type of the repair. Half of the specimens were repaired with plain repair resin and the other half with glass fibers reinforced repair resin. Transverse strength of the specimens was determined using three-point bending test. The results were analyzed using one-way ANOVA and Tukey post-hoc test (α= 0.05). Results: Transverse strength values for all repaired groups were significantly lower than those for the control group (P < 0.001) (88.77 MPa), with exception of round surface design repaired with glass fiber reinforced repair resin (89.92 MPa) which was significantly superior to the other joint surface contours (P < 0.001). Glass fiber reinforced resin significantly improved the repaired denture base resins as compared to the plain repair resin (P < 0.001). Conclusion: Specimens repaired with glass fiber reinforced resin and round surface design exhibited highest transverse strength; hence, it can be advocated for repair of denture base resins. PMID:23946739

  10. Ethanol Postpolymerization Treatment for Improving the Biocompatibility of Acrylic Reline Resins

    PubMed Central

    Neves, Cristina B.; Lopes, Luís P.; Ferrão, Helena F.; Miranda, Joana P.; Castro, Matilde F.; Bettencourt, Ana F.

    2013-01-01

    Objective. To evaluate the effect of postpolymerization treatment based on ethanol-aqueous solutions on the residual monomer (RM) content, flexural strength, microhardness, and cytotoxicity of hard chairside reline resins (Kooliner, Ufi Gel Hard). Methods. After polymerization, specimens were immersed in water, 20%, 50%, or 70% ethanol solutions at 23°C or 55°C for 10 minutes. Controls were left untreated. HPLC was used for the determination of RM content. Specimens were submitted to Vickers microhardness and 3-point loading flexural strength tests. Cytotoxicity of resin eluates was determined on human fibroblasts by assessing cellular mitochondrial function and lactate dehydrogenase release. Results. Higher concentrations of ethanol promoted lower RM content at 55°C in both materials. The mechanical properties were maintained after 50% and 20% ethanol treatments in Kooliner and Ufi Gel Hard, respectively. Specimens submitted to those treatments showed significant reduction on cytotoxicity compared to immersion in hot water, the treatment of choice in the recent literature. Significance. Immersion of relined dentures in specific ethanol solutions at 55°C for 10 minutes can be considered an effective postpolymerization treatment contributing to increase materials biocompatibility. The proposed protocol is expeditious and easy to achieve with simple equipment in a dental office. PMID:23971038

  11. Custom Metal Occlusal Surface for Acrylic Resin Denture Teeth to Enhance Wear Resistance: A Case Report

    PubMed Central

    Shivji, Rizwan Ali; Kamble, Vaibhav D.; Khan, Mohd. Atif

    2012-01-01

    Wear of the occlusal surface of the denture is a known fact which leads to subsequent changes in jaw relation, vertical dimension, loss of aesthetics, aged looks, and decrease in masticatory efficiency. Treatment modalities includes, change of denture set after a regular interval of 4-5 years, use of wear resistant denture teeth that includes wear resistant resin or porcelain teeth, teeth with cast metal occlusal surface, and altering occlusal contact areas of denture teeth by use of silver amalgam fillings. A case report of a patient who had increased tendency of occlusal wear was treated with custom made metal occlusal surface of denture teeth to enhance wear resistance and to improve the masticatory efficiency. PMID:22997592

  12. Comparative evaluation of different mechanical modifications of denture teeth on bond strength between high-impact acrylic resin and denture teeth: An in vitro study

    PubMed Central

    Phukela, Sumit Singh; Chintalapudi, Siddesh Kumar; Sachdeva, Harleen; Dhall, Rupinder Singh; Sharma, Neeraj; Prabhu, Allama

    2016-01-01

    Aim and Objective: Acrylic teeth separates from the denture base and remains a major worry in day-to-day routine dental procedure. The present study was conducted to comparatively evaluate different mechanical modifications of acrylic teeth on bond strength between Lucitone 199 heat cure resin and cross-linked teeth. Materials and Methods: The test specimens, central incisors (21) were demarcated into four groups. Group 1 was the control group, whereas Group 2, Group 3, and Group 4 were experimental groups modified with round groove, vertical groove, and T-shaped groove, respectively. The preparation of masterpiece was done by aligning the long axis of the central incisor teeth at 45° to the base of a wax block (8 mm × 10 mm × 30 mm), with ridge lap surface contacting the base. These test specimen (21) was prepared by Lucitone 199 heat cure resin. Evaluation of bond strength of all the specimens was done using universal tester (materials testing machine). Shapiro–Wilk Test, one-way analysis of variance (ANOVA), and Bonferroni test were done to do statistical investigation. Results: Group 1 specimens prepared by Lucitone 199 heat cure resin showed the lowest bond strength and Group 4 specimens prepared with T-shaped groove packed with Lucitone 199 exhibited the highest bond strength. Conclusion: The bond strength between Lucitone 199 heat cure resin and cross-linked teeth was increased when mechanical modifications was done on denture teeth. The specimens prepared with T-shaped groove packed with Lucitone 199 heat cure resin showed the highest bond strength followed by Group 3, Group 2, and lastly Group 1 prepared by Lucitone 199 heat cure resin. PMID:27114957

  13. Surface properties of multilayered, acrylic resin artificial teeth after immersion in staining beverages

    PubMed Central

    NEPPELENBROEK, Karin Hermana; KUROISHI, Eduardo; HOTTA, Juliana; MARQUES, Vinicius Rizzo; MOFFA, Eduardo Buozi; SOARES, Simone; URBAN, Vanessa Migliorini

    2015-01-01

    Objective To evaluate the effect of staining beverages (coffee, orange juice, and red wine) on the Vickers hardness and surface roughness of the base (BL) and enamel (EL) layers of improved artificial teeth (Vivodent and Trilux). Material and Methods Specimens (n=8) were stored in distilled water at 37°C for 24 h and then submitted to the tests. Afterwards, specimens were immersed in one of the staining solutions or distilled water (control) at 37°C, and the tests were also performed after 15 and 30 days of immersion. Data were analyzed using 3-way ANOVA and Tukey’s test (α=0.05). Results Vivodent teeth exhibited a continuous decrease (p<0.0005) in hardness of both layers for up to 30 days of immersion in all solutions. For Trilux teeth, similar results were found for the EL (p<0.004), and the BL showed a decrease in hardness after 15 days of immersion (p<0.01). At the end of 30 days, this reduction was not observed for coffee and water (p>0.15), but red wine and orange juice continuously reduced hardness values (p<0.0004). Red wine caused the most significant hardness changes, followed by orange juice, coffee, and water (p<0.006). No significant differences in roughness were observed for both layers of the teeth during the immersion period, despite the beverage (p>0.06). Conclusions Hardness of the two brands of acrylic teeth was reduced by all staining beverages, mainly for red wine. Roughness of both layers of the teeth was not affected by long-term immersion in the beverages. PMID:26398509

  14. Effects of Laboratory Disinfecting Agents on Dimensional Stability of Three Commercially Available Heat-Cured Denture Acrylic Resins in India: An In-Vitro Study

    PubMed Central

    Jujare, Ravikanth Haridas; Varghese, Rana Kalappattil; Singh, Vishwa Deepak; Gaurav, Amit

    2016-01-01

    Introduction Dental professionals are exposed to a wide variety of microorganisms which calls for use of effective infection control procedures in the dental office and laboratories that can prevent cross-contamination that could extend to dentists, dental office staff, dental technicians as well as patients. This concern has led to a renewed interest in denture sterilization and disinfection. Heat polymerized dentures exhibit dimensional change during disinfection procedure. Aim The purpose of this study was to determine the influence of different types of widely used laboratory disinfecting agents on the dimensional stability of heat-cured denture acrylic resins and to compare the dimensional stability of three commercially available heat-cured denture acrylic resins in India. Materials and Methods Twelve specimens of uniform dimension each of three different brands namely Stellon, Trevalon and Acralyn-H were prepared using circular metal disc. Chemical disinfectants namely 2% alkaline glutaraldehyde, 1% povidone-iodine, 0.5% sodium hypochlorite and water as control group were used. Diameter of each specimen was measured before immersion and after immersion with time interval of 1 hour and 12 hours. The data was evaluated statistically using one way analysis of variance. Results All the specimens in three disinfectants and in water exhibited very small amount of linear expansion. Among three disinfectants, specimens in 2% alkaline glutaraldehyde exhibited least(0.005mm) and water showed highest (0.009mm) amount of dimensional change. Among resins, Trevalon showed least (0.067mm) and Acralyn-H exhibited highest (0.110mm) amount of dimensional change. Conclusion Although, all the specimens of three different brands of heat-cured denture acrylic resins exhibited increase in linear dimensional change in all the disinfectants and water, they were found to be statistically insignificant. PMID:27134996

  15. In vitro evaluation of adherence of Candida albicans, Candida glabrata, and Streptococcus mutans to an acrylic resin modified by experimental coatings.

    PubMed

    Izumida, Fernanda Emiko; Moffa, Eduardo Buozi; Vergani, Carlos Eduardo; Machado, Ana Lúcia; Jorge, Janaína Habib; Giampaolo, Eunice Teresinha

    2014-01-01

    This study evaluated the effect of experimental coatings, containing zwitterion or hydrophilic monomers, on the adherence of Candida albicans, Candida glabrata, and Streptococcus mutans to an acrylic resin. Acrylic samples (smooth or rough surfaces) were left untreated (control) or coated with one of the following experimental coatings: 3-hydroxypropylmethacrylate (HP) or sulfobetaine methacrylate (S), at concentrations of 25, 30, or 35%. Half of the specimens were coated with saliva. The adhesion test was performed by incubating specimens in C. albicans, C. glabrata, and S. mutans suspensions at 37°C for 90 min. The number of adhered microorganisms was determined by metabolic activity (XTT) and by cell viability (CFU). All coated specimens exhibited lower absorbance and CFU values compared to control specimens. Saliva and roughness did not promote microorganism adherence. An XPS analysis confirmed the modification in the chemical composition of the coatings in the experimental samples. These experimental coatings significantly reduced the adherence of C. albicans, C. glabrata and S. mutans to acrylic resin.

  16. To evaluate and compare the porosities in the acrylic mandibular denture bases processed by two different polymerization techniques, using two different brands of commercially available denture base resins - an in vitro study

    PubMed Central

    Kasina, Sitaram Prasad; Ajaz, Tarannum; Attili, Sirisha; Surapaneni, Hemchand; Cherukuri, Muralikrishna; Srinath, H P

    2014-01-01

    Background: The aim of this study was to evaluate and compare the porosities in the mandibular acrylic denture bases processed by heat and microwave polymerization techniques, using two different brands of commercially available denture base resins. Materials & Methods: Two brands of heat activated denture base resins, DPI plain and Acralyn H cross linked denture base resins designed for conventional water bath polymerization, were used to prepare 48 test specimens of mandibular acrylic denture bases. The test specimens were processed using one cycle of conventional water bath polymerization and one cycle of microwave polymerization. The absolute density of acrylic resin was used to calculate the percent mean porosity of each mandibular acrylic denture base by use of various equations. Results: Anova analysis reveals highly significant difference between mean percent porosity values of whole denture bases of all groups. Statistics reveals that heat polymerized groups have lesser mean percent porosity values than microwave polymerized groups. It also reveals that denture bases processed with Acralyn H cross linked denture base resin have lesser mean percent porosity values than denture bases processed with DPI Plain denture base resin. Conclusion: Specimens processed with Acralyn H cross linked denture base resin by conventional heat polymerization technique has the least mean percent porosity and specimens processed with DPI Plain denture base resin by microwave polymerization technique has the highest mean percent porosity. How to cite the article: Kasina SP, Ajaz T, Attili S, Surapaneni H, Cherukuri M, Srinath HP. To evaluate and compare the porosities in the acrylic mandibular denture bases processed by two different polymerization techniques, using two different brands of commercially available denture base resins - an in vitro study. J Int Oral Health 2014;6(1):72-7. PMID:24653607

  17. Toughening mechanism in elastomer-modified epoxy resins, part 2

    NASA Technical Reports Server (NTRS)

    Yee, A. F.; Pearson, R. A.

    1984-01-01

    The role of matrix ductility on the toughenability and toughening mechanism of elastomer-modified DGEBRA epoxies was investigated. Matrix ductility was varied by using epoxide resins of varying epoxide monomer molecular weights. These epoxide resins were cured using 4,4' diaminodiphenyl sulfone (DDS) and, in some cases, modified with 10% HYCAR(r)CTBN 1300X8. Fracture roughness values for the neat epoxies were found to be almost independent on the monomer molecular weight of the epoxide resin used. However, it was found that the fracture toughness of the elastomer-modified epoxies was very dependent upon the epoxide monomer molecular weight. Tensile dilatometry indicated that the toughening mechanism, when present, is similar to the mechanisms found for the piperidine cured epoxies in Part 1. SEM and OM corroborate this finding. Dynamic mechanical studies were conducted to shed light on the toughenability of the epoxies. The time-dependent small strain behavior of these epoxies were separated into their bulk and shear components. The bulk component is related to brittle fracture, whereas the shear component is related to yielding. It can be shown that the rates of shear and bulk strain energy buildup for a given stress are uniquely determined by the values of Poisson's ratio, nu. It was found that nu increases as the monomer molecular weight of the epoxide resin used increases. This increase in nu can be associated with the low temperature beta relaxation. The effect of increasing cross-link density is to shift the beta relaxation to higher temperatures and to decrease the magnitude of the beta relaxation. Thus, increasing cross-link density decreases nu and increases the tendency towards brittle fracture.

  18. Safety and Tolerability of Essential Oil from Cinnamomum zeylanicum Blume Leaves with Action on Oral Candidosis and Its Effect on the Physical Properties of the Acrylic Resin.

    PubMed

    Oliveira, Julyana de Araújo; da Silva, Ingrid Carla Guedes; Trindade, Leonardo Antunes; Lima, Edeltrudes Oliveira; Carlo, Hugo Lemes; Cavalcanti, Alessandro Leite; de Castro, Ricardo Dias

    2014-01-01

    The anti-Candida activity of essential oil from Cinnamomum zeylanicum Blume, as well as its effect on the roughness and hardness of the acrylic resin used in dental prostheses, was assessed. The safety and tolerability of the test product were assessed through a phase I clinical trial involving users of removable dentures. Minimum inhibitory concentration (MIC) and minimum fungicidal concentrations (MFC) were determined against twelve Candida strains. Acrylic resin specimens were exposed to artificial saliva (GI), C. zeylanicum (GII), and nystatin (GIII) for 15 days. Data were submitted to ANOVA and Tukey posttest (α = 5%). For the phase I clinical trial, 15 healthy patients used solution of C. zeylanicum at MIC (15 days, 3 times a day) and were submitted to clinical and mycological examinations. C. zeylanicum showed anti-Candida activity, with MIC = 625.0 µg/mL being equivalent to MFC. Nystatin caused greater increase in roughness and decreased the hardness of the material (P < 0.0001), with no significant differences between GI and GII. As regards the clinical trial, no adverse clinical signs were observed after intervention. The substance tested had a satisfactory level of safety and tolerability, supporting new advances involving the clinical use of essential oil from C. zeylanicum.

  19. Safety and Tolerability of Essential Oil from Cinnamomum zeylanicum Blume Leaves with Action on Oral Candidosis and Its Effect on the Physical Properties of the Acrylic Resin

    PubMed Central

    Oliveira, Julyana de Araújo; da Silva, Ingrid Carla Guedes; Trindade, Leonardo Antunes; Lima, Edeltrudes Oliveira; Carlo, Hugo Lemes; Cavalcanti, Alessandro Leite; de Castro, Ricardo Dias

    2014-01-01

    The anti-Candida activity of essential oil from Cinnamomum zeylanicum Blume, as well as its effect on the roughness and hardness of the acrylic resin used in dental prostheses, was assessed. The safety and tolerability of the test product were assessed through a phase I clinical trial involving users of removable dentures. Minimum inhibitory concentration (MIC) and minimum fungicidal concentrations (MFC) were determined against twelve Candida strains. Acrylic resin specimens were exposed to artificial saliva (GI), C. zeylanicum (GII), and nystatin (GIII) for 15 days. Data were submitted to ANOVA and Tukey posttest (α = 5%). For the phase I clinical trial, 15 healthy patients used solution of C. zeylanicum at MIC (15 days, 3 times a day) and were submitted to clinical and mycological examinations. C. zeylanicum showed anti-Candida activity, with MIC = 625.0 µg/mL being equivalent to MFC. Nystatin caused greater increase in roughness and decreased the hardness of the material (P < 0.0001), with no significant differences between GI and GII. As regards the clinical trial, no adverse clinical signs were observed after intervention. The substance tested had a satisfactory level of safety and tolerability, supporting new advances involving the clinical use of essential oil from C. zeylanicum. PMID:25574178

  20. Effect of nonthermal plasma treatment on surface chemistry of commercially-pure titanium and shear bond strength to autopolymerizing acrylic resin.

    PubMed

    Vechiato-Filho, Aljomar José; da Silva Vieira Marques, Isabella; dos Santos, Daniela Micheline; Matos, Adaias Oliveira; Rangel, Elidiane Cipriano; da Cruz, Nilson Cristino; Barão, Valentim Adelino Ricardo

    2016-03-01

    The effect of nonthermal plasma on the surface characteristics of commercially pure titanium (cp-Ti), and on the shear bond strength between an autopolymerizing acrylic resin and cp-Ti was investigated. A total of 96 discs of cp-Ti were distributed into four groups (n=24): Po (no surface treatment), SB (sandblasting), Po+NTP and SB+NTP (methane plasma). Surface characterization was performed through surface energy, surface roughness, scanning microscopy, energy dispersive spectroscopy, and X-ray diffraction tests. Shear bond strength test was conducted immediately and after thermocycling. Surface treatment affected the surface energy and roughness of cp-Ti discs (P<.001). SEM-EDS showed the presence of the carbide thin film. XRD spectra revealed no crystalline phase changes. The SB+NTP group showed the highest bond strength values (6.76±0.70 MPa). Thermocycling reduced the bond strength of the acrylic resin/cp-Ti interface (P<.05), except for Po group. NTP is an effective treatment option for improving the shear bond strength between both materials. PMID:26706504

  1. Effect of nonthermal plasma treatment on surface chemistry of commercially-pure titanium and shear bond strength to autopolymerizing acrylic resin.

    PubMed

    Vechiato-Filho, Aljomar José; da Silva Vieira Marques, Isabella; dos Santos, Daniela Micheline; Matos, Adaias Oliveira; Rangel, Elidiane Cipriano; da Cruz, Nilson Cristino; Barão, Valentim Adelino Ricardo

    2016-03-01

    The effect of nonthermal plasma on the surface characteristics of commercially pure titanium (cp-Ti), and on the shear bond strength between an autopolymerizing acrylic resin and cp-Ti was investigated. A total of 96 discs of cp-Ti were distributed into four groups (n=24): Po (no surface treatment), SB (sandblasting), Po+NTP and SB+NTP (methane plasma). Surface characterization was performed through surface energy, surface roughness, scanning microscopy, energy dispersive spectroscopy, and X-ray diffraction tests. Shear bond strength test was conducted immediately and after thermocycling. Surface treatment affected the surface energy and roughness of cp-Ti discs (P<.001). SEM-EDS showed the presence of the carbide thin film. XRD spectra revealed no crystalline phase changes. The SB+NTP group showed the highest bond strength values (6.76±0.70 MPa). Thermocycling reduced the bond strength of the acrylic resin/cp-Ti interface (P<.05), except for Po group. NTP is an effective treatment option for improving the shear bond strength between both materials.

  2. Effect of sodium hypochlorite and peracetic acid on the surface roughness of acrylic resin polymerized by heated water for short and long cycles

    PubMed Central

    Sczepanski, Felipe; Sczepanski, Claudia Roberta Brunnquell; Berger, Sandrine Bittencourt; Consani, Rafael Leonardo Xediek; Gonini-Júnior, Alcides; Guiraldo, Ricardo Danil

    2014-01-01

    Objective: To evaluate the surface roughness of acrylic resin submitted to chemical disinfection via 1% sodium hypochlorite (NaClO) or 1% peracetic acid (C2H4O3). Materials and Methods: The disc-shaped resin specimens (30 mm diameter ×4 mm height) were polymerized by heated water using two cycles (short cycle: 1 h at 74°C and 30 min at 100°C; conventional long cycle: 9 h at 74°C). The release of substances by these specimens in water solution was also quantified. Specimens were fabricated, divided into four groups (n = 10) depending on the polymerization time and disinfectant. After polishing, the specimens were stored in distilled deionized water. Specimens were immersed in 1% NaClO or 1% C2H4O3 for 30 min, and then were immersed in distilled deionized water for 20 min. The release of C2H4O3 and NaClO was measured via visual colorimetric analysis. Roughness was measured before and after disinfection. Roughness data were subjected to two-way ANOVA and Tukey's test. Results: There was no interaction between polymerization time and disinfectant in influencing the average surface roughness (Ra, P = 0.957). Considering these factors independently, there were significant differences between short and conventional long cycles (P = 0.012), but no significant difference between the disinfectants hypochlorite and C2H4O3 (P = 0.366). Visual colorimetric analysis did not detect release of substances. Conclusion: It was concluded that there was the difference in surface roughness between short and conventional long cycles, and disinfection at acrylic resins polymerized by heated water using a short cycle modified the properties of roughness. PMID:25512737

  3. In Vitro Comparison of Compressive and Tensile Strengths ofAcrylic Resins Reinforced by Silver Nanoparticles at 2% and0.2% Concentrations

    PubMed Central

    Ghaffari, Tahereh; Hamedirad, Fahimeh; Ezzati, Baharak

    2014-01-01

    Background and aims. Polymethyl methacrylate, PMMA, is widely used in prosthodontics for fabrication of removable prostheses. This study was undertaken to investigate the effect of adding silver nanoparticles (AgNPs) to PMMA at 2% and 0.2% concentrations on compressive and tensile strengths of PMMA. Materials and methods. The silver nanoparticles were mixed with heat-cured acrylic resin in an amalgamator in two groups at 0.2 and 2 wt% of AgNPs. Eighteen 2×20×200-mm samples were prepared for tensile strength test, 12 samples containing silver nanoparticle and 6 samples for the control group. Another 18 cylindrical 25×38-mm samples were prepared for compressive strength test. Scanning electron microscopy was used to verify homogeneous distribution of particles. The powder was manually mixed with a resin monomer and then the mixture was properly blended. Before curing, the paste was packed into steel molds. After curing, the specimens were removed from the molds. One-way ANOVA was used for statistical analysis, followed by multiple comparison test (Scheffé’s test). Results. This study showed that the mean compressive strength of PMMA reinforced with AgNPs was significantly higher than that of the unmodified PMMA (P<0.05). It was not statistically different between the two groups reinforced with AgNPs. The tensile strength was not significantly different between the 0.2% group and unmodified PMMA and it de-creased significantly after incorporation of 2% AgNPs (P<0.05). Conclusion. Based on the results and the desirable effect of nanoparticles of silver on improvement of compressive strength of PMMA, use of this material with proper concentration in the palatal area of maxillary acrylic resin dentures is recommended. PMID:25587381

  4. Argon Ion Laser Polymerized Acrylic Resin: A Comparative Analysis of Mechanical Properties of Laser Cured, Light Cured and Heat Cured Denture Base Resins

    PubMed Central

    Murthy, S Srinivasa; Murthy, Gargi S

    2015-01-01

    Background: Dentistry in general and prosthodontics in particular is evolving at greater pace, but the denture base resins poly methyl methacrylate. There has been vast development in modifying chemically and the polymerization techniques for better manipulation and enhancement of mechanical properties. One such invention was introduction of visible light cure (VLC) denture base resin. Argon ion lasers have been used extensively in dentistry, studies has shown that it can polymerize restorative composite resins. Since composite resin and VLC resin share the same photo initiator, Argon laser is tested as activator for polymerizing VLC resin. In the Phase 1 study, the VLC resin was evaluated for exposure time for optimum polymerization using argon ion laser and in Phase 2; flexural strength, impact strength, surface hardness and surface characteristics of laser cured resin was compared with light cure and conventional heat cure resin. Materials and Methods: Phase 1; In compliance with American Dental Association (ADA) specification no. 12, 80 samples were prepared with 10 each for different curing time using argon laser and evaluated for flexural strength on three point bend test. Results were compared to established performance requirement specified. Phase 2, 10 specimen for each of the mechanical properties (30 specimen) were polymerized using laser, visible light and heat and compared. Surface and fractured surface of laser, light and heat cured resins were examined under scanning electron microscope (SEM). Results: In Phase 1, the specimen cured for 7, 8, 9 and 10 min fulfilled ADA requirement. 8 min was taken as suitable curing time for laser curing. Phase 2 the values of mechanical properties were computed and subjected to statistical analysis using one-way ANOVA and Tukey post-hoc test. The means of three independent groups showed significant differences between any two groups (P < 0.001). Conclusion: Triad VLC resin can be polymerized by argon ion laser with

  5. Effect of leaching residual methyl methacrylate concentrations on in vitro cytotoxicity of heat polymerized denture base acrylic resin processed with different polymerization cycles

    PubMed Central

    BURAL, Canan; AKTAŞ, Esin; DENIZ, Günnur; ÜNLÜÇERÇI, Yeşim; BAYRAKTAR, Gülsen

    2011-01-01

    Objectives Residual methyl methacrylate (MMA) may leach from the acrylic resin denture bases and have adverse effects on the oral mucosa. This in vitro study evaluated and correlated the effect of the leaching residual MMA concentrations ([MMA]r) on in vitro cytotoxicity of L-929 fibroblasts. Material and Methods A total of 144 heat-polymerized acrylic resin specimens were fabricated using 4 different polymerization cycles: (1) at 74ºC for 9 h, (2) at 74ºC for 9 h and terminal boiling (at 100ºC) for 30 min, (3) at 74ºC for 9 h and terminal boiling for 3 h, (4) at 74ºC for 30 min and terminal boiling for 30 min. Specimens were eluted in a complete cell culture medium at 37ºC for 1, 2, 5 and 7 days. [MMA]r in eluates was measured using high-performance liquid chromatography. In vitro cytotoxicity of eluates on L-929 fibroblasts was evaluated by means of cell proliferation using a tetrazolium salt XTT (sodium 3´-[1-phenyl-aminocarbonyl)-3,4-tetrazolium]bis(4-methoxy-6-nitro)benzenesulphonic acid) assay. Differences in [MMA]r of eluates and cell proliferation values between polymerization cycles were statistically analyzed by Kruskal-Wallis, Friedman and Dunn's multiple comparison tests. The correlation between [MMA]r of eluates and cell proliferation was analyzed by Pearson's correlation test (p<0.05). Results [MMA]r was significantly (p≤0.001) higher in eluates of specimens polymerized with cycle without terminal boiling after elution of 1 and 2 days. Cell proliferation values for all cycles were significantly (p<0.01) lower in eluates of 1 day than those of 2 days. The correlation between [MMA]r and cell proliferation values was negative after all elution periods, showing significance (p<0.05) for elution of 1 and 2 days. MMA continued to leach from acrylic resin throughout 7 days and leaching concentrations markedly reduced after elution of 1 and 2 days. Conclusion Due to reduction of leaching residual MMA concentrations, use of terminal boiling in the

  6. Clinical applications of visible light-cured resin in maxillofacial prosthetics. Part I: Denture base and reline material.

    PubMed

    Shifman, A

    1990-11-01

    A visible light-cured resin system enables the dentist to accomplish chairside relining of removable prosthesis. The material is pliable and can be initially cured in the mouth with the regular hand-held visible light. A special unit is needed to completely cure the material, which thereafter is comparable in quality to heat-polymerized acrylic resin. The value of this system for the practice of maxillofacial prosthetics is demonstrated by the ease of relining of various devices and obturator prostheses.

  7. Effect of different palatal vault shapes on the dimensional stability of glass fiber-reinforced heat-polymerized acrylic resin denture base material

    PubMed Central

    Dalkiz, Mehmet; Arslan, Demet; Tuncdemir, Ali Riza; Bilgin, M.Selim; Aykul, Halil

    2012-01-01

    Objective: The aim of this study was to determine the effect of different palatal vault shapes on the dimensional stability of a glass fiber reinforced heat polymerized acrylic resin denture base material. Methods: Three edentulous maxilla with shallow, deep and medium shaped palatal vaults were selected and elastomeric impressions were obtained. A maxillary cast with four reference points (A, B, C, and D) was prepared to serve as control. Point (A) was marked in the anterior midline of the edentulous ridge in the incisive papillary region, points (B) and (C) were marked in the right and left posterior midlines of the edentulous ridge in the second molar regions, and point (D) was marked in the posterior palatal midline near the fovea palatina media (Figure 2). To determine linear dimensional changes, distances between four reference points (A–B, A–C, A–D and B–C) were initially measured with a metal gauge accurate within 0.1 mm under a binocular stereo light microscope and data (mm) were recorded. Results: No significant difference of interfacial distance was found in sagittal and frontal sections measured 24 h after polymerization and after 30 days of water storage in any of experimental groups (P>.05). Significant difference of linear dimension were found in all experimental groups (P<.01) between measurements made 24 h after polymerization of specimens and 30 days after water storage. Conclusion: Palatal vault shape and fiber impregnation into the acrylic resin bases did not affect the magnitude of interfacial gaps between the bases and the stone cast surfaces. PMID:22229010

  8. Fabrication of detail parts for superconducting magnets by resin transfer molding

    SciTech Connect

    Behan, M.R.; Hartmann, J.G.

    1993-08-03

    A method is described of fabricating a detail part for a superconducting magnet and also of fabricating a coil winding assembly for a superconducting magnet, comprising the steps of: (a) utilizing engineering specifications for a detail part to produce a master mold part for the detail part, while taking into account a calculated resin shrinkage factor; (b) utilizing the master mold part to fabricate a resin transfer mold for the detail part; (c) placing a preform for the detail part into the resin transfer mold and closing the mold with the preform therein; (d) injecting a two-stage curing resin into the resin transfer mold; (e) heating the resin transfer mold to partially cure the molded detail part; (f) removing the partially cured detail part from the resin transfer mold; (g) fabricating a coil winding assembly, while precisely positioning the partially cured detail part relative to the coil windings to produce a coil winding assembly; (h) placing the coil winding assembly into a curing press, and pressing and heating the coil winding assembly in the curing press, during which the detail part conforms to the coil winding and cures completely to produce a final coil winding assembly for a superconducting magnet.

  9. Photocurable bioactive bone cement based on hydroxyethyl methacrylate-poly(acrylic/maleic) acid resin and mesoporous sol gel-derived bioactive glass.

    PubMed

    Hesaraki, S

    2016-06-01

    This paper reports on strong and bioactive bone cement based on ternary bioactive SiO2-CaO-P2O5 glass particles and a photocurable resin comprising hydroxyethyl methacrylate (HEMA) and poly(acrylic/maleic) acid. The as-cured composite represented a compressive strength of about 95 MPa but it weakened during soaking in simulated body fluid, SBF, qua its compressive strength reached to about 20 MPa after immersing for 30 days. Biodegradability of the composite was confirmed by reducing its initial weight (~32%) as well as decreasing the molecular weight of early cured resin during the soaking procedure. The composite exhibited in vitro calcium phosphate precipitation in the form of nanosized carbonated hydroxyapatite, which indicates its bone bonding ability. Proliferation of calvarium-derived newborn rat osteoblasts seeded on top of the composite was observed during incubation at 37 °C, meanwhile, an adequate cell supporting ability was found. Consequently, it seems that the produced composite is an appropriate alternative for bone defect injuries, because of its good cell responses, high compressive strength and ongoing biodegradability, though more in vivo experiments are essential to confirm this assumption. PMID:27040248

  10. In vitro analysis of different properties of acrylic resins for ocular prosthesis submitted to accelerated aging with or without photopolymerized glaze.

    PubMed

    Santos, Daniela Micheline Dos; Nagay, Bruna Egumi; da Silva, Emily Vivianne Freitas; Bonatto, Liliane da Rocha; Sonego, Mariana Vilela; Moreno, Amália; Rangel, Elidiane Cipriano; da Cruz, Nilson Cristino; Goiato, Marcelo Coelho

    2016-12-01

    The effect of a photopolymerized glaze on different properties of acrylic resin (AR) for ocular prostheses submitted to accelerated aging was investigated. Forty discs were divided into 4 groups: N1 AR without glaze (G1); colorless AR without glaze (G2); N1 AR with glaze (G3); and colorless AR with glaze (G4). All samples were polished with sandpaper (240, 600 and 800-grit). In G1 and G2, a 1200-grit sandpaper was also used. In G3 and G4, samples were coated with MegaSeal glaze. Property analysis of color stability, microhardness, roughness, and surface energy, and assays of atomic force microscopy, scanning electron microscopy, and energy-dispersive spectroscopy were performed before and after the accelerated aging (1008h). Data were submitted to the ANOVA and Tukey Test (p<0.05). Groups with glaze exhibited statistically higher color change and roughness after aging. The surface microhardness significantly decreased in groups with glaze and increased in groups without glaze. The surface energy increased after the aging, independent of the polishing procedure. All groups showed an increase of surface irregularities. Photopolymerized glaze is an inadequate surface treatment for AR for ocular prostheses and it affected the color stability, roughness, and microhardness. The accelerated aging interfered negatively with the properties of resins. PMID:27612795

  11. In vitro analysis of different properties of acrylic resins for ocular prosthesis submitted to accelerated aging with or without photopolymerized glaze.

    PubMed

    Santos, Daniela Micheline Dos; Nagay, Bruna Egumi; da Silva, Emily Vivianne Freitas; Bonatto, Liliane da Rocha; Sonego, Mariana Vilela; Moreno, Amália; Rangel, Elidiane Cipriano; da Cruz, Nilson Cristino; Goiato, Marcelo Coelho

    2016-12-01

    The effect of a photopolymerized glaze on different properties of acrylic resin (AR) for ocular prostheses submitted to accelerated aging was investigated. Forty discs were divided into 4 groups: N1 AR without glaze (G1); colorless AR without glaze (G2); N1 AR with glaze (G3); and colorless AR with glaze (G4). All samples were polished with sandpaper (240, 600 and 800-grit). In G1 and G2, a 1200-grit sandpaper was also used. In G3 and G4, samples were coated with MegaSeal glaze. Property analysis of color stability, microhardness, roughness, and surface energy, and assays of atomic force microscopy, scanning electron microscopy, and energy-dispersive spectroscopy were performed before and after the accelerated aging (1008h). Data were submitted to the ANOVA and Tukey Test (p<0.05). Groups with glaze exhibited statistically higher color change and roughness after aging. The surface microhardness significantly decreased in groups with glaze and increased in groups without glaze. The surface energy increased after the aging, independent of the polishing procedure. All groups showed an increase of surface irregularities. Photopolymerized glaze is an inadequate surface treatment for AR for ocular prostheses and it affected the color stability, roughness, and microhardness. The accelerated aging interfered negatively with the properties of resins.

  12. Evaluation of adhesion of reline resins to the thermoplastic denture base resin for non-metal clasp denture.

    PubMed

    Kim, Ji Hye; Choe, Han Cheol; Son, Mee Kyoung

    2014-01-01

    This study aimed to evaluate the tensile and transverse bond strength of chairside reline resins (Tokuyama Rebase II, Mild Rebaron LC) to a thermoplastic acrylic resin (Acrytone) used for non metal clasp denture. The results were compared with those of a conventional heat polymerized acrylic resin (Paladent 20) and a thermoplastic polyamide resin (Biotone). The failure sites were examined by scanning electron microscopy to evaluate the mode of failure. As results, the bond strength of reline resins to a thermoplastic acrylic resin was similar to the value of a conventional heat polymerized acrylic resin. However, thermoplastic polyamide resin showed the lowest value. The results of this study indicated that a thermoplastic acrylic resin for non metal clasps denture allows chairside reline and repair. It was also found that the light-polymerized reline resin had better bond strength than the autopolymerizing reline resin in relining for a conventional heat polymerized acrylic resin and a thermoplastic acrylic resin.

  13. Epoxy-resin patterns speed shell-molding of aluminum parts

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Half patterns cast from commercial epoxy resin containing aluminum powder are used for shell-molding of aluminum parts. The half patterns are cast in plastic molds of the original wooden pattern. Ten serviceable sand resin molds are made from each epoxy pattern.

  14. The effect of surface treatment of denture acrylic resin on the residual monomer content and its release into water.

    PubMed

    Vallittu, P K

    1996-06-01

    The test specimens were processed by autopolymerizing poly(methylmethacrylate) (PMMA), and their surfaces were untreated, polished in a conventional manner with a rag wheel, or coated with a light-curing resin. The residual methylmethacrylate (MMA) content and its release into water from the specimens were measured with high-performance liquid chromatography. The light-curing resin coating reduced most effectively the release of residual MMA into water during a 2-day storage, but conventional polishing of the PMMA surface had a similar effect when the mean values of groups were tested by means of one-way ANOVA (p < 0.001). The residual MMA content was lowest in the test specimens coated with a light-curing resin, whereas only a slight difference was seen when the untreated and polished test specimens were compared. This study suggests that not only light-curing resin coating but also the conventional polishing of the denture PMMA reduces residual MMA release into water in vitro.

  15. Acrylic resins: methacrylate polymers. 1964-April, 1981 (citations from the NTIS data base). Report for 1964-April 1981

    SciTech Connect

    Not Available

    1981-05-01

    Polymethyl methacrylate, polymethacrylic acid, and other methacrylate and methacrylic polymers, copolymers, and resins are covered in this bibliography. The citations include references concerning physical and chemical properties, synthesis, polymerization, and processing. (This updated bibliography contains 278 citations, 40 of which are new entries to the previous edition.)

  16. In vitro color change of three dental veneering resins in tea, coffee and tamarind extracts

    PubMed Central

    Subramanya, J.K.; Muttagi, S.

    2011-01-01

    Objective To study the in vitro color changes of three dental resin veneering materials when immersed in tea, coffee and tamarind extracts. Materials and Methods The color changes of heat polymerized tooth colored acrylic resin (Stellondetrey, B, F14, DPI Dental products of India Ltd, Mumbai), auto polymerized tooth colored acrylic resin (DPI, B, QV5, DPI Dental products of India Ltd, Mumbai) and light polymerized resin composite (Herculite XRV, Enamel A2, part no. 22860, lot no. 910437, Kerr Corporation, West Collins Avenue, Orange, CA, USA) when immersed in water extracts of tea (Tata Tea Ltd. Bangalore, India), coffee (Tata Coffee Ltd. Coorg, India) and tamarind were evaluated using computer vision systems. The color images were recorded in R (red), G (green) and B (blue) form and converted into H (hue), S (saturation) and V (value). Results Significant color change occurred for auto polymerized tooth colored acrylic resin in tamarind extract, for heat polymerized tooth colored acrylic resin in tea extract and for light polymerized resin composite in coffee extract. Auto polymerized tooth colored acrylic resin samples showed an overall higher color change. However, for all the material samples coffee extract produced more color change. Conclusion These results suggest that the color stability of the resins is influenced by the presence of secondary metabolites such as tartaric acid, tannins, caffeine, saponins and phenols in tamarind, tea and coffee extracts. PMID:22457841

  17. DGEBF epoxy blends for use in the resin impregnation of extremely large composite parts

    DOE PAGES

    Madhukar, M. S.; Martovetsky, N. N.

    2015-01-16

    Large superconducting electromagnets used in fusion reactors utilize a large amount of glass/epoxy composite for electrical insulation and mechanical and thermal strengths. Moreover, the manufacture of these magnets involves wrapping each superconducting cable bundle with dry glass cloth followed by the vacuum-assisted resin transfer molding of the entire magnet. Due to their enormous size (more than 100 tons), it requires more than 40 h for resin impregnation and the subsequent pressure cycles to ensure complete impregnation and removal of any trapped air pockets. Diglycidyl ether of bisphenol F epoxy resin cross-linked with methyltetrahydrophthalic anhydride with an accelerator has been shownmore » to be a good candidate for use in composite parts requiring long impregnation cycles. Viscosity, gel time, and glass transition temperature of four resin-blends of diglycidyl ether of bisphenol F resin system were monitored as a function of time and temperature with an objective to find the blend that provides a working window longer than 40h at low viscosity without lowering its glass transition temperature. A resin-blend in the weight ratios of resin:hardener:accelerator=100:82:0.125 is shown to provide more than 60h at low resin viscosity while maintaining the same glass transition temperature as obtained with previously used resin-blends, based on the results.« less

  18. DGEBF epoxy blends for use in the resin impregnation of extremely large composite parts

    SciTech Connect

    Madhukar, M. S.; Martovetsky, N. N.

    2015-01-16

    Large superconducting electromagnets used in fusion reactors utilize a large amount of glass/epoxy composite for electrical insulation and mechanical and thermal strengths. Moreover, the manufacture of these magnets involves wrapping each superconducting cable bundle with dry glass cloth followed by the vacuum-assisted resin transfer molding of the entire magnet. Due to their enormous size (more than 100 tons), it requires more than 40 h for resin impregnation and the subsequent pressure cycles to ensure complete impregnation and removal of any trapped air pockets. Diglycidyl ether of bisphenol F epoxy resin cross-linked with methyltetrahydrophthalic anhydride with an accelerator has been shown to be a good candidate for use in composite parts requiring long impregnation cycles. Viscosity, gel time, and glass transition temperature of four resin-blends of diglycidyl ether of bisphenol F resin system were monitored as a function of time and temperature with an objective to find the blend that provides a working window longer than 40h at low viscosity without lowering its glass transition temperature. A resin-blend in the weight ratios of resin:hardener:accelerator=100:82:0.125 is shown to provide more than 60h at low resin viscosity while maintaining the same glass transition temperature as obtained with previously used resin-blends, based on the results.

  19. Study of the elution of fluconazole from a self-polymerizing acrylic resin and its activity against resistant Candida albicans.

    PubMed

    Darwish, Rula M; Amin, Wala M; Al-Ali, Muna H; Salem, Nesreen A

    2011-08-01

    The study aimed, firstly, to monitor the release of an antifungal drug, fluconazole, from a self-polymerizing poly(methyl methacrylate) (PMMA) denture base resin in artificial saliva and comparing it with the release in water; and secondly, to investigate the effect of the released drug on the growth of resistant and standard strains of Candida albicans. A high-performance liquid chromatography-ultra-violet (HPLC-UV) method was used in the analysis of the released eluates into distilled water from self-polymerized PMMA discs doped with the 10% fluconazole antifungal drug. The efficacy of the released drug against resistant and standard strains of C. albicans was monitored, using agar diffusion method. The results showed that fluconazole, can be successfully incorporated with the self-polymerized PMMA. The findings suggest that the drug leaches steadily out of the PMMA resin into artificial saliva and distilled water at mouth temperature and that sustained drug release continued throughout the 28 days test period. It was shown that the released drug demonstrated antifungal activity against both standard and resistant C. albicans. The findings of this investigation have a clinical value in terms of their significant contribution to the treatment of fungal infections of the oral cavity. The sustained release of antifungal drug from the PMMA resin clearly constitutes a new dosage form of the drug via the poly(methyl methacrylate) delivery system.

  20. Spectroscopic study performed on films of (3-trimethoxysilylpropyl) ethylenediamine and a dental material (acrylic resin) doped with the luminescent complexes Eu(fod) 3·2H 2O and Eu(fod) 3·terpy

    NASA Astrophysics Data System (ADS)

    de Farias, Robson F.; Alves, Severino; Belian, Mônica F.; Vieira, Magda R. S.; de Souza, Jucimar M.; Pedrosa, Gilmara G.; de Sá, Gilberto F.

    2002-10-01

    By using (3-trimethoxysilylpropyl) ethylenediamine (TSPED) and a dental material (acrylic resin) as precursors, self-standing films doped with the luminescent complexes Eu(fod) 3·2H 2O and Eu(fod) 3·terpy were prepared. The doped films were so studied from a spectroscopic point of view. Is verified that the film composition exerts remarkable effects on both, the intensity and lifetime of the emission process. Acrylic resin films reduces the intensity of the emission process, but increases the lifetime of a such process, in comparison with TSPED films, for which an opposite behavior is observed. The measured lifetimes for the emission process for the compounds Eu(fod) 3·2H 2O in TSPED and acrylic resin films are 306 and 369 μs, respectively. For the same film matrices, the measured lifetimes for the complex Eu(fod) 3·terpy gave the values 347 and 880 μs, respectively.

  1. Chemoviscosity modeling for thermosetting resin systems, part 3

    NASA Technical Reports Server (NTRS)

    Hou, T. H.; Bai, J. M.

    1988-01-01

    A new analytical model for simulating chemoviscosity resin has been formulated. The model is developed by modifying the well established Williams-Landel-Ferry (WLF) theory in polymer rheology for thermoplastic materials. By introducing a relationship between the glass transition temperature (T sub g (t)) and the degree of cure alpha(t) of the resin system under cure, the WLF theory can be modified to account for the factor of reaction time. Temperature-dependent functions of the modified WLF theory parameters C sub 1 (T) and C sub 2 (T) were determined from the isothermal cure data. Theoretical predictions of the model for the resin under dynamic heating cure cycles were shown to compare favorably with the experimental data. This work represents a progress toward establishing a chemoviscosity model which is capable of not only describing viscosity profiles accurately under various cure cycles, but also correlating viscosity data to the changes of physical properties associated with the structural transformations of the thermosetting resin systems during cure.

  2. Characterization of fiberglass-filled diallyl phthalate plastic molding resins and molded parts

    SciTech Connect

    Whitaker, R.B.; Glaub, J.E.; Bonekowski, N.R.; Gillham, P.D.

    1980-12-01

    Characterization of diallyl phthalate (DAP) molding resins was undertaken by differential scanning calorimetry (DSC) and by combined size exclusion chromatography (SEC)/low angle laser light scattering (LALLS) in order to better predict moldability and storage life limits. Completeness of cure of molded parts, before and after any post-curing, was also determined by thermal analysis. Molecular weights and molecular weight distributions of the DAP molding resins by SEC/LALLS indicated that the better molding resins have lower M/sub w//M/sub n/ ratios. Association effects were observed, which could not be overcome by solvent modification alone. Determination of DAP molding resin heats of reaction by DSC indicated a linear relation between ..delta..H/sub R/ and weight percent filler for the good molding resins. DSC analyses of molded DAP parts showed that 95% cure was achieved in some as-molded parts, with a post-cure temperature of 165/sup 0/C being required to complete the cure to 100%. Thickness of the parts was a factor, with the thicker parts being 100% cured as molded. The glass transition temperature (T/sub g/) of the molded parts increased as cure was completed, to approx. 160 to 165/sup 0/C maximum. These results are consistent with a model of thermoset resin curing behavior which states that 100% cure can be achieved only if a post-curing operation is conducted above the T/sub g infinity/ (T/sub g/ at complete cure) of the polymer.

  3. Prosthetic rehabilitation with collapsible hybrid acrylic resin and permanent silicone soft liner complete denture of a patient with scleroderma-induced microstomia.

    PubMed

    Singh, Kunwarjeet; Gupta, Nidhi; Gupta, Ridhimaa; Abrahm, Dex

    2014-07-01

    Scleroderma is an autoimmune multisystem rheumatic condition characterized by fibrosis of connective tissues of the body, resulting in hardening and impairment of the function of different organs. Deposition of collagen fibers in peri-oral tissues causes loss of elasticity and increased tissue stiffness, resulting in restricted mouth opening. A maximal oral opening smaller than the size of a complete denture can make prosthetic treatment challenging. Patients with microstomia who must wear removable dental prostheses (RDPs) often face the difficulty of being unable to insert or remove a conventional RDP. A sectional-collapsible denture is indicated for the prosthetic management of these patients, but reduced manual dexterity often makes intraoral manipulation of the prosthesis difficult. A single collapsible complete denture is a better choice for functional rehabilitation of these patients. This clinical report describes in detail the prosthodontic management of a maxillary edentulous patient with restricted mouth opening induced by scleroderma with a single collapsible removable complete denture fabricated with heat-polymerized silicone soft liner and heat-cured acrylic resin. The preliminary and secondary impressions were made with moldable aluminum trays by using putty and light-body poly(vinyl siloxane) elastomeric impression material. The collapsed denture can be easily inserted and removed by the patient and also provides adequate function in the mouth.

  4. Color stability of the artificial iris button in an ocular prosthesis before and after acrylic resin polymerization.

    PubMed

    Moreno, Amália; Goiato, Marcelo Coelho; Oliveira, Kamila Freitas; Iyda, Mariana Garib; Haddad, Marcela Filié; de Carvalho Dekon, Stefan Fiuza; dos Santos, Daniela Micheline

    2015-12-01

    This study investigated the effects of the ocular prosthesis fabrication technique and the paint on the color stability of the artificial iris button before and after polymerization of the colorless resin. Sixty samples simulating artificial eyes were made, including 30 samples with blue- and 30 samples with sepia-colored artificial irises. Ten samples were made by each of three techniques (i.e., conventional, prefabricated cap, and inverted painting) for each color. The color of the artificial iris button was measured through reflection spectrophotometry by the CIE L*a* b* system before and after polymerization of the prosthesis (colorless resin). Data were evaluated by analysis of variance (ANOVA) and the Tukey honestly significant different (HSD) tests (α=0.05). All of the samples exhibited color changes. Samples made by the prefabricated cap technique exhibited the highest color change values for both colors (P<.05). The inverted painting technique exhibited the lowest color change values for the sepia-colored artificial irises (P<.05). Sepia-colored artificial irises exhibited lower color change values than blue-colored artificial irises for both techniques (P<.05). In conclusion, the technique used to obtain the ocular prosthesis significantly affected the stability of the artificial iris color for each color tone and the conventional technique and the painting technique inverted were considered clinically acceptable for sepia color.

  5. Synthesis of glycerol-derived diallyl spiroorthocarbonates and the study of their antishrinking properties in acrylic dental resins.

    PubMed

    Acosta Ortiz, Ricardo; Reyna Medina, Luis Alberto; Berlanga Duarte, María Lydia; Ibarra Samaniego, Lucía; Garcia Valdez, Aida Esmeralda; García Mendez, Zaida Lucía; Mendez Gonzalez, Luis

    2013-08-01

    In this work was evaluated the efficiency of an antishrinkage additive in a dental resin. This additive was a mixture 1:1 of five and six-membered ring spiroorthocarbonates functionalized with allylic groups (SOC DA). The aim of this study was to reduce the shrinkage of a typical dental resin composed of a blend of the dimethacrylates, Glycerolate bisphenol A dimethacrylate (Bis-GMA)/2-[(3,5,5-trimethyl-6-[2-(2-methyl prop-2-enoyloxy) ethoxycarbonylamino] hexyl) carbamoyloxy] ethyl, 2-methyl prop-2-enoate, (UDMA)/triethyleneglycol dimethacrylate (TEGDMA) in a 50:30.20 molar ratio, and silicon dioxide as filler. SOC DA was added at 5, 10 and 20 mol% to the already mentioned formulation. It was found that the addition of 20 mol% of SOC DA decreased 53 % the shrinkage of the cured composite material, in comparison with a formulation where it was not added the antishrinkage additive. Besides, the kinetics of photopolymerization determined by Real-Time infrared spectroscopy, demonstrated that the addition of increasing concentration of SOC DA improved the conversion of double bonds of dimethacrylates. Additionally, the presence of SOC DA at 10 % mol, helped to increase the flexural strength and the compressive strength of the composite, as a consequence of the augment of the crosslink density, induced by the ring opening polymerization of SOC DA.

  6. Safeguards Analytical Laboratory evaluation program. Part 1. Resin bead mass spectrometry. Part 2. Results of a resin bead field experiment-Tastex-J

    SciTech Connect

    Walker, R.L.; Smith, D.H.; Carter, J.A.; Musick, W.R.; Donohue, D.L.; Deron, S.; Asakura, Y.; Kagami, K.; Irinouchi, S.; Masui, J.

    1981-01-01

    The first part of this report covers background of resin bead spectrometry and the new batch resin bead method. In the original technique, about ten anion resin beads in the nitrate form were exposed to the diluted sample solution. The solution was adjusted to be a 8 M HNO/sub 3/ and to have about 1 ..mu..g U per bead. Up to 48 hours of static contact between beads and solution was required for adsorption of 1 to 3 ng Pu and U per bead to be achieved. Under these conditions, contamination was a problem at reprocessing facilities. The new batch techniques reduces the risk of contamination by handling one hundred times more U in the final diluted sample which is exposed to a proportionately larger number of beads. Moreover, it only requires ten minutes adsorption time to provide about 1000 purified samples for mass spectrometry. The amounts of Pu and U adsorbed versus time were determined and results are tabulated. The second part of this report briefly summarizes results of resin bead field tests completed at the Power Reactor and Nuclear Fuel Development Corporation (PNC) reprocessing plant in Tokai-mura, Japan. Both methods, the original small-sample resin bead and the batch technique, were investigated on spent fuel solutions. Beads were prepared at PNC and distributed to IAEA and ORNL along with dried residues for conventional mass spectrometric analysis at IAEA. Parallel measurements were made at PNC using their normal measuring routines. The U and Pu measurements of all resin and those of PNC are in excellent agreement for the batch method. Discrepancies were noted in the U measurements by the original method.

  7. Peel bond strength of resilient liner modified by the addition of antimicrobial agents to denture base acrylic resin

    PubMed Central

    ALCÂNTARA, Cristiane S.; de MACÊDO, Allana F.C.; GURGEL, Bruno C.V.; JORGE, Janaina H.; NEPPELENBROEK, Karin H.; URBAN, Vanessa M.

    2012-01-01

    In order to prolong the clinical longevity of resilient denture relining materials and reduce plaque accumulation, incorporation of antimicrobial agents into these materials has been proposed. However, this addition may affect their properties. Objective This study evaluated the effect of the addition of antimicrobial agents into one soft liner (Soft Confort, Dencril) on its peel bond strength to one denture base (QC 20, Dentsply). Material and Methods Acrylic specimens (n=9) were made (75x10x3 mm) and stored in distilled water at 37ºC for 48 h. The drug powder concentrations (nystatin 500,000U - G2; nystatin 1,000,000U - G3; miconazole 125 mg - G4; miconazole 250 mg - G5; ketoconazole 100 mg - G6; ketoconazole 200 mg - G7; chlorhexidine diacetate 5% - G8; and 10% chlorhexidine diacetate - G9) were blended with the soft liner powder before the addition of the soft liner liquid. A group (G1) without any drug incorporation was used as control. Specimens (n=9) (75x10x6 mm) were plasticized according to the manufacturers' instructions and stored in distilled water at 37ºC for 24 h. Relined specimens were then submitted to a 180-degree peel test at a crosshead speed of 10 mm/min. Data (MPa) were analyzed by analysis of variance (α=0.05) and the failure modes were visually classified. Results No significant difference was found among experimental groups (p=0.148). Cohesive failure located within the resilient material was predominantly observed in all tested groups. Conclusions Peel bond strength between the denture base and the modified soft liner was not affected by the addition of antimicrobial agents. PMID:23329241

  8. Toughening mechanism in elastometer-modified epoxy resins: Part 1

    NASA Technical Reports Server (NTRS)

    Yee, A. F.; Pearson, R. A.

    1983-01-01

    Several plaques of Epon 828, cured with piperidine, modified with hycar(r) CTBN 1300X8, Hycar(R) CTBN 1300X13, and Hycar(R) CTBN 1300x15, and in some cases modified with biphenol A (BPA), yielded properly toughened epoxies with rubber particle diameters ranging from 0.1 to 10 microns. Fracture toughness experiments indicate that toughness was more a function of rubber content than the rubber particle size. Tensile volumetric behavior of the near resin exhibits two regions: an initial region where the increase in volume strain was due to the Poisson's effect, and a second region where a slower rate of increase in volume strain was due to shear deformation. Tensile volumetric deformation of an elastomer-modified epoxy exhibits the same type of behavior to that of the neat resin at low rates ( 3.2x0.01 sec(-1)). But at very high strain rates, which correspond more closely to the strain rates at the crack tip, there exists an increase in volume strain beyond the Poisson's effect. TEM, SEM and OM studies indicate that the rubber particles had voided. When a thin section from the deformed region is viewed under crossed-polarized light, shear bands are seen connecting voided rubber particles. From this information cavitation and enhanced shear band formation is proposed as the toughening mechanism.

  9. Effect of Food Simulating Agents on the Hardness and Bond Strength of a Silicone Soft Liner to a Denture Base Acrylic Resin

    PubMed Central

    Khaledi, A.A.R.; Bahrani, M.; Shirzadi, S.

    2015-01-01

    Statement of the Problem: Bonding failure between acrylic resin and soft liner material and also gradual loss of soft liner resiliency over time are two impending challenges frequently recognized with a denture base embraced with a resilient liner. Since patients drink various beverages, it is crucial to assess the influences of these beverages on physical characteristics of soft liners. Purpose: This in vitro study envisioned to assess the influence of food simulating agents (FSA) on the hardness of a silicone soft liner by employing a Shore A durometer test and also evaluate its bond strength to a denture base resin by using tensile bond strength test. Materials and Methods: To test the hardness of samples, 50 rectangular samples (40 mm × 10 mm × 3 mm) were prepared from a heat-polymerized polymethyl methacrylate (Meliodent). Mollosil, a commercially available silicone resilient liner, was provided and applied on the specimens following the manufacturer’s directions. In order to test tensile bond strength, 100 cylindrical specimens (30 mm × 10 mm) were fabricated. The liners were added between specimens with the thicknesses of 3 mm. The specimens were divided into 5 groups (n=10) and immersed in distilled water, heptane, citric acid, and 50% ethanol. For each test, we used 10 specimens as a baseline measurement; control group. All specimens were kept in dispersed containers at 37ºC for 12 days and all solutions were changed every day. The hardness was verified using a Shore A durometer and the tensile bond strength was examined by an Instron testing machine at a cross-head speed of 5 mm/min. The records were analyzed employing one-way ANOVA, Tukey’s HSD, and LSD tests. Results: The mean tensile bond strength ± standard deviation (SD) for Mollosil was as follows for each group: 3.1 ± 0.4 (water), 1.8 ± 0.4 (citric acid), 3.0 ± 0.4 (heptane), 1.2 ± 0.3 (50% ethanol), and 3.8 ± 0.4 (control). The hardness values for each group were: 28.7 ± 2.11 (water

  10. [Comparative evaluation of physical-mechanical properties and surface morphology of the samples of base self cured acrylic resin "Redont-kolir" polymerized in the silicone and alginate matrixes].

    PubMed

    2014-01-01

    Determination of advantages of using silicone or alginate impression material as a matrix is decisive for quality of immediate and transitional dentures manufactured by the direct method using self-cured acrylic resins. The aim of this study was a comparative evaluation of physical-mechanical properties and surface morphology of the samples of base self-cured acrylic resin "Redont-kolir" polymerized in the silicone and alginate matrix. The samples were polymerized in the C-silicone - "Zeta plus-putty" ("Zhermack", Italy) and alginate -"Ypeen" ("Spofa Dental", Czech Republic) matrixes under different regimes: 1) in the pneumopolymerizer "Averon" at an air pressure of 3 atm., a temperature of 450C for 15 minutes, and 2) polymerization in water at 450C for 15 minutes. We determined the following physical and mechanical properties: bending load, toughness, bending stress at break, hardness by Heppler, conical point of fluidity and water absorption. Electron microscopy studies of the samples have been conducted on electronic raster microscope JSM-840 ("Jeol", Japan). As a result of studies, it was found that the optimum regime of polymerization for acrylate "Redont-kolir" is in the pneumopolymerizer "Averon" at an air pressure of 3 atm., a temperature of 450 C for 15 minutes. By the results of studying the surface morphology of the samples we can draw a conclusion that the use of an alginate impression material as matrix allows to obtain a qualitatively better surface of denture. But taking into account the technological properties of the alginate impression materials, namely an expressed shrinkage, their use for this purpose must be limited by the time during which the impression matrix remain stable in size, which is specified by manufacturer's recommendations.

  11. Poly(amide-graft-acrylate) interfacial compounds

    NASA Astrophysics Data System (ADS)

    Zamora, Michael Perez

    Graft copolymers with segments of dissimilar chemistries have been shown to be useful in a variety of applications as surfactants, compatibilizers, impact modifiers, and surface modifiers. The most common route to well defined graft copolymers is through the use of macromonomers, polymers containing a reactive functionality and thus capable of further polymerization. However, the majority of the studies thus far have focused on the synthesis of macromonomers capable of reacting with vinyl monomers to form graft copolymers. This study focused on the synthesis of macromonomers capable of participating in condensation polymerizations. A chain transfer functionalization method was utilized. Cysteine was evaluated as a chain transfer agent for the synthesis of amino acid functionalized poly(acrylate) and poly(methacrylate) macromonomers. Low molar mass, functionalized macromonomers were produced. These macromonomers were proven to be capable of reacting with amide precursors to form poly(amide-g-acrylate) graft copolymers. Macromonomers and graft copolymers were characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) spectroscopy, elemental analysis (EA), inductively coupled plasma (ICP), and differential scanning calorimetry (DSC). The second part of this research involved poly(dimethacrylate) dental restorative materials. Volumetric shrinkage during the cure of these resins results in a poor interface between the resin and the remaining tooth structure, limiting the lifetime of these materials. Cyclic anhydrides were incorporated into common monomer compositions used in dental applications. Volume expansion from the ring opening hydrolysis of these anhydrides was shown to be feasible. The modified dental resins were characterized by swelling, extraction and ultraviolet spectroscopy (UV), and density measurements. Linear poLymers designed to model the crosslinked dental resins were

  12. Simple guidelines for aesthetic success with composite resin--Part I: anterior restorations.

    PubMed

    Boer, Wolfgang M

    2007-04-01

    Composite restorations have the advantage of being created in the dental office, which can lead to beautiful, natural aesthetics. Laboratory technicians tend to spend minimal time with the patient and reconstruct the restoration based on information provided by the clinician. Dentists, however, are at a great advantage, as they can refer to the surrounding tooth structure when building the restoration. Part I of this article will discuss various guidelines for treating anterior teeth using direct resin restorations, while Part II will address posterior restorations.

  13. Comparative evaluation of effect of metal primer and sandblasting on the shear bond strength between heat cured acrylic denture base resin and cobalt-chromium alloy: An in vitro study

    PubMed Central

    Kalra, Sandeep; Kharsan, Vishwas; Kalra, Nidhi Mangtani

    2015-01-01

    Aims: The aim of this study was to evaluate the effect of metal primers and sandblasting on the shear bond strength (SBS) of heat cured acrylic denture base resin to cobalt-chromium (Co-Cr) alloy. Materials and Methods: A total number of 40 disk shaped wax patterns (10 mm in diameter and 2 mm in thickness) were cast in Co-Cr alloy. Samples were divided into 4 groups depending on the surface treatment received. Group 1: No surface treatment was done and acts as control group. Group 2: Only sandblasting was done. Group 3: Only metal primer was applied. Group 4: Both metal primer and sandblasting were done. After surface treatment samples had been tested in Universal Testing Machine at crosshead speed of 0.5 mm/min in shear mode and scanning, electron microscope evaluation was done to observe the mode of failure. Statistical Analysis: All the observations obtained were analyzed statistically using software SPSS version 17; one-way analysis of variance (ANOVA) and post-hoc Tukey test were applied. Results: The one-way ANOVA indicated that SBS values varied according to type of surface treatment done. The SBS was highest (18.70 ± 1.2 MPa) when both sandblasting and metal primer was done when compared with no surface treatment (2.59 ± 0.32 MPa). Conclusions: It could be concluded that the use of metal primers along with sandblasting significantly improves the bonding of heat cured acrylic denture base resin with the Co-Cr alloy. PMID:26321840

  14. Light-curing considerations for resin-based composite materials: a review. Part I.

    PubMed

    Malhotra, Neeraj; Mala, Kundabala

    2010-09-01

    There has been a continual advent of improved technologies in dentistry. Among these are the material sciences of resin-based composites (RBCs). Since the introduction of light-cured RBCs, the problem of polymerization shrinkage and the methods used to overcome this have concerned clinicians and researchers. Types of curing light and modes of curing have been shown to affect the degree of polymerization and related shrinkage of RBCs. This review, which is divided into two parts, discusses the contemporary light-curing units. Part I explores the evolution in light-curing units and different curing modes. Part II highlights the clinical considerations regarding light curing of RBCs that are important for achieving optimal curing and maximum polymerization of RBCs in a clinical setting. PMID:20879203

  15. Light-curing considerations for resin-based composite materials: a review. Part II.

    PubMed

    Malhotra, Neeraj; Mala, Kundabala

    2010-10-01

    As discussed in Part I, the type of curing light and curing mode impact the polymerization kinetics of resin-based composite (RBC) materials. Major changes in light-curing units and curing modes have occurred. The type of curing light and mode employed affects the polymerization shrinkage and associated stresses, microhardness, depth of cure, degree of conversion, and color change of RBCs. These factors also may influence the microleakage in an RBC restoration. Apart from the type of unit and mode used, the polymerization of RBCs is also affected by how a light-curing unit is used and handled, as well as the aspects associated with RBCs and the environment. Part II discusses the various clinical issues that should be considered while curing RBC restorations in order to achieve the best possible outcome. PMID:20960988

  16. Acrylic acid

    Integrated Risk Information System (IRIS)

    Acrylic acid ( CASRN 79 - 10 - 7 ) Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  17. Methyl acrylate

    Integrated Risk Information System (IRIS)

    Methyl acrylate ; CASRN 96 - 33 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  18. Rehabilitation of Oncology Patients with Hard Palate Defects Part 3: Construction of an Acrylic Hollow Box Obturator.

    PubMed

    Ali, Rahat; Altaie, Asmaa; Nattress, Brian

    2015-09-01

    This article will discuss the clinical stages in the fabrication of a definitive acrylic hollow box obturator to restore a hard palate defect. The first two papers described the restorative/surgical planning phase and the principles of obturator design. CPD/CLINICAL RELEVANCE: Each of the clinical stages required to make a hollow box obturator must be performed to the highest possible standard to ensure than an optimal prosthesis.is fabricated.

  19. The Effect of Artificial Aging on The Bond Strength of Heat-activated Acrylic Resin to Surface-treated Nickel-chromium-beryllium Alloy

    PubMed Central

    Al Jabbari, Youssef S.; Zinelis, Spiros; Al Taweel, Sara M.; Nagy, William W.

    2016-01-01

    Purpose The debonding load of heat-activated polymethylmethacrylate (PMMA) denture base resin material to a nickel-chromium-beryllium (Ni-Cr-Be) alloy conditioned by three different surface treatments and utilizing two different commercial bonding systems was investigated. Materials and Methods Denture resin (Lucitone-199) was bonded to Ni-Cr-Be alloy specimens treated with Metal Primer II, the Rocatec system with opaquer and the Rocatec system without opaquer. Denture base resin specimens bonded to non-treated sandblasted Ni-Cr-Be alloy were used as controls. Twenty samples for each treatment condition (80 specimens) were tested. The 80 specimens were divided into two categories, thermocycled and non-thermocycled, containing four groups of ten specimens each. The non-thermocycled specimens were tested after 48 hours’ storage in room temperature water. The thermocycled specimens were tested after 2,000 cycles in 4°C and 55°C water baths. The debonding load was calculated in Newtons (N), and collected data were subjected by non parametric test Kruskal-Wallis One Way Analysis of Variance on Ranks and Dunn’s post hoc test at the α = 0.05. Results The Metal Primer II and Rocatec system without opaquer groups produced significantly higher bond strengths (119.9 and 67.6 N), respectively, than did the sandblasted and Rocatec system with opaquer groups, where the bond strengths were 2.6 N and 0 N, respectively. The Metal Primer II was significantly different from all other groups (P<0.05). The bond strengths of all groups were significantly decreased (P<0.05) after thermocycling. Conclusions Although thermocycling had a detrimental effect on the debonding load of all surface treatments tested, the Metal Primer II system provided higher values among all bonding systems tested, before and after thermocycling. PMID:27335613

  20. An in vitro study into the effect of a limited range of denture cleaners on surface roughness and removal of Candida albicans from conventional heat-cured acrylic resin denture base material.

    PubMed

    Harrison, Z; Johnson, A; Douglas, C W I

    2004-05-01

    This study evaluated the abrasiveness of four denture cleaners on the surface of denture base material and assessed their ability to remove Candida albicans. Acrylic resin discs 20 mm diameter and 2 mm thick were identically produced and polished. Four cleaners were evaluated: conventional toothpaste; toothpaste with stain remover; denture cleaning paste and an immersion type cleaner, and water were used as control. These were used at dilutions of 1:1, 1:2 and 1:3 with water. An electric toothbrush was used, and the discs cleaned to simulate 1 years' cleaning. The surface roughness of the discs were then measured, before and after cleaning, using a stylus profilometer, then inoculated with 1.2 x 10(6)C. albicans cells. The effectiveness of the denture cleaners to remove C. albicans cells was assessed following a single cleaning event. The immersion cleaner was significantly less abrasive than paste cleaners (P < 0.05). There were no significant differences between any dilutions for any cleaner used (P > 0.05). Immersion and paste cleaners removed almost all recoverable C. albicans from the discs, as cleaning with water alone was less effective (P < 0.05). An immersion type cleaner was found to be the most suitable cleaner because of its low abrasivity and effective removal of organic debris. PMID:15140172

  1. Optimization of Resin Infusion Processing for Composite Pipe Key-Part and K/T Type Joints Using Vacuum-Assisted Resin Transfer Molding

    NASA Astrophysics Data System (ADS)

    Wang, Changchun; Bai, Guanghui; Yue, Guangquan; Wang, Zhuxi; Li, Jin; Zhang, Boming

    2016-10-01

    In present study, the optimization injection processes for manufacturing the composite pipe key-part and K/T type joints in vacuum-assisted resin transfer molding (VARTM) were determined by estimating the filling time and flow front shape of four kinds of injection methods. Validity of the determined process was proved with the results of a scaling-down composite pipe key-part containing of the carbon fiber four axial fabrics and a steel core with a complex surface. In addition, an expanded-size composite pipe part was also produced to further estimate the effective of the determined injection process. Moreover, the resin injection method for producing the K/T type joints via VARTM was also optimized with the simulation method, and then manufactured on a special integrated mould by the determined injection process. The flow front pattern and filling time of the experiments show good agreement with that from simulation. Cross-section images of the cured composite pipe and K/T type joints parts prove the validity of the optimized injection process, which verify the efficiency of simulation method in obtaining a suitable injection process of VARTM.

  2. Optimization of Resin Infusion Processing for Composite Pipe Key-Part and K/T Type Joints Using Vacuum-Assisted Resin Transfer Molding

    NASA Astrophysics Data System (ADS)

    Wang, Changchun; Bai, Guanghui; Yue, Guangquan; Wang, Zhuxi; Li, Jin; Zhang, Boming

    2016-05-01

    In present study, the optimization injection processes for manufacturing the composite pipe key-part and K/T type joints in vacuum-assisted resin transfer molding (VARTM) were determined by estimating the filling time and flow front shape of four kinds of injection methods. Validity of the determined process was proved with the results of a scaling-down composite pipe key-part containing of the carbon fiber four axial fabrics and a steel core with a complex surface. In addition, an expanded-size composite pipe part was also produced to further estimate the effective of the determined injection process. Moreover, the resin injection method for producing the K/T type joints via VARTM was also optimized with the simulation method, and then manufactured on a special integrated mould by the determined injection process. The flow front pattern and filling time of the experiments show good agreement with that from simulation. Cross-section images of the cured composite pipe and K/T type joints parts prove the validity of the optimized injection process, which verify the efficiency of simulation method in obtaining a suitable injection process of VARTM.

  3. Acrylic coatings compositions containing polymer-bound hindered amine light stabilizers

    SciTech Connect

    Callais, P.A.

    1993-12-31

    Unique acrylic coatings resins with attached hindered amine light stabilizer (HALS) groups have been developed. They are readily prepared by reacting a hydrazide functionalized HALS with an acrylic polyol resin containing anhydride and/or epoxy groups or with a peroxide functionalized HALS as the polymerization initiator. As a result, the HALS moiety is rendered nonvolatile and nonextractable. Acrylic melamine and acrylic urethane coatings prepared from the polymer-bound light stabilizer resins exhibit outstanding weatherability and durability in both accelerated and outdoor weathering.

  4. Influence of Sea Water Aging on the Mechanical Behaviour of Acrylic Matrix Composites

    NASA Astrophysics Data System (ADS)

    Davies, P.; Le Gac, P.-Y.; Le Gall, M.

    2016-07-01

    A new matrix resin was recently introduced for composite materials, based on acrylic resin chemistry allowing standard room temperature infusion techniques to be used to produce recyclable thermoplastic composites. This is a significant advance, particularly for more environmentally-friendly production of large marine structures such as boats. However, for such applications it is essential to demonstrate that composites produced with these resins resist sea water exposure in service. This paper presents results from a wet aging study of unreinforced acrylic and glass and carbon fibre reinforced acrylic composites. It is shown that the acrylic matrix resin is very stable in seawater, showing lower property losses after seawater aging than those of a commonly-used epoxy matrix resin. Carbon fibre reinforced acrylic also shows good property retention after aging, while reductions in glass fibre reinforced composite strengths suggest that specific glass fibre sizing may be required for optimum durability.

  5. Fabrication of Closed Hollow Bulb Obturator Using Thermoplastic Resin Material.

    PubMed

    Shrestha, Bidhan; Hughes, E Richard; Kumar Singh, Raj; Suwal, Pramita; Parajuli, Prakash Kumar; Shrestha, Pragya; Sharma, Arati; Adhikari, Galav

    2015-01-01

    Purpose. Closed hollow bulb obturators are used for the rehabilitation of postmaxillectomy patients. However, the time consuming process, complexity of fabrication, water leakage, and discoloration are notable disadvantages of this technique. This paper describes a clinical report of fabricating closed hollow bulb obturator using a single flask and one time processing method for an acquired maxillary defect. Hard thermoplastic resin sheet has been used for the fabrication of hollow bulb part of the obturator. Method. After fabrication of master cast conventionally, bulb and lid part of the defect were formed separately and joined by autopolymerizing acrylic resin to form one sized smaller hollow body. During packing procedure, the defect area was loaded with heat polymerizing acrylic resin and then previously fabricated smaller hollow body was adapted over it. The whole area was then loaded with heat cure acrylic. Further processes were carried out conventionally. Conclusion. This technique uses single flask which reduces laboratory time and makes the procedure simple. The thickness of hollow bulb can be controlled and light weight closed hollow bulb prosthesis can be fabricated. It also minimizes the disadvantages of closed hollow bulb obturator such as water leakage, bacterial infection, and discoloration.

  6. Fabrication of Closed Hollow Bulb Obturator Using Thermoplastic Resin Material

    PubMed Central

    Shrestha, Bidhan; Hughes, E. Richard; Kumar Singh, Raj; Suwal, Pramita; Parajuli, Prakash Kumar; Shrestha, Pragya; Sharma, Arati; Adhikari, Galav

    2015-01-01

    Purpose. Closed hollow bulb obturators are used for the rehabilitation of postmaxillectomy patients. However, the time consuming process, complexity of fabrication, water leakage, and discoloration are notable disadvantages of this technique. This paper describes a clinical report of fabricating closed hollow bulb obturator using a single flask and one time processing method for an acquired maxillary defect. Hard thermoplastic resin sheet has been used for the fabrication of hollow bulb part of the obturator. Method. After fabrication of master cast conventionally, bulb and lid part of the defect were formed separately and joined by autopolymerizing acrylic resin to form one sized smaller hollow body. During packing procedure, the defect area was loaded with heat polymerizing acrylic resin and then previously fabricated smaller hollow body was adapted over it. The whole area was then loaded with heat cure acrylic. Further processes were carried out conventionally. Conclusion. This technique uses single flask which reduces laboratory time and makes the procedure simple. The thickness of hollow bulb can be controlled and light weight closed hollow bulb prosthesis can be fabricated. It also minimizes the disadvantages of closed hollow bulb obturator such as water leakage, bacterial infection, and discoloration. PMID:26491575

  7. The analysis of colored acrylic, cotton, and wool textile fibers using micro-Raman spectroscopy. Part 2: comparison with the traditional methods of fiber examination.

    PubMed

    Buzzini, Patrick; Massonnet, Genevieve

    2015-05-01

    In the second part of this survey, the ability of micro-Raman spectroscopy to discriminate 180 fiber samples of blue, black, and red cottons, wools, and acrylics was compared to that gathered with the traditional methods for the examination of textile fibers in a forensic context (including light microscopy methods, UV-vis microspectrophotometry and thin-layer chromatography). This study shows that the Raman technique plays a complementary and useful role to obtain further discriminations after the application of light microscopy methods and UV-vis microspectrophotometry and assure the nondestructive nature of the analytical sequence. These additional discriminations were observed despite the lower discriminating powers of Raman data considered individually, compared to those of light microscopy and UV-vis MSP. This study also confirms that an instrument equipped with several laser lines is necessary for an efficient use as applied to the examination of textile fibers in a forensic setting. PMID:25731068

  8. Surface grafted chitosan gels. Part I. Molecular insight into the formation of chitosan and poly(acrylic acid) multilayers.

    PubMed

    Liu, Chao; Thormann, Esben; Claesson, Per M; Tyrode, Eric

    2014-07-29

    Composite polyelectrolyte multilayers of chitosan and low molecular weight poly(acrylic acid) (PAA) have been assembled by sequential adsorption as a first step toward building a surface anchored chitosan gel. Silane chemistry was used to graft the first chitosan layer to prevent film detachment and decomposition. The assembly process is characterized by nonlinear growth behavior, with different adsorption kinetics for chitosan and PAA. In situ analysis of the multilayer by means of surface sensitive total internal reflection Raman (TIRR) spectroscopy, combined with target factor analysis of the spectra, provided information regarding composition, including water content, and ionization state of weak acidic and basic groups present in the thin composite film. Low molecular weight PAA, mainly in its protonated form, diffuses into and out of the composite film during adsorption and rinsing steps. The higher molecular weight chitosan shows a similar behavior, although to a much lower extent. Our data demonstrate that the charged monomeric units of chitosan are mainly compensated by carboxylate ions from PAA. Furthermore, the morphology and mechanical properties of the multilayers were investigated in situ using atomic force microscopy operating in PeakForce tapping mode. The multilayer consists of islands that grow in lateral dimension and height during the build-up process, leading to close to exponentially increasing roughness with deposition number. Both diffusion in and out of at least one of the two components (PAA) and the island-like morphology contribute to the nonlinear growth of chitosan/PAA multilayers.

  9. Modified resin--intermediate processing of perovskite powders:Part I. Optimization of polymeric precursors

    SciTech Connect

    Tai, L. ); Lessing, P.A. )

    1992-02-01

    The formation of a polyester between citric acid (CA) and ethylene glycol (EG) was found to be a decisive factor for the foaming of resin intermediates in a Pechini-type powder process. This process was modified by changing the organic mass ratio of CA/EG which results in ceramic powders with different morphologies. The most porous resin intermediate (with or without chelated cations) was prepared using a polymeric gel made of equimolar citric acid and ethylene glycol. It was also found that a premixing of organic components, prior to adding constituent nitrate solutions, makes the whole process more controllable.

  10. MexAB-OprM specific efflux pump inhibitors in Pseudomonas aeruginosa. Part 4: Addressing the problem of poor stability due to photoisomerization of an acrylic acid moiety.

    PubMed

    Nakayama, Kiyoshi; Kuru, Noriko; Ohtsuka, Masami; Yokomizo, Yoshihiro; Sakamoto, Atsunobu; Kawato, Haruko; Yoshida, Ken-ichi; Ohta, Toshiharu; Hoshino, Kazuki; Akimoto, Katsuya; Itoh, Junko; Ishida, Hiroko; Cho, Aesop; Palme, Monica H; Zhang, Jason Z; Lee, Ving J; Watkins, William J

    2004-05-17

    Exchange of the ethylene tether in a series of pyridopyrimidine-based MexAB-OprM specific efflux pump inhibitors to an amide bond stabilized the olefin of the acrylic acid moiety, preventing facile photoisomerization to the Z-isomer. Furthermore, the activity was drastically improved in the amide tether variants, providing extremely potent acrylic acid and vinyl tetrazole analogues.

  11. Ester-free Thiol-ene Dental Restoratives – Part A: Resin Development

    PubMed Central

    Podgórski, Maciej; Becka, Eftalda; Claudino, Mauro; Flores, Alexander; Shah, Parag K.; Stansbury, Jeffrey W.; Bowman, Christopher N.

    2015-01-01

    Objectives To detail the development of ester-free thiol-ene dental resins with enhanced mechanical performance, limited potential for water uptake/leachables/degradation and low polymerization shrinkage stress. Methods Thiol-terminated oligomers were prepared via a thiol-Michael reaction and a bulky tetra-allyl monomer containing urethane linkages was synthesized. The experimental oligomers and/or monomers were photopolymerized using visible light activation. Several thiol-ene formulations were investigated and their performance ranked by comparisons of the thermo-mechanical properties, polymerization shrinkage stress, water sorption/solubility, and reactivity with respect to a control comprising a conventional BisGMA/TEGDMA dental resin. Results The ester-free thiol-ene formulations had significantly lower viscosities, water sorption and solubility than the BisGMA/TEGDMA control. Depending on the resin, the limiting functional conversions were equivalent to or greater than that of BisGMA/TEGDMA. At comparable conversions, lower shrinkage stress values were achieved by the thiol-ene systems. The polymerization shrinkage stress was dramatically reduced when the tetra-allyl monomer was used as the ene in ester-free thiol-ene mixtures. Although exhibiting lower Young’s modulus, flexural strength, and glass transition temperatures, the toughness values associated with thiol-ene resins were greater than that of the BisGMA/TEGDMA control. In addition, the thiol-ene polymerization resulted in highly uniform polymer networks as indicated by the narrow tan delta peak widths. Significance Employing the developed thiol-ene resins in dental composites will reduce shrinkage stress and moisture absorption and form tougher materials. Furthermore, their low viscosities are expected to enable higher loadings of functionalized micro/nano-scale filler particles relevant for practical dental systems. PMID:26360013

  12. Resin-retained bridges re-visited. Part 2. Clinical considerations.

    PubMed

    St George, Geoffrey; Hemmings, Ken; Patel, Kalpesh

    2002-10-01

    Resin-retained bridges have been used clinically since the 1970s, and offer a more conservative approach to the restoration of edentulous spaces than conventional bridgework. They are easy to place, cheap to fabricate and have been shown to be cost-effective. Despite this, they are not frequently used in general dental practice and they have an undeserved reputation for failure. Since their initial introduction, they have undergone a number of changes to their method of retention, and the materials used in their construction. This has resulted in a predictable, aesthetic restoration which, barring the use of implants, is often the treatment of choice where teeth adjacent to an edentulous space are minimally or not restored. This article hopes to show the clinical techniques required to produce predictable resin-retained bridgework in general practice. PMID:12483790

  13. Selection of di(meth)acrylate monomers for low pollution of fluorinated mold surfaces in ultraviolet nanoimprint lithography.

    PubMed

    Nakagawa, Masaru; Kobayashi, Kei; Hattori, Azusa N; Ito, Shunya; Hiroshiba, Nobuya; Kubo, Shoichi; Tanaka, Hidekazu

    2015-04-14

    We used fluorescence microscopy to show that low adsorption of resin components by a mold surface was necessary for continuous ultraviolet (UV) nanoimprinting, as well as generation of a low release energy on detachment of a cured resin from a template mold. This is because with low mold pollution, fracture on demolding occurred at the interface between the mold and cured resin surfaces rather than at the outermost part of the cured resin. To achieve low mold pollution, we investigated the radical photopolymerization behaviors of fluorescent UV-curable resins and the mechanical properties (fracture toughness, surface hardness, and release energy) of the cured resin films for six types of di(meth)acrylate-based monomers with similar chemical structures, in which polar hydroxy and aromatic bulky bisphenol moieties and methacryloyl or acryloyl reactive groups were present or absent. As a result, we selected bisphenol A glycerolate dimethacrylate (BPAGDM), which contains hydroxy, bisphenol, and methacryloyl moieties, which give good mechanical properties, monomer bulkiness, and mild reactivity, respectively, as a suitable base monomer for UV nanoimprinting under an easily condensable alternative chlorofluorocarbon (HFC-245fa) atmosphere. The fluorescent UV-curable BPAGDM resin was used for UV nanoimprinting and lithographic reactive ion etching of a silicon surface with 32 nm line-and-space patterns without a hard metal layer. PMID:25793911

  14. In-situ property measurements on laser-drawn strands of SL 5170 epoxy and SL 5149 acrylate

    SciTech Connect

    Guess, T.R.; Chambers, R.S.

    1995-08-01

    Material behavior plays a significant role in the mechanics leading to internal stresses and, potentially, to distortion (curling) of parts as they are built by stereolithography processes that utilize photocuring resins. A study is underway to generate material properties that can be used to develop phenomenological material models of epoxy and acrylate resins. Strand tests are performed in situ in a 3D System`s SLA-250 machine; strands are drawn by either single or multiple exposures of the resin to a laser beam. Linear shrinkage, cross-sectional areas, cure shrinkage forces and stress-strain data are presented. Also, the curl in cantilever beam specimens, built with different draw patterns, are compared.

  15. Acrylate Systemic Contact Dermatitis.

    PubMed

    Sauder, Maxwell B; Pratt, Melanie D

    2015-01-01

    Acrylates, the 2012 American Contact Dermatitis Society allergen of the year, are found in a range of products including the absorbent materials within feminine hygiene pads. When fully polymerized, acrylates are nonimmunogenic; however, if not completely cured, the monomers can be potent allergens.A 28-year-old woman is presented, who had her teeth varnished with Isodan (Septodont, Saint-Maur-des-Fossés, France) containing HEMA (2-hydroxyethyl methacrylate) with no initial reaction. Approximately 1 month later, the patient developed a genital dermatitis secondary to her feminine hygiene pads. The initial reaction resolved, but 5 months later, the patient developed a systemic contact dermatitis after receiving a second varnishing.The patient was dramatically patch test positive to many acrylates. This case demonstrates a reaction to likely unpolymerized acrylates within a feminine hygiene pad, as well as broad cross-reactivity or cosensitivity to acrylates, and possibly a systemic contact dermatitis with systemic re-exposure to unpolymerized acrylates.

  16. Dimensional stability of denture bases following repair with microwave resin.

    PubMed

    Dyer, R A; Howlett, J A

    1994-08-01

    The dimensional stability of a commercially available acrylic resin, designed specifically for polymerization by microwave irradiation, was compared with that of a conventional water-bath-cured resin. Resin bases were processed on duplicate stone casts prepared from a cobalt chromium master die. Twenty bases were polymerized, using acrylic resin modified for rapid heat curing, in a water-bath at 100 degrees C for 22 min. A further 20 bases were polymerized using a microwave curing acrylic resin, in a conventional microwave oven at 500 W power output for 3 min. Ten bases from each group were sectioned in a parasagittal direction and repaired using the microwave curing resin. Following each curing cycle the fit of the posterior border of each base was evaluated via a silicone index formed between the base and the master die. The index was invested in stone and sectioned through the posterior palatal region to allow measurement of its thickness by means of an eyepiece micrometer. One-way analysis of variance and unpaired Student's t tests were employed to compare the differences in distortion at the initial cure and following repair. No significant differences were found in the distortion of the acrylic resin bases produced from the heat-cured or microwave-cured materials. All bases exhibited significant further distortion on repair with the microwave-cured acrylic resin.

  17. Advances in acrylic-alkyd hybrid synthesis and characterization

    NASA Astrophysics Data System (ADS)

    Dziczkowski, Jamie

    2008-10-01

    In situ graft acrylic-alkyd hybrid resins were formed by polymerizing acrylic and acrylic-mixed monomers in the presence of alkyds by introduction of a free radical initiator to promote graft formation. Two-dimensional NMR, specifically gradient heteronuclear multiple quantum coherence (gHMQC), was used to clarify specific graft sites of the hybrid materials. Both individual and mixed-monomer systems were produced to determine any individual monomer preferences and to model current acrylic-alkyd systems. Different classes of initiators were used to determine any initiator effects on graft location. The 2D-NMR results confirm grafting at doubly allylic hydrogens located on the fatty acid chains and the polyol segment of the alkyd backbone. The gHMQC spectra show no evidence of grafting across double bonds on either pendant fatty acid groups or THPA unsaturation sites for any of the monomer or mixed monomer systems. It was also determined that choice of initiator has no effect on graft location. In addition, a design of experiments using response surface methodology was utilized to obtain a better understanding of this commercially available class of materials and relate both the chemical and physical properties to one another. A Box-Behnkin design was used, varying the oil length of the alkyd phase, the degree of unsaturation in the polyester backbone, and acrylic to alkyd ratio. Acrylic-alkyd hybrid resins were reduced with an amine/water mixture. Hydrolytic stability was tested and viscoelastic properties were obtained to determine crosslink density. Cured films were prepared and basic coatings properties were evaluated. It was found that the oil length of the alkyd is the most dominant factor for final coatings properties of the resins. Acrylic to alkyd ratio mainly influences the resin properties such as acid number, average molecular weight, and hydrolytic stability. The degree of unsaturation in the alkyd backbone has minimal effects on resin and film

  18. Technical Task and Quality Assurance Plan in Support of BNFL Part B: Studies of Ion Exchange Resin Integrity under Flowsheet Extremes: Part II

    SciTech Connect

    Nash, C.A.

    2000-08-23

    This task will address four items related to ion exchange stability: (1) process upset evaluation of resin in contact with 1 molar sodium permanganate at 25 and 40 degrees C, (2) accelerated aging with nitric acid solution used during normal regeneration operations, (3) prolonged contacting of SuperLig 644 resin with 5 molar nitric acid at room temperature, and (4) prolonged contacting of SuperLig 644 resin with deionized water at 60 plus/minus 5 degrees C.

  19. Quantitation of buried contamination by use of solvents. Part 1: Solvent degradation of amine cured epoxy resins

    NASA Technical Reports Server (NTRS)

    Rheineck, A. E.; Heskin, R. A.; Hill, L. W.

    1972-01-01

    The solubility and/or swelling of cured epoxy resins was studied using the solubility parameter method. Determination of solubility parameters were found in order to select solvents for solvent-assisted degradation of cured epoxy polymers used in spacecraft. A method for improving recovery of seeded spores is suggested for assay of buried contaminants. Three commercial epoxy resins were cured using four different alkyl amines. For each resin-amine combination, three levels of amine were used, corresponding to 1/3, 2/3, and all of the amine required to react with the oxirane groups of the resin. The solubility parameters of the 36 resulting model compounds were determined in poorly and moderately hydrogen-bonded solvents. No strongly hydrogen-bonded solvents caused dissolution or swelling. The tolerance of cured resins is discussed in terms of polymer structure.

  20. Preparation and properties of UV curable acrylic PSA by vinyl bonded graphene oxide

    NASA Astrophysics Data System (ADS)

    Pang, Beili; Ryu, Chong-Min; Jin, Xin; Kim, Hyung-Il

    2013-11-01

    Acrylic pressure sensitive adhesives (PSAs) with higher thermal stability for thin wafer handling were successfully prepared by forming composite with the graphene oxide (GO) nanoparticles modified to have vinyl groups via subsequent reaction with isophorone diisocyanate and 2-hydroxyethyl methacrylate. The acrylic copolymer was synthesized as a base resin for PSAs by solution radical polymerization of ethyl acrylate, 2-ethylhexyl acrylate, and acrylic acid followed by further modification with GMA to have the vinyl groups available for UV curing. The peel strength of PSA decreased with the increase of gel content which was dependent on both modified GO content and UV dose. Thermal stability of UV-cured PSA was improved noticeably with increasing the modified GO content mainly due to the strong and extensive interfacial bonding formed between the acrylic copolymer matrix and GO fillers

  1. Comparison of XAD macroporous resins for the concentration of fulvic acid from aqueous solution

    USGS Publications Warehouse

    Aiken, G.R.

    1979-01-01

    Five macroreticular, nonlonlc AmberlHe XAD resins were evaluated for concentration and Isolation of fulvlc acid from aqueous solution. The capacity of each resin for fulvlc acid was measured by both batch and column techniques. Elution efficiencies were determined by desorptlon with 0.1 N NaOH. Highest recoveries were obtained with the acrylic ester resins which proved to be most efficient for both adsorption and elution of fulvlc acid. Compared to the acrylic ester resins, usefulness of the styrene dvlnybenzene resins to remove fulvlc acid is limited because of slow diffusion-controlled adsorption and formation of charge-transfer complexes, which hinders elution. ?? 1979 American Chemical Society.

  2. Effect of the processing cycle on dimensional changes of heat-polymerized denture base resins

    PubMed Central

    Savabi, Ghazal; Savabi, Omid; Dastgheib, Badrosadat; Nejatidanesh, Farahnaz

    2015-01-01

    Background: The second processing cycle for adding the artificial teeth to heat-polymerized acrylic resin denture bases may result in dimensional changes of the denture bases. The aim of this study was to evaluate the dimensional changes of the heat-polymerized acrylic resin denture bases with one and two-cycle processing methods. Materials and Methods: A metal edentulous maxillary arch was used for making 40 stone casts. Maxillary complete dentures were made with heat-polymerized acrylic resins (Meliodent and Acropars) with one and two stage processing methods (n = 10 for each group). Linear dimensional changes in anteroposterior and mediolateral distances and vertical changes in the first molar region were measured following each processing cycle, using a digital caliper. Mean percentage of the dimensional changes were subjected to two-way analysis of variance and Tukey honest significant difference tests (α = 0.05). Results: Postpolymerization contraction occurred in both anteroposterior and mediolateral directions in all studied groups; however, the vertical dimension was increased. Acropars acrylic resin showed the highest dimensional changes and the second processing cycle significantly affected the measured distances (P < 0.05). Meliodent acrylic resin was not significantly influenced by the processing method. Conclusion: Reheating of the acrylic resin denture bases for the addition of denture teeth result in linear dimensional changes, which can be clinically significant based on the acrylic resin used. PMID:26288618

  3. ICI/BASF PP for acrylics swap

    SciTech Connect

    Alperowicz, N.

    1993-01-27

    ICI (London) and BASF (Ludwigshafen) have announced their long-awaited polypropylene (PP) for acrylics swap deal. ICI is buying BASF's European acrylic resin business, and the German firm will acquire ICI's European PP operations. The deal is due for completion by mid-1993, subject to regulatory approvals. BASF, hitherto a small-scale PP producer, doubles capacity to 600,000 m.t./year and moves up the European PP league to number three, behind Himont and Shell. BASF, whose process is used in the plants, secures a foothold in the UK PP market, where Shell - planning a merger with Himont - is the only other producer, with 170,000 m.t./year. ICI's purchase involves BASF's Resart GmbH and Critesa SA subsidiaries, located at Mainz, Germany and near Barcelona, Spain, respectively. The business - which will add about [Brit pounds]60 million ($93 million) to ICI Acrylics [Brit pounds]300-million revenues - employs 400 people, who will transfer to ICI.

  4. Acrylic vessel cleaning tests

    SciTech Connect

    Earle, D.; Hahn, R.L.; Boger, J.; Bonvin, E.

    1997-02-26

    The acrylic vessel as constructed is dirty. The dirt includes blue tape, Al tape, grease pencil, gemak, the glue or residue form these tapes, finger prints and dust of an unknown composition but probably mostly acrylic dust. This dirt has to be removed and once removed, the vessel has to be kept clean or at least to be easily cleanable at some future stage when access becomes much more difficult. The authors report on the results of a series of tests designed: (a) to prepare typical dirty samples of acrylic; (b) to remove dirt stuck to the acrylic surface; and (c) to measure the optical quality and Th concentration after cleaning. Specifications of the vessel call for very low levels of Th which could come from tape residues, the grease pencil, or other sources of dirt. This report does not address the concerns of how to keep the vessel clean after an initial cleaning and during the removal of the scaffolding. Alconox is recommended as the cleaner of choice. This acrylic vessel will be used in the Sudbury Neutrino Observatory.

  5. Acrylic purification and coatings

    NASA Astrophysics Data System (ADS)

    Kuźniak, Marcin

    2011-04-01

    Radon (Rn) and its decay daughters are a well-known source of background in direct WIMP detection experiments, as either a Rn decay daughter or an alpha particle emitted from a thin inner surface layer of a detector could produce a WIMP-like signal. Different surface treatment and cleaning techniques have been employed in the past to remove this type of contamination. A new method of dealing with the problem has been proposed and used for a prototype acrylic DEAP-1 detector. Inner surfaces of the detector were coated with a layer of ultra pure acrylic, meant to shield the active volume from alphas and recoiling nuclei. An acrylic purification technique and two coating techniques are described: a solvent-borne (tested on DEAP-1) and solvent-less (being developed for the full scale DEAP-3600 detector).

  6. Acrylic purification and coatings

    SciTech Connect

    Kuzniak, Marcin

    2011-04-27

    Radon (Rn) and its decay daughters are a well-known source of background in direct WIMP detection experiments, as either a Rn decay daughter or an alpha particle emitted from a thin inner surface layer of a detector could produce a WIMP-like signal. Different surface treatment and cleaning techniques have been employed in the past to remove this type of contamination. A new method of dealing with the problem has been proposed and used for a prototype acrylic DEAP-1 detector. Inner surfaces of the detector were coated with a layer of ultra pure acrylic, meant to shield the active volume from alphas and recoiling nuclei. An acrylic purification technique and two coating techniques are described: a solvent-borne (tested on DEAP-1) and solvent-less (being developed for the full scale DEAP-3600 detector).

  7. Immunomicroscopy: resin techniques and on-section labelling with immunocolloidal gold or immunoperoxidase--planning a protocol.

    PubMed

    Hobot, J A; Newman, G R

    1996-01-01

    On-section immunocytochemistry is divided into two parts: (i) processing of biological tissue for section microscopy and (ii) immunolabelling of sections. Many of the more successful microscopical methods employ delicate aldehyde fixation of biological tissue followed by "sympathetic" processing into an acrylic resin. Processing regimens do not have to be complicated. Simple and cost effective room temperature protocols utilising partial dehydration have been devised and they can be as effective as the more complex low temperature techniques in preserving both ultrastructure and antigenic reactivity. The embedded material can be investigated by either light or electron microscopy. Frozen sections can be cut and immunolabelled but only if the tissue is chemically fixed first, as in resin embedding. Fixation with low concentrations of aldehyde will normally better preserve tissue immunoreactivity but this may be at the expense of good ultrastructure with these protocols. If so, low temperature resin embedding methods or rapid freezing and cryosubstitution can be tried. The choice of processing protocol will determine which acrylic resin to use, as will the preference for subsequent immunolabelling with either colloidal gold or peroxidase/diaminobenzidine (DAB). Both types of labelling system offer advantages to localisation studies and can be used in combination for double or even triple labelling. Silver enhancement of the colloidal gold or DAB allows for improved observation by light microscopy.

  8. Characteristics of denture thermoplastic resins for non-metal clasp dentures.

    PubMed

    Takabayashi, Yota

    2010-08-01

    Six thermoplastic resins and conventional acrylic resin were examined to characterize their mechanical and physical properties, water sorption, solubility, flexural strength, modulus of elasticity, tensile strength and color stability. Thermoplastic resins for non-metal clasp dentures exhibiting low water sorption and solubility offer hygienic advantages. Since they have a low modulus of elasticity and are easily manipulated, these materials make it possible for larger undercuts to be used for retention compared to acrylic resin. Not all of the thermoplastic resins tested fractured after the bending test in contrast to the conventional denture base resin, which fractured when tested beyond its proportional limit. It was also found that clinically noticeable staining may occur on the polyamide resins and polyethylene terephtalate resins. PMID:20644329

  9. Use of acrylic sheet molds for elastomeric products

    NASA Technical Reports Server (NTRS)

    Heisman, R. M.; Koerner, A. E.; Messineo, S. M.

    1970-01-01

    Molds constructed of acrylic sheet are more easily machined than metal, are transparent to ensure complete filling during injection, and have smooth surfaces free of contamination. Technique eliminates flashing on molded parts and mold release agents.

  10. Acrylic mechanical bond tests

    SciTech Connect

    Wouters, J.M.; Doe, P.J.

    1991-02-01

    The tensile strength of bonded acrylic is tested as a function of bond joint thickness. 0.125 in. thick bond joints were found to posses the maximum strength while the acceptable range of joints varied from 0.063 in. to almost 0.25 in. Such joints are used in the Sudbury Neutrino Observatory.

  11. Toughened epoxy resins: Preformed particles as tougheners for adhesives and matrices

    SciTech Connect

    Riew, C.K.; Siebert, A.R.; Smith, R.W.

    1996-12-31

    Free-flowing,preformed,rigid,multilayer acrylic core-shell polymers were used to enhance the toughness of epoxy resins. The glass transition temperatures of the cured epoxys were over 190 degrees centigrade.

  12. Thermally stable laminating resins

    NASA Technical Reports Server (NTRS)

    Jones, R. J.; Vaughan, R. W.; Burns, E. A.

    1972-01-01

    Improved thermally stable laminating resins were developed based on the addition-type pyrolytic polymerization. Detailed monomer and polymer synthesis and characterization studies identified formulations which facilitate press molding processing and autoclave fabrication of glass and graphite fiber reinforced composites. A specific resin formulation, termed P10P was utilized to prepare a Courtaulds HMS reinforced simulated airfoil demonstration part by an autoclave molding process.

  13. Mechanism of gas permeation through polymer membranes. Part I. Pure gases. Comprehensive progress report. [Polybutadiene, poly(vinyl acetate), poly(methyl acrylate)

    SciTech Connect

    Stern, S.A.; Kulkarni, S.S.; Mauze, G.R.

    1982-07-01

    The objective of this study is to assess the validity of a free-volume model of gas permeation through nonporous polymer membranes. This model provides a formalism for the prediction of permeability coefficients for pure gaseous penetrants and their mixtures as a function of both pressure and temperature. Such information is of great importance for the development of new, energy-efficient membrane processes for the separation of gas mixtures. Diffusion and solubility coefficients for Ar, CO/sub 2/, CH/sub 4/, C/sub 2/H/sub 4/, C/sub 3/H/sub 8/, and SF/sub 6/ in polyethylene membranes and rods have been measured in the temperature range from 5/sup 0/ to 50/sup 0/C and at pressures up to 40 atm. under isothermal-isobaric conditions. It was found that the dependence of the diffusion and permeability coefficients on penetrant gas pressure and on temperature is satisfactorily represented by Fujita's free-volume model for the transport of small molecules in polymers and by its extension to gas permeation. The free-volume model of gas permeation relates permeability coefficients for gases in polymers to three thermodynamic variables, namely, temperature, pressure, and penetrant concentration, and to three characteristic parameters denoted A/sub d/, B/sub d/, and ..gamma... Semi-empirical correlations were developed for these parameters as a function of physicochemical properties of the penetrant and the polymer. These correlations were obeyed by the gas-polyethylene systems studied in the present work. A generalized correlation was found for B/sub d/ values of penetrants of various molecular sizes in polyethylene, polybutadiene, poly(vinyl acetate), poly(methyl acrylate), silicone rubber, and natural rubber.

  14. Commercial Ion Exchange Resin Vitrification in Borosilicate Glass

    SciTech Connect

    Cicero-Herman, C.A.; Workman, P.; Poole, K.; Erich, D.; Harden, J.

    1998-05-01

    Bench-scale studies were performed to determine the feasibility of vitrification treatment of six resins representative of those used in the commercial nuclear industry. Each resin was successfully immobilized using the same proprietary borosilicate glass formulation. Waste loadings varied from 38 to 70 g of resin/100 g of glass produced depending on the particular resin, with volume reductions of 28 percent to 68 percent. The bench-scale results were used to perform a melter demonstration with one of the resins at the Clemson Environmental Technologies Laboratory (CETL). The resin used was a weakly acidic meth acrylic cation exchange resin. The vitrification process utilized represented a approximately 64 percent volume reduction. Glass characterization, radionuclide retention, offgas analyses, and system compatibility results will be discussed in this paper.

  15. Pulse radiolysis of aqueous solutions of ethyl acrylate and hydroxy ethyl acrylate

    NASA Astrophysics Data System (ADS)

    Safrany, A.; Biro, A.; Wojnarovits, L.

    1993-10-01

    Ethyl- and hydroxy ethyl acrylate show high reactivities with hydrated electron and hydroxyl radical intermediates of water radiolysis. The electron adduct reversibly protonate with pK values of 5.7 and 7.3. The adducts may take part in irreversible protonation at the β carbon atom forming α-carboxyl alkyl radicals. Same type of radical forms in reaction of acrylates with OH: at low concentration the adduct mainly disappear in self termination reactions. Above 5 mmol dm -1 the signals showed the startup of oligomerization.

  16. Synthesis of Radiation Curable Palm Oil-Based Epoxy Acrylate: NMR and FTIR Spectroscopic Investigations.

    PubMed

    Salih, Ashraf M; Ahmad, Mansor Bin; Ibrahim, Nor Azowa; Dahlan, Khairul Zaman Hj Mohd; Tajau, Rida; Mahmood, Mohd Hilmi; Yunus, Wan Md Zin Wan

    2015-01-01

    Over the past few decades, there has been an increasing demand for bio-based polymers and resins in industrial applications, due to their potential lower cost and environmental impact compared with petroleum-based counterparts. The present research concerns the synthesis of epoxidized palm oil acrylate (EPOLA) from an epoxidized palm oil product (EPOP) as environmentally friendly material. EPOP was acrylated by acrylic acid via a ring opening reaction. The kinetics of the acrylation reaction were monitored throughout the reaction course and the acid value of the reaction mixture reached 10 mg KOH/g after 16 h, indicating the consumption of the acrylic acid. The obtained epoxy acrylate was investigated intensively by means of FTIR and NMR spectroscopy, and the results revealed that the ring opening reaction was completed successfully with an acrylation yield about 82%. The UV free radical polymerization of EPOLA was carried out using two types of photoinitiators. The radiation curing behavior was determined by following the conversion of the acrylate groups. The cross-linking density and the hardness of the cured EPOLA films were measured to evaluate the effect of the photoinitiator on the solid film characteristics, besides, the thermal and mechanical properties were also evaluated. PMID:26248072

  17. 21 CFR 177.1010 - Acrylic and modified acrylic plastics, semirigid and rigid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acrylic and modified acrylic plastics, semirigid... Acrylic and modified acrylic plastics, semirigid and rigid. Semirigid and rigid acrylic and modified acrylic plastics may be safely used as articles intended for use in contact with food, in accordance...

  18. 21 CFR 177.1010 - Acrylic and modified acrylic plastics, semirigid and rigid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Acrylic and modified acrylic plastics, semirigid... Acrylic and modified acrylic plastics, semirigid and rigid. Semirigid and rigid acrylic and modified acrylic plastics may be safely used as articles intended for use in contact with food, in accordance...

  19. 21 CFR 177.1010 - Acrylic and modified acrylic plastics, semirigid and rigid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Acrylic and modified acrylic plastics, semirigid... Acrylic and modified acrylic plastics, semirigid and rigid. Semirigid and rigid acrylic and modified acrylic plastics may be safely used as articles intended for use in contact with food, in accordance...

  20. Investigation of fluorinated (Meth)acrylate monomers and macromonomers suitable for a hydroxy-containing acrylate monomer in UV nanoimprinting.

    PubMed

    Ito, Shunya; Kaneko, Shu; Yun, Cheol Min; Kobayashi, Kei; Nakagawa, Masaru

    2014-06-24

    We investigated reactive fluorinated (meth)acrylate monomers and macromonomers that caused segregation at the cured resin surface of a viscous hydroxy-containing monomer, glycerol 1,3-diglycerolate diacrylate (GDD), and decreased the demolding energy in ultraviolet (UV) nanoimprinting with spin-coated films under a condensable alternative chlorofluorocarbon gas atmosphere. The X-ray photoelectron spectroscopy and contact angle measurements used to determine the surface free energy suggested that a nonvolatile silicone-based methacrylate macromonomer with fluorinated alkyl groups segregated at the GDD-based cured resin surface and decreased the surface free energy, while fluorinated acrylate monomers hardly decreased the surface free energy because of their evaporation during the annealing of the spin-coated films. The average demolding energy of GDD-based cured resins with the macromonomer having fluorinated alkyl groups was smaller than that with the macromonomer having hydrocarbon alkyl groups. The fluorinated alkyl groups were responsible for decreasing the demolding energy rather than the polysiloxane main chains. We demonstrated that the GDD-based UV-curable resin with the fluorinated silicone-based macromonomer was suitable for step-and-repeat UV nanoimprinting with a bare silica mold, in addition to silica molds treated by chemical vapor surface modification with trifluoro-1,1,2,2-tetrahydropropyltrimethoxysilane (FAS3) and tridecafluoro-1,1,2,2-tetrahydrooctyltrimethoxysilane (FAS13). PMID:24892792

  1. Effect of ultraviolet light irradiation on bonding of experimental composite resin artificial teeth.

    PubMed

    Loyaga-Rendon, Paola G; Takahashi, Hidekazu; Iwasaki, Naohiko; Reza, Fazal

    2007-11-01

    The purpose of the present study was to evaluate how ultraviolet light (UV) irradiation using an ordinary UV sterilizer would affect the bonding of experimental composite resins to an autopolymerizing acrylic resin. To this end, three composite resins and one unfilled resin--of which the compositions were similar to commercial composite resin artificial teeth--were prepared as repair composites. Their shear bond strengths after UV irradiation for one to 60 minutes were significantly greater than those before UV irradiation regardless of composite resin type. Failure mode after UV irradiation for one to 60 minutes was mainly cohesive failure of the composite resins, but that before UV irradiation and after 24 hours' irradiation was mainly adhesive failure. These results thus suggested that a short period of UV irradiation on composite resin teeth would improve the bonding efficacy of composite resin artificial teeth to autopolymerizing resin.

  2. Internal characterization of denture base by using acrylic stains and tissue paper.

    PubMed

    Pattanaik, Seema; Pattanaik, Bikash

    2011-09-01

    Characterization of an artificial denture is required to give the denture a more natural appearance. This article describes the laboratory procedures for internal characterization of denture base in a removable prosthesis using acrylic stains and absorbent tissue paper incorporated in the heat cure polymerizing denture base resin at the stage of packing.

  3. Cationic resins prepared by radiation-induced graft copolymerization

    NASA Astrophysics Data System (ADS)

    Siyam, T.; Youssef, H. A.

    1999-07-01

    Poly(acrylamide-acrylic acid) resin P(PAM-AA) was prepared by gamma radiation-initiated grafting copolymerization of acrylic acid (AA) on polyacrylamide (PAM) by addition of Mohr's salt as an inhibitor for homopolymerization. The polymerization was studied at different absorbed doses, polymor/monomer ratios and the monomer concentrations. The grafting percentage increases by increasing the dose and the monomer concentration and decreases by increasing polymer/monomer ratio. There is no significant change in the swelling degree of the obtained resin. It was found that the capacity of the resins towards Cu 2+ increases with increasing the monomer concentration and decreases by increasing the polymer/monomer ratio. The capacity of the resin was found to be constant at all doses.

  4. Technology and the use of acrylics for provisional dentine protection.

    PubMed

    Kapusevska, Biljana; Dereban, Nikola; Popovska, Mirjana; Nikolovska, Julijana; Radojkova Nikolovska, Vеrа; Zabokova Bilbilova, Efka; Mijoska, Aneta

    2013-01-01

    Acrylics are compounds polymerized from monomers of acrylic, metacrylic acid or acrylonitrates. The purpose of this paper is to present the technology and use of acrylics for provisional dentine protection in the practice of dental prosthodontics. For this reason, we followed 120 clinical cases from the everyday clinical practice, divided into 4 groups of 30 patients who needed prosthetic reconstruction. The first group included cases in which we applied celluloid crowns for dentine protection, for the second group we used acrylic teeth from a set of teeth for complete dentures; in the third and fourth groups the fabrication was done with the system of an impression matrix and the acrylic resin block technique respectively. In all the examined patients, the gingival index by Silness and Loe and the vitality of the dental pulp were verified clinically, after preparation and 8 days from the placement of the provisional crown. The value for dental sensitivity measured after preparation was 2.59, and 8 days after the placement of the provisional crown it bwas 3.1. From these results we can conclude that after the 8th day from the placement of the provisional crown, there was an adaptation period, characterized by a decrease in the painful sensations. The value of the Silness and Loe gingival index measured after the preparation was 1.34, and 8 days from the placement of the provisional crown was 0.94. The results inclined us to the fact that the provisional acrylic crowns facilitated the reparation of the periodontal tissue. PMID:24566021

  5. Chemical resistance of optical plastics and resin for level detectors

    NASA Astrophysics Data System (ADS)

    Omegna, Cicero L.; Fontes Garcia, Jonas; Ramos-Gonzáles, Roddy E.; Barbosa, Luiz C.

    2015-09-01

    A test method was developed to find the ideal optical material that supports the chemical reaction of some fuels. Optical plastics and resin were submerged for long periods of time in reservoirs of ethanol, gasoline, Diesel and biodiesel. The dimensional change and weight change of the submerged samples was measured. A special resin successfully supported the chemical attack of fuels. Samples of acrylic polymer and polycarbonate were used as type of optical plastic.

  6. The acrylic tooth-denture base bond: effect of mechanical preparation and surface treatment.

    PubMed

    Adeyemi, Adejumoke Adeola; Lyons, Mervyn Frederick; Cameron, Donald Alexander

    2007-09-01

    The bond strength of acrylic teeth to denture base resins was tested using a widely-accepted technique. The pre-treatments included abrading and grooving the teeth, the application of monomer and the application of a proprietary bonding agent. Each of the 360 specimens was tensile-tested until fracture, using a universal testing machine. When bonded to heat-cured resin, the grooved teeth had the highest mean bond strength while the grooved monomer-treated group had the lowest. When bonded to cold cure resin, the unabraded monomer-treated teeth had the highest mean bond strength and the unabraded group the lowest.

  7. The Reinforcement Effect of Nano-Zirconia on the Transverse Strength of Repaired Acrylic Denture Base.

    PubMed

    Gad, Mohammed; ArRejaie, Aws S; Abdel-Halim, Mohamed Saber; Rahoma, Ahmed

    2016-01-01

    Objective. The aim of this study was to evaluate the effect of incorporation of glass fiber, zirconia, and nano-zirconia on the transverse strength of repaired denture base. Materials and Methods. Eighty specimens of heat polymerized acrylic resin were prepared and randomly divided into eight groups (n = 10): one intact group (control) and seven repaired groups. One group was repaired with autopolymerized resin while the other six groups were repaired using autopolymerized resin reinforced with 2 wt% or 5 wt% glass fiber, zirconia, or nano-zirconia particles. A three-point bending test was used to measure the transverse strength. The results were analyzed using SPSS and repeated measure ANOVA and post hoc least significance (LSD) test (P ≤ 0.05). Results. Among repaired groups it was found that autopolymerized resin reinforced with 2 or 5 wt% nano-zirconia showed the highest transverse strength (P ≤ 0.05). Repairs with autopolymerized acrylic resin reinforced with 5 wt% zirconia showed the lowest transverse strength value. There was no significant difference between the groups repaired with repair resin without reinforcement, 2 wt% zirconia, and glass fiber reinforced resin. Conclusion. Reinforcing of repair material with nano-zirconia may significantly improve the transverse strength of some fractured denture base polymers.

  8. The Reinforcement Effect of Nano-Zirconia on the Transverse Strength of Repaired Acrylic Denture Base

    PubMed Central

    ArRejaie, Aws S.; Abdel-Halim, Mohamed Saber; Rahoma, Ahmed

    2016-01-01

    Objective. The aim of this study was to evaluate the effect of incorporation of glass fiber, zirconia, and nano-zirconia on the transverse strength of repaired denture base. Materials and Methods. Eighty specimens of heat polymerized acrylic resin were prepared and randomly divided into eight groups (n = 10): one intact group (control) and seven repaired groups. One group was repaired with autopolymerized resin while the other six groups were repaired using autopolymerized resin reinforced with 2 wt% or 5 wt% glass fiber, zirconia, or nano-zirconia particles. A three-point bending test was used to measure the transverse strength. The results were analyzed using SPSS and repeated measure ANOVA and post hoc least significance (LSD) test (P ≤ 0.05). Results. Among repaired groups it was found that autopolymerized resin reinforced with 2 or 5 wt% nano-zirconia showed the highest transverse strength (P ≤ 0.05). Repairs with autopolymerized acrylic resin reinforced with 5 wt% zirconia showed the lowest transverse strength value. There was no significant difference between the groups repaired with repair resin without reinforcement, 2 wt% zirconia, and glass fiber reinforced resin. Conclusion. Reinforcing of repair material with nano-zirconia may significantly improve the transverse strength of some fractured denture base polymers. PMID:27366150

  9. The Reinforcement Effect of Nano-Zirconia on the Transverse Strength of Repaired Acrylic Denture Base.

    PubMed

    Gad, Mohammed; ArRejaie, Aws S; Abdel-Halim, Mohamed Saber; Rahoma, Ahmed

    2016-01-01

    Objective. The aim of this study was to evaluate the effect of incorporation of glass fiber, zirconia, and nano-zirconia on the transverse strength of repaired denture base. Materials and Methods. Eighty specimens of heat polymerized acrylic resin were prepared and randomly divided into eight groups (n = 10): one intact group (control) and seven repaired groups. One group was repaired with autopolymerized resin while the other six groups were repaired using autopolymerized resin reinforced with 2 wt% or 5 wt% glass fiber, zirconia, or nano-zirconia particles. A three-point bending test was used to measure the transverse strength. The results were analyzed using SPSS and repeated measure ANOVA and post hoc least significance (LSD) test (P ≤ 0.05). Results. Among repaired groups it was found that autopolymerized resin reinforced with 2 or 5 wt% nano-zirconia showed the highest transverse strength (P ≤ 0.05). Repairs with autopolymerized acrylic resin reinforced with 5 wt% zirconia showed the lowest transverse strength value. There was no significant difference between the groups repaired with repair resin without reinforcement, 2 wt% zirconia, and glass fiber reinforced resin. Conclusion. Reinforcing of repair material with nano-zirconia may significantly improve the transverse strength of some fractured denture base polymers. PMID:27366150

  10. Synthesis of improved phenolic resins

    NASA Technical Reports Server (NTRS)

    Delano, C. B.; Mcleod, A. H.

    1979-01-01

    Twenty seven addition cured phenolic resin compositions were prepared and tested for their ability to give char residues comparable to state-of-the-art phenolic resins. Cyanate, epoxy, allyl, acrylate, methacrylate and ethynyl derivatized phenolic oligomers were investigated. The novolac-cyanate and propargyl-novolac resins provided anaerobic char yields at 800 C of 58 percent. A 59 percent char yield was obtained from modified epoxy novolacs. A phosphonitrilic derivative was found to be effective as an additive for increasing char yields. The novolac-cyanate, epoxy-novolac and methacrylate-epoxy-novolac systems were investigated as composite matrices with Thornel 300 graphite fiber. All three resins showed good potential as composite matrices. The free radical cured methacrylate-epoxy-novolac graphite composite provided short beam shear strengths at room temperature of 93.3 MPa (13.5 ksi). The novolac-cyanate graphite composite produced a short beam shear strength of 74 MPa (10.7 ksi) and flexural strength of 1302 MPa (189 ksi) at 177 C. Air heat aging of the novolac-cyanate and epoxy novolac based composites for 12 weeks at 204 C showed good property retention.

  11. Clinical application of removable partial dentures using thermoplastic resin. Part II: Material properties and clinical features of non-metal clasp dentures.

    PubMed

    Fueki, Kenji; Ohkubo, Chikahiro; Yatabe, Masaru; Arakawa, Ichiro; Arita, Masahiro; Ino, Satoshi; Kanamori, Toshikazu; Kawai, Yasuhiko; Kawara, Misao; Komiyama, Osamu; Suzuki, Tetsuya; Nagata, Kazuhiro; Hosoki, Maki; Masumi, Shin-ichi; Yamauchi, Mutsuo; Aita, Hideki; Ono, Takahiro; Kondo, Hisatomo; Tamaki, Katsushi; Matsuka, Yoshizo; Tsukasaki, Hiroaki; Fujisawa, Masanori; Baba, Kazuyoshi; Koyano, Kiyoshi; Yatani, Hirofumi

    2014-04-01

    This position paper reviews physical and mechanical properties of thermoplastic resin used for non-metal clasp dentures, and describes feature of each thermoplastic resin in clinical application of non-metal clasp dentures and complications based on clinical experience of expert panels. Since products of thermoplastic resin have great variability in physical and mechanical properties, clinicians should utilize them with careful consideration of the specific properties of each product. In general, thermoplastic resin has lower color-stability and higher risk for fracture than polymethyl methacrylate. Additionally, the surface of thermoplastic resin becomes roughened more easily than polymethyl methacrylate. Studies related to material properties of thermoplastic resin, treatment efficacy and follow-up are insufficient to provide definitive conclusions at this time. Therefore, this position paper should be revised based on future studies and a clinical guideline should be provided. PMID:24746524

  12. Clinical application of removable partial dentures using thermoplastic resin. Part II: Material properties and clinical features of non-metal clasp dentures.

    PubMed

    Fueki, Kenji; Ohkubo, Chikahiro; Yatabe, Masaru; Arakawa, Ichiro; Arita, Masahiro; Ino, Satoshi; Kanamori, Toshikazu; Kawai, Yasuhiko; Kawara, Misao; Komiyama, Osamu; Suzuki, Tetsuya; Nagata, Kazuhiro; Hosoki, Maki; Masumi, Shin-ichi; Yamauchi, Mutsuo; Aita, Hideki; Ono, Takahiro; Kondo, Hisatomo; Tamaki, Katsushi; Matsuka, Yoshizo; Tsukasaki, Hiroaki; Fujisawa, Masanori; Baba, Kazuyoshi; Koyano, Kiyoshi; Yatani, Hirofumi

    2014-04-01

    This position paper reviews physical and mechanical properties of thermoplastic resin used for non-metal clasp dentures, and describes feature of each thermoplastic resin in clinical application of non-metal clasp dentures and complications based on clinical experience of expert panels. Since products of thermoplastic resin have great variability in physical and mechanical properties, clinicians should utilize them with careful consideration of the specific properties of each product. In general, thermoplastic resin has lower color-stability and higher risk for fracture than polymethyl methacrylate. Additionally, the surface of thermoplastic resin becomes roughened more easily than polymethyl methacrylate. Studies related to material properties of thermoplastic resin, treatment efficacy and follow-up are insufficient to provide definitive conclusions at this time. Therefore, this position paper should be revised based on future studies and a clinical guideline should be provided.

  13. Study of improved resins for advanced supersonic technology composites. Part 1: Heteroaromatic polymers containing ether groups. Part 2: Curing chemistry of aromatic polymers and composite studies

    NASA Technical Reports Server (NTRS)

    Takekoshi, T.; Hillig, W. B.; Mellinger, G. A.

    1975-01-01

    Fourteen ether-containing, aromatic dianhydrides have been synthesized from N-phenyl-3 or 4-nitrophthalimide and various bisphenols. The process involves nucleophilic displacement of activated nitro groups with bisphenolate ions. Ether-containing dianhydrides were indefinitely stable in the presence of atmospheric moisture. One-step, high temperature solution polymerization of the ether-containing dianhydrides with m-phenylene diamine, 4,4'-oxydianiline and 1, 3-bis(4-aminophenoxy)benzene afforded 42 polyetherimides. The polyetherimides were all soluble in m-cresol except two which were found to be crystalline. The glass transition temperatures of the polyetherimides ranged from 178 to 277 C. Soluble polybenzimidazopyrrolones containing ether groups were also prepared from the same ether-containing dianhydrides and aromatic tetraamines by one-step solution polymerization. Using low molecular weight polyetherimides, various thermoset resin systems were developed and tested as matrices for fiber-reinforced composites. The curing chemistry involving reaction of the phthalonitrile group and the o-diaminophenyl group was found to be generally applicable to crosslinking various aromatic polymers other than polyimides.

  14. Effect of accelerated aging on the microhardness and color stability of flexible resins for dentures.

    PubMed

    Goiato, Marcelo Coelho; Santos, Daniela Micheline dos; Haddad, Marcela Filie; Pesqueira, Aldiéris Alves

    2010-01-01

    Acrylic resins have been widely used due to their acceptable esthetics and desirable characteristics such as easy handling, good thermal conductivity, low permeability to oral fluids and color stability. Flexible resins were introduced on the market as an alternative to the use of conventional acrylic resins in the construction of complete and partial removable dentures. Although these resins present advantages in terms of esthetics and comfort, studies assessing chromatic and microhardness alterations of these materials are still scarce in the related literature. The aim of this study was to evaluate the chromatic and microhardness alterations of two commercial brands of flexible resins in comparison to the conventional resin Triplex when submitted to accelerated aging. The resins were manipulated according to manufacturers' instructions and inserted into a silicone matrix to obtain 21 specimens divided into 3 groups: Triplex, Ppflex and Valplast. Triplex presented the highest microhardness value (p < 0.05) for all the aging periods, which was significantly different from that of the other resins, followed by the values of Valplast and Ppflex. Comparison between the flexible resins (Ppflex and Valplast) revealed a statistically significant difference (p < 0.05) as regards color. The flexible resin Ppflex and the conventional resin Triplex presented no statistically significant difference (p < 0.05) as regards aging. The accelerated aging significantly increased the microhardness values of the resins, with the highest values being observed for Triplex. Valplast presented the greatest chromatic alteration after accelerated aging. PMID:20339724

  15. Bond strength of denture teeth to acrylic bases.

    PubMed

    Cunningham, J L

    1993-10-01

    The literature relating to the determination of the bond strength of plastic denture teeth to acrylic resin denture material is reviewed. The papers are presented in chronological order with information on specimen preparation, batch sizes and methods of testing. The lack of uniformity in experimental techniques and the diverse range of products assessed makes recommendations for laboratory practice difficult to formulate. One consistent observation is that tooth surface contamination with wax decreases the bond strength between the teeth and the denture base material. A universal testing method needs to be formulated to replace the various techniques now employed.

  16. Optical properties and indentation hardness of thin-film acrylated epoxidized oil

    NASA Astrophysics Data System (ADS)

    Rahman, Mohammad Syuhaimi Ab.; Shaktur, Khaled Mohamed; Mohammad, Rahmah; Zalikha, Wan Aimi; Nawi, Norwimie; Mohd, Ahmad Faiza

    2012-02-01

    Epoxy acrylate has been widely used as optical resin for applications such as cladding, the core of a waveguide, and other photonic devices. In this study, sustainable resin from edible oil was used as an alternative to epoxy acrylate. Structural features and the transmission of planar thin-film resin from an ultraviolet-visible spectroscopy (UV-VIS) spectrometer were investigated upon UV exposure. It was found that high transmission still persists for all samples with and without an UV absorber for exposed and unexposed samples. The film was found to absorb strongly below 400 nm. A change in the cut-off wavelength was observed upon exposure. Thin-film hardness and its dynamic indentation in the load-unload mode with different test forces were evaluated. Vickers hardness and the elastic modulus were determined for unacrylated epoxidized soybean oil (ESO) and acrylated epoxidized soybean oil (AESO). It was found that the AESO has a higher Vickers hardness and elastic modulus than those of unacrylated thin film. The Vickers hardness and elastic modulus were found to increase as the applied test force increased. The refractive index, thickness, and modes present were characterized from a spin-coated planar thin film. The refractive index in the transverse electric mode (TE) and transverse magnetic mode (TM) were determined and compared for unacrylated and acrylated epoxidized oil.

  17. Plastic casting resin poisoning

    MedlinePlus

    Epoxy poisoning; Resin poisoning ... Epoxy and resin can be poisonous if they are swallowed or their fumes are breathed in. ... Plastic casting resins are found in various plastic casting resin products.

  18. 21 CFR 173.5 - Acrylate-acrylamide resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (a) (1) of this section is used as a flocculent in the clarification of beet sugar juice and liquor... mineral scale in beet sugar juice and liquor or cane sugar juice and liquor in an amount not to exceed...

  19. 21 CFR 173.5 - Acrylate-acrylamide resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) of this section is used as a flocculent in the clarification of beet sugar juice and liquor or cane... scale in beet sugar juice and liquor or cane sugar juice and liquor in an amount not to exceed 2.5...

  20. Effect of light-curing, pressure, oxygen inhibition, and heat on shear bond strength between bis-acryl provisional restoration and bis-acryl repair materials

    PubMed Central

    Shim, Ji-Suk; Lee, Jeong-Yol; Choi, Yeon-Jo; Shin, Sang-Wan

    2015-01-01

    PURPOSE This study aimed to discover a way to increase the bond strength between bis-acryl resins, using a comparison of the shear bond strengths attained from bis-acryl resins treated with light curing, pressure, oxygen inhibition, and heat. MATERIALS AND METHODS Self-cured bis-acryl resin was used as both a base material and as a repair material. Seventy specimens were distributed into seven groups according to treatment methods: pressure - stored in a pressure cooker at 0.2 Mpa; oxygen inhibition- applied an oxygen inhibitor around the repaired material,; heat treatment - performed heat treatment in a dry oven at 60℃, 100℃, or 140℃. The shear bond strength was measured with a universal testing machine, and the shear bond strength (MPa) was calculated from the peak load of failure. A comparison of the bond strength between the repaired specimens was conducted using one-way ANOVA and Tukey multiple comparison tests (α=.05). RESULTS There were no statistically significant differences in the shear bond strength between the control group and the light curing, pressure, and oxygen inhibition groups. However, the heat treatment groups showed statistically higher bond strengths than the groups treated without heat, and the groups treated at a higher temperature resulted in higher bond strengths. Statistically significant differences were seen between groups after different degrees of heat treatment, except in groups heated at 100℃ and 140℃. CONCLUSION Strong bonding can be achieved between a bis-acryl base and bis-acryl repair material after heat treatment. PMID:25722837

  1. Composite resin in medicine and dentistry.

    PubMed

    Stein, Pamela S; Sullivan, Jennifer; Haubenreich, James E; Osborne, Paul B

    2005-01-01

    Composite resin has been used for nearly 50 years as a restorative material in dentistry. Use of this material has recently increased as a result of consumer demands for esthetic restorations, coupled with the public's concern with mercury-containing dental amalgam. Composite is now used in over 95% of all anterior teeth direct restorations and in 50% of all posterior teeth direct restorations. Carbon fiber reinforced composites have been developed for use as dental implants. In medicine, fiber-reinforced composites have been used in orthopedics as implants, osseous screws, and bearing surfaces. In addition, hydroxyapatite composite resin has become a promising alternative to acrylic cement in stabilizing fractures and cancellous screw fixation in elderly and osteoporotic patients. The use of composite resin in dentistry and medicine will be the focus of this review, with particular attention paid to its physical properties, chemical composition, clinical applications, and biocompatibility.

  2. Jetted mixtures of particle suspensions and resins

    NASA Astrophysics Data System (ADS)

    Hoath, S. D.; Hsiao, W.-K.; Hutchings, I. M.; Tuladhar, T. R.

    2014-10-01

    Drop-on-demand (DoD) ink-jetting of hard particle suspensions with volume fraction Φ ˜ 0.25 has been surveyed using 1000 ultra-high speed videos as a function of particle size (d90 = 0.8—3.6 μm), with added 2 wt. % acrylic (250 kDa) or 0.5 wt. % cellulose (370 kDa) resin, and also compared with Newtonian analogues. Jet break-off times from 80 μm diameter nozzles were insensitive (120 ± 10 μs) to particle size, and resin jet break-off times were not significantly altered by >30 wt. % added particles. Different particle size grades can be jetted equally well in practice, while resin content effectively controls DoD break-off times.

  3. Composite resins.

    PubMed

    Leinfelder, K F

    1985-04-01

    The interest in posterior composite resins has grown rapidly during the last several years. Much of the interest has been initiated by a demand for esthetic dentistry. Some has developed as a result of a concern by some for mercury sensitivity. Despite their growing popularity, a number of major problems persist. Some of these deal with the restorative material, whereas others relate to the clinical techniques associated with their use. Before the clinician considers the use of composite resins in posterior teeth, he or she should be familiar with conditions that strongly influence clinical behavior.

  4. Fractionation and utilization of gossypol resin

    SciTech Connect

    Tursunov, A.K.; Dzhailov, A.T.; Fatkhullaev, E.; Sadykov, A.A.

    1985-10-01

    Gossypol resin is formed as a secondary waste product during distillation of fatty acides isolated from cottonseed oil soap stocks; it is insoluble in water but soluble in products of petroleum distillation. For fractionation, gossypol resin was saponified with caustic soda or caustic potash. Using this method, the resin was separated into unsaponifiable (21-24%) and saponifiable (76-79%) parts. Details of the individual fractions of gossypol resin are presented. The unsaponifiable fraction contains hydrocarbons, alcohols, beta-sito-sterol, beta-amyrin, and vitamin E. The fatty acid fraction of the resin is a mixture of fatty acids and lactones.

  5. A Method for Characterizing PMR-15 Resin

    NASA Technical Reports Server (NTRS)

    Roberts, G. D.; Lauver, R. W.

    1986-01-01

    Quantitative analysis technique based on reverse-phase, highperformance liquid chromatography (HPLC) and paired-ion chromatography (PIC) developed for PMR-15 resins. In reverse-phase HPLC experiment, polar solvent containing material to be analyzed passed through column packed with nonpolar substrate. Composition of PMR-15 Resin of 50 weight percent changes as resin ages at room temperature. Verification of proper resin formulation and analysis of changes in resin composition during storage important to manufacturers of PMR-15 polymer matrix composite parts. Technique especially suitable for commercial use by manufacturers of high-performance composite components.

  6. Stress and flow analyses of ultraviolet-curable resin during curing

    NASA Astrophysics Data System (ADS)

    Umezaki, Eisaku; Okano, Akira; Koyama, Hiroto

    2014-06-01

    The stress and flow generated in ultraviolet (UV)-curable resin during curing in molds were measured to investigate their relationship. The specimens were molds consisting of glass plates and acrylic bars, and UV-curable liquid resin. The specimens were illuminated from above with UV rays. Photoelastic and visual images were separately obtained at a constant time interval using cameras during curing. To help obtain the visual images, acrylic powder was mixed with the liquid resin. The stress was obtained from the photoelastic images by a digital photoelastic technique with phase stepping, and the flow was obtained from the visual images by a particle-tracking velocimetry technique. Results indicate that the stress generated in the UV-curable resin during curing depends on the degree of contact between the mold and the cured area of the resin, and is hardly related to the flow.

  7. The stability of new transparent polymeric materials: The epoxy trimethoxyboroxine system. Part 1: The preparation, characterization and curing of epoxy resins and their copolymers

    NASA Technical Reports Server (NTRS)

    Pearce, E.; Lin, S. C.

    1981-01-01

    The effects of resin composition, curing conditions fillers, and flame retardant additives on the flammability of diglycidyl ether of bisphenol-A (DGEBA) as measured by the oxygen index is examined. The oxygen index of DGEBA cured with various curing agents was between 0.198 to 0.238. Fillers and flame retardant additives can increase the oxygen index dependent on the material and the amount used. Changes in the basic cured resin properties can be anticipated with the addition of noncompatible additives. High flame resistant epoxy resins with good stability and mechanical properties are investigated.

  8. Starch graft poly(methyl acrylate) loose-fill foam: preparation, properties and degradation.

    PubMed

    Chen, L; Gordon, S H; Imam, S H

    2004-01-01

    Starch graft poly(methyl acrylate) (S-g-PMA) was prepared by ceric ion initiation of methyl acrylate in an aqueous corn starch slurry (prime starch) which maximized the accessibility of the starch for graft polymerization. A new ceric ion reaction sequence was established as starch-initiator-methyl acrylate followed by addition of a small amount of ceric ion solution when the graft polymerization was almost complete to quench the reaction. As a result of this improved procedure, no unreacted methyl acrylate monomer remained, and thus, essentially no ungrafted poly(methyl acrylate) homopolymer was formed in the final grafted product. Quantities of the high purity S-g-PMA so prepared in pilot scale were converted to resin pellets and loose-fill foam by single screw and twin screw extrusion. The use of prime starch significantly improved the physical properties of the final loose-fill foam, in comparison to foam produced from regular dry corn starch. The S-g-PMA loose-fill foam had compressive strength and resiliency comparable to expanded polystyrene but higher bulk density. The S-g-PMA loose-fill foam also had better moisture and water resistance than other competitive starch-based materials. Studies indicated that the starch portion in S-g-PMA loose-fill foam biodegraded rapidly, whereas poly(methyl acrylate) remained relatively stable under natural environmental conditions.

  9. Resin composite repair: Quantitative microleakage evaluation of resin-resin and resin-tooth interfaces with different surface treatments

    PubMed Central

    Celik, Cigdem; Cehreli, Sevi Burcak; Arhun, Neslihan

    2015-01-01

    Objective: The aim was to evaluate the effect of different adhesive systems and surface treatments on the integrity of resin-resin and resin-tooth interfaces after partial removal of preexisting resin composites using quantitative image analysis for microleakage testing protocol. Materials and Methods: A total of 80 human molar teeth were restored with either of the resin composites (Filtek Z250/GrandioSO) occlusally. The teeth were thermocycled (1000×). Mesial and distal 1/3 parts of the restorations were removed out leaving only middle part. One side of the cavity was finished with course diamond bur and the other was air-abraded with 50 μm Al2O3. They were randomly divided into four groups (n = 10) to receive: Group 1: Adper Single Bond 2; Group 2: All Bond 3; Group 3: ClearfilSE; Group 4: BeautiBond, before being repaired with the same resin composite (Filtek Z250). The specimens were re-thermocycled (1000×), sealed with nail varnish, stained with 0.5% basic fuchsin, sectioned mesiodistally and photographed digitally. The extent of dye penetration was measured by image analysis software (ImageJ) for both bur-finished and air-abraded surfaces at resin-tooth and resin-resin interfaces. The data were analyzed statistically. Results: BeautiBond exhibited the most microleakage at every site. Irrespective of adhesive and initial composite type, air-abrasion showed less microleakage except for BeautiBond. The type of initial repaired restorative material did not affect the microleakage. BeautiBond adhesive may not be preferred in resin composite repair in terms of microleakage prevention. Conclusions: Surface treatment with air-abrasion produced the lowest microleakage scores, independent of the adhesive systems and the pre-existing resin composite type. Pre-existing composite type does not affect the microleakage issue. All-in-one adhesive resin (BeautiBond) may not be preferred in resin composite repair in terms of microleakage prevention. PMID:25713491

  10. Phenoxy resins containing pendent ethynyl groups

    NASA Technical Reports Server (NTRS)

    Hergenrother, P. M.; Jensen, B. J.; Havens, S. J.

    1984-01-01

    As part of an effort on tougher/solvent resistant matrix resins for composites, research was directed towards exploring methods to improve the solvent resistance of linear amorphous thermoplastics. Ethyl reactive groups were placed on the ends of oligomers and pendent along the polymer chain and subsequently thermally reacted to provide crosslinking and thus improvement in solvent resistance. This concept is extended to another thermoplastic, a phenoxy resin. A commercially available phenoxy resin (PKHH) was systematically modified by reaction of the pendent hydroxyl groups on the phenoxy resin with various amounts of 4-ethynylbenzoyl chloride. As the pendent ethynyl group content in the phenoxy resin increased, the cured resin exhibited a higher glass transition temperature, better solvent resistance and less flexibility. The solvent resistance was further improved by correcting a low molecular weight diethynyl compound, 2,2-bis(4-ethynylbenzoyloxy-4'-phenyl)propane, with a phenoxy resin containing pendent ethynyl groups.

  11. Synthesis and characterization of amphoteric resins and its use for treatment of radioactive liquid waste

    SciTech Connect

    Siyam, T.; El-Naggar, I.M.; Aly, H.F.

    1996-12-31

    Amphoteric resins such as poly (acrylamide-acrylic acid-diallylamine-hydrochloride) {open_quotes}P(AH-AA-DAA){sup +}Cl{close_quotes} and poly (acrylamide-acrylic acid-dially-ethylamine-hydrochloride) {open_quotes}P(AM-AA-DAEA){sup +} Cl{close_quotes} were prepared by gamma radiation-induced polymerization of acrylic acid {open_quotes}AA{close_quotes} in the presence of poly(amidoamines) such as poly(acryl-amide-diallyamine-hydrochloride) {open_quotes}P(AM- DAAH){sup +}Cl{close_quotes} and poly(acrylamide-dially-ethylamine-hydrochloride){close_quotes}P(AM-DAEAH){sup +} Cl{sup -}{close_quotes} it as template polymers using a template polymerization technique. Spectroscopic studies showed that resins contain both amide- and carboxylic groups, and the peak of {r_angle}NH of amine salts at (3000-2700 cm{sup {minus}1}) and (2700-2500 cm{sup {minus}1}) is disappeared. This indicates that the addition of acrylic acid monomer on ammonium groups. These ammonium groups in template polymers are converted into acrylic acid chain ends in the obtained resins accordingly, the probability of the polymer degradation of decreases may be attributed to the high radiation stability of these chain ends of acrylic acid units. The capacities of the obtained resins increase by increasing the absorbed doses of about {approximately}20 kGy, but at high doses the capacities decrease. On increasing the amines ratio in template polymers the capacities of resins for cation decreased but increased for anions. The capacities of the product materials to some heavy metal ions decrease with increasing the hydrogen ion concentrations and the selectivity is decreased in the order Cu{sup 2+} > Co{sup 2+} > Cs{sup +}.

  12. Effect of various chemicals on the bond strength of acrylic tooth and denture base -An Invitro comparative study

    PubMed Central

    Krishna, V Pridhvi; Premalatha, Averneni; Babu, P Jithendra; Raju, D Srinivasa; Kumar, M Praveen; Rao, D Bheemalingeswara

    2014-01-01

    Background: Debonding of acrylic teeth from the denture base is a common problem. Certain clinical conditions like ridge prominence leads to excess trimming of acrylic teeth and base, resulting in a weak interface. The denture base polymer debonds adhesively in the region of the highly cross –linked matrix of the teeth. To compare the effect of different chemical surface treatments on the bond between cross-linked acrylic teeth and different types of denture base material. Materials & Methods: A total of 180 wax specimens were fabricated and divided into 3 groups: Heat-cure, high impact heat-cure, flexible denture base material bonded to acrylic teeth. Each group was further subdivided into 6 subgroups with 10 specimens each according to the surface treatment ofthe ridge lap area: control, monomer, acetone 99%, chloroform 99%, acrylic adhesive cyanoacrylate, ethyl acetate 99%. After processing, specimens were tested for bond strength using a universal testing machine. The resulting bond strengths were recorded, statistically analyzed and compared. Results: Among all the 3types of denture base resins, highimpact heat-cure denture base resin gave highest bond strength. There was no bonding of teeth with flexible denture base material. Chemical surface treatment of acrylic teeth with ethyl acetate gave highest bond strength followed by control, chloroform, acetone and cyanoacrylate groups. Conclusion: Among all the 3types of denture base materials, high-impact heat-cure denture base resin gave highest bond strength with ethyl acetate surface treatment. Simple and quick tooth chemical surface treatment with ethylacetate could be an effective option in decreasing bonding failures and also avoid repeated denture repairs improving patient satisfaction. How to cite the article: Krishna VP, Premalatha A, Babu PJ, Raju DS, Kumar MP, Rao DB. Effect of various chemicals on the bond strength of acrylic tooth and denture base -An In-vitro comparative study. J Int Oral Health

  13. 40 CFR Table 7 to Subpart Wwww of... - Options Allowing Use of the Same Resin Across Different Operations That Use the Same Resin Type

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 12 2011-07-01 2009-07-01 true Options Allowing Use of the Same Resin Across Different Operations That Use the Same Resin Type 7 Table 7 to Subpart WWWW of Part 63 Protection... Part 63—Options Allowing Use of the Same Resin Across Different Operations That Use the Same Resin...

  14. 40 CFR 721.2805 - Acrylate ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Acrylate ester. 721.2805 Section 721... Acrylate ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an acrylate ester (PMN P-96-824) is subject to reporting under...

  15. 40 CFR 721.2805 - Acrylate ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Acrylate ester. 721.2805 Section 721... Acrylate ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an acrylate ester (PMN P-96-824) is subject to reporting under...

  16. 40 CFR 721.2805 - Acrylate ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Acrylate ester. 721.2805 Section 721... Acrylate ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an acrylate ester (PMN P-96-824) is subject to reporting under...

  17. 40 CFR 721.2805 - Acrylate ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Acrylate ester. 721.2805 Section 721... Acrylate ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an acrylate ester (PMN P-96-824) is subject to reporting under...

  18. Use of light-cured resin to manufacture occlusal splints: report of two cases.

    PubMed

    Więckiewicz, Mieszko; Miernik, Marta; Więckiewicz, Włodzimierz

    2012-01-01

    This article presents selected cases of patients with functional disorders of the stomatognathic system. This group of patients had a need to made different types of removable occlusal splints. In the past, occlusal appliances were made mostly using self-cured acrylate materials, which for many years had no replacements. The rapid development of dental materials technology led to creation of thermo-formable materials and resins, which can successfully replace traditional acrylic materials in daily clinical practice. A practical application of light-cured resin in the fabrication of the occlusal splints in two clinical cases is reported and discussed herein. PMID:23207866

  19. Mixing It Up with Acrylics.

    ERIC Educational Resources Information Center

    Laird, Shirley

    1999-01-01

    Presents an art activity for fifth-grade students in which they learn about basic shapes and what happens when shapes overlap, draw seven overlapping geometric shapes, review the use of acrylic paint and mixing colors, and finally paint with primary colors. (CMK)

  20. Flame Retardant Epoxy Resins

    NASA Technical Reports Server (NTRS)

    Thompson, C. M.; Smith, J. G., Jr.; Connell, J. W.; Hergenrother, P. M.; Lyon, R. E.

    2004-01-01

    As part of a program to develop fire resistant exterior composite structures for future subsonic commercial aircraft, flame retardant epoxy resins are under investigation. Epoxies and their curing agents (aromatic diamines) containing phosphorus were synthesized and used to prepare epoxy formulations. Phosphorus was incorporated within the backbone of the epoxy resin and not used as an additive. The resulting cured epoxies were characterized by thermogravimetric analysis, propane torch test, elemental analysis and microscale combustion calorimetry. Several formulations showed excellent flame retardation with phosphorous contents as low as 1.5% by weight. The fracture toughness of plaques of several cured formulations was determined on single-edge notched bend specimens. The chemistry and properties of these new epoxy formulations are discussed.

  1. Thermo-Optic Coefficient of Different Photosensitive Acrylate Polymers for Optical Application

    NASA Astrophysics Data System (ADS)

    Razali, N.; Mohamed, R.; Ehsan, A. A.; Kuang, C. S.; Shaari, S.

    Thermo-optic (TO) effect in materials can be exploited in the fabrication of optical devices such as optical switches and couplers. These optical devices play a key function in communication networks because by changing the temperature they have control over the optical path. Recently, polymer materials have begun to receive attention for the application of the TO switch in integrated optics. The polymers exploited for the variation of refractive index with temperature in our work involve the use of cyclomer acrylate, which is compared to the fluorinated acrylate available in the market. We focus the on cyclomer acrylate resin potential to be employed in fabricating optical devices especially the optical waveguide and optical switch. Formerly, this polymer is used as an adhesive and coating only. Different acrylate formulations from cyclomer acrylates have been exploited. Both acrylates show negative TO effects with temperature i.e. decrease of refractive index result in the increase in temperature. This is expected as the refractive index of the polymers are reduced, as density typically decreases with increasing temperature. This is in accordance to the dependence of polarizability and density of a particular material, to its refractive index. For both types of polymers, the change of the refractive index as a function of temperature is linear. The slope can give the dn/dT of the film. The dn/dT of polymers are as high as the order of 10-4, which is comparable to those of optical polymers. Higher values are shown by the cyclomer acrylate compared to the fluorinated type.

  2. Modification of surface properties of UV-cured films in the presence of long chain acrylic monomers

    SciTech Connect

    Bongiovanni, R.; Malucelli, G.; Priola, A.

    1995-05-01

    Acrylic films have been prepared by photopolymerization of mixtures of an epoxyacrylic resin with linear chain acrylic monomers having the structure H-(CH{sub 2}){sub n}-O-CO-CH {double_bond} CH{sub 2} with n ranging from 4 to 18. The resins were cast on a glass slide and cured in an inert atmosphere; their surface properties were investigated by advancing and receding contact angles and surface tension measurements according to the Zisman method. The pure resin film showed the same surface properties on both sides, that exposed to the atmosphere and that in contact with the substrate. Addition of the acrylic monomers caused an asymmetric distribution of them on the two sides of the film, depending on the alkylic chain length and on the acrylic monomer concentration. The asymmetry of the film was confirmed by XPS analysis that pointed out a significant enrichment of the apolar monomer on the air side. The surface properties were correlated to the monomer polarity (ruled by its hydrocarbon chain length). The contact angle hysteresis provided insight into the heterogeneity and the roughness of the polymeric surface.

  3. Subway mandibular buccal defect blocked with two part prosthesis unified by Earth magnets.

    PubMed

    Punjani, Shikha; Arora, Aman; Upadhyaya, Viram

    2013-03-01

    This clinical report describes the fabrication of a two-piece obturator used to close the mandibular buccal defect. Two-piece obturator prosthesis was fabricated with clear heat cure acrylic resin to be used during the healing period following the marsupialization of odontogenic keratocyst which had lead to the loss of portions of the mandibular buccal region. The prosthesis fabricated in two parts was joined by the rare earth magnets. Retention was increased by lining the prosthesis with tissue conditioner material engaging the undercut. PMID:24431709

  4. Subway mandibular buccal defect blocked with two part prosthesis unified by Earth magnets.

    PubMed

    Punjani, Shikha; Arora, Aman; Upadhyaya, Viram

    2013-03-01

    This clinical report describes the fabrication of a two-piece obturator used to close the mandibular buccal defect. Two-piece obturator prosthesis was fabricated with clear heat cure acrylic resin to be used during the healing period following the marsupialization of odontogenic keratocyst which had lead to the loss of portions of the mandibular buccal region. The prosthesis fabricated in two parts was joined by the rare earth magnets. Retention was increased by lining the prosthesis with tissue conditioner material engaging the undercut.

  5. Protonation and ion exchange equilibria of weak base anion-exchange resins.

    PubMed

    Miyazaki, Yoshinobu; Nakai, Mariko

    2011-09-30

    Protonation and ion exchange equilibria of weak base anion-exchange resins, in which tertiary amine moieties were introduced as a functional group, were investigated by applying NMR spectroscopy to species adsorbed into the resins. (31)P NMR signals of the phosphinate ion in the resin phases shifted to a lower field due to the influence of protonation of the tertiary amine groups of the resins in the pH range of 4-10. Protonation constants of the tertiary amine groups in styrene-divinylbenzene (DVB)-based resins were estimated to be K(H)=10(6.4) for Amberlite IRA96 and 10(6.5) for DIAION WA30 by the (31)P NMR method using the phosphinate ion as a probe species. In addition to the low field shift caused by the protonation of the tertiary amine moieties, another low field shift was observed for the phosphinate ion in acrylic acid-DVB-based resins at a rather high pH. This shift should be due to an unexpected deprotonation in the acrylic resin: a tautomerism accompanying the proton release from the amide form to the imide one in the functional group, thus, the resin could exhibit a cation exchange property at the high pH. Protonation constants of the tertiary amine moieties in the acrylic resins were estimated to be 10(8.8) for DIAION WA10, 10(9.0) for Amberlite IRA67 and 10(9.3) for Bio-Rad AG 4-X4 on the basis of the Henderson-Hasselbalch equation using the resin phase pH estimated by the (133)Cs and (1)H NMR signal intensities.

  6. Effect of resin thickness on the microhardness and optical properties of bulk-fill resin composites

    PubMed Central

    Kim, Eun-Ha; Jung, Kyoung-Hwa; Son, Sung-Ae; Hur, Bock; Kwon, Yong-Hoon

    2015-01-01

    Objectives This study evaluated the effects of the resin thickness on the microhardness and optical properties of bulk-fill resin composites. Methods Four bulk-fill (Venus Bulk Fill, Heraeus Kulzer; SDR, Dentsply Caulk; Tetric N-Ceram Bulk Fill, Ivoclar vivadent; SonicFill, Kerr) and two regular resin composites (Charisma flow, Heraeus Kulzer; Tetric N-Ceram, Ivoclar vivadent) were used. Sixty acrylic cylindrical molds were prepared for each thickness (2, 3 and 4 mm). The molds were divided into six groups for resin composites. The microhardness was measured on the top and bottom surfaces, and the colors were measured using Commission Internationale d'Eclairage (CIE) L*a*b* system. Color differences according to the thickness and translucency parameters and the correlations between the microhardness and translucency parameter were analyzed. The microhardness and color differences were analyzed by ANOVA and Scheffe's post hoc test, and a student t-test, respectively. The level of significance was set to α = 0.05. Results The microhardness decreased with increasing resin thickness. The bulk-fill resin composites showed a bottom/top hardness ratio of almost 80% or more in 4 mm thick specimens. The highest translucency parameter was observed in Venus Bulk Fill. All resin composites used in this study except for Venus Bulk Fill showed linear correlations between the microhardness and translucency parameter according to the thickness. Conclusions Within the limitations of this study, the bulk-fill resin composites used in this study can be placed and cured properly in the 4 mm bulk. PMID:25984474

  7. A method for preparing sodium acrylate-d3, a useful and stable precursor for deuterated acrylic monomers

    SciTech Connect

    Yang, Jun; Hong, Kunlun; Bonnesen, Peter V

    2011-01-01

    A convenient and economical method for converting propiolic acid to sodium acrylate-d3 is described. Successive D/H exchange of the alkyne proton of sodium propiolate (prepared from propiolic acid) using D2O affords sodium propiolate-d having up to 99 atom% D. Sodium propiolate-d can be partially reduced to sodium acrylate-d3 with 90% conversion and 89% yield, using D2 and the Lindlar catalyst with control of reaction parameters to maximize conversion while minimizing over reduction.

  8. SEM/EDX and vis spectrophotometry study of the stability of resin-bound mortars used for casting replicas and filling missing parts of historic stone fountains.

    PubMed

    Roig-Salom, José-Luis; Doménech-Carbó, María-Teresa; de la Cruz-Cañizares, Juana; Bolívar-Galiano, Fernando; Pelufo-Carbonell, María-José; Peraza-Zurita, Yaiza

    2003-04-01

    A study by SEM/EDX and spectrophotometry in the visible region attempting to assess the stability of new resin-bound mortars used for casting replicas of marble historic fountains is presented in this paper. Different accelerating tests such as thermal ageing, UV light ageing, ageing in an SO(2) pollutant chamber, freezing cycles ageing, salt crystallisation ageing, natural ageing and biological attack have been applied to a series of test specimens prepared with polyester-, epoxy- and gel-coat-bound mortars. Examination of morphology, measurement of chemical composition and chromatic coordinates before and after ageing treatments establish the higher stability and resistance properties of these resin-bound mortars by comparison to those from the natural marbles.

  9. SEM/EDX and vis spectrophotometry study of the stability of resin-bound mortars used for casting replicas and filling missing parts of historic stone fountains.

    PubMed

    Roig-Salom, José-Luis; Doménech-Carbó, María-Teresa; de la Cruz-Cañizares, Juana; Bolívar-Galiano, Fernando; Pelufo-Carbonell, María-José; Peraza-Zurita, Yaiza

    2003-04-01

    A study by SEM/EDX and spectrophotometry in the visible region attempting to assess the stability of new resin-bound mortars used for casting replicas of marble historic fountains is presented in this paper. Different accelerating tests such as thermal ageing, UV light ageing, ageing in an SO(2) pollutant chamber, freezing cycles ageing, salt crystallisation ageing, natural ageing and biological attack have been applied to a series of test specimens prepared with polyester-, epoxy- and gel-coat-bound mortars. Examination of morphology, measurement of chemical composition and chromatic coordinates before and after ageing treatments establish the higher stability and resistance properties of these resin-bound mortars by comparison to those from the natural marbles. PMID:12733035

  10. Effect of tyrosol on adhesion of Candida albicans and Candida glabrata to acrylic surfaces.

    PubMed

    Monteiro, Douglas Roberto; Feresin, Leonardo Perina; Arias, Laís Salomão; Barão, Valentim Adelino Ricardo; Barbosa, Debora Barros; Delbem, Alberto Carlos Botazzo

    2015-09-01

    The prevention of adhesion of Candida cells to acrylic surfaces can be regarded as an alternative to prevent denture stomatitis. The use of quorum sensing molecules, such as tyrosol, could potentially interfere with the adhesion process. Therefore, the aim of this study was to assess the effect of tyrosol on adhesion of single and mixed cultures of Candida albicans and Candida glabrata to acrylic resin surfaces. Tyrosol was diluted in each yeast inoculum (10(7) cells/ml in artificial saliva) at 25, 50, 100, and 200 mM. Then, each dilution was added to wells of 24-well plates containing the acrylic specimens, and the plates were incubated at 37°C for 2 h. After, the effect of tyrosol was determined by total biomass quantification, metabolic activity of the cells and colony-forming unit counting. Chlorhexidine gluconate (CHG) was used as a positive control. Data were analyzed using analysis of variance (ANOVA) and the Holm-Sidak post hoc test (α = 0.05). The results of total biomass quantification and metabolic activity revealed that the tyrosol promoted significant reductions (ranging from 22.32 to 86.16%) on single C. albicans and mixed cultures. Moreover, tyrosol at 200 mM and CHG significantly reduced (p < 0.05) the number of adhered cells to the acrylic surface for single and mixed cultures of both species, with reductions ranging from 1.74 to 3.64-log10. In conclusion, tyrosol has an inhibitory effect on Candida adhesion to acrylic resin, and further investigations are warranted to clarify its potential against Candida infections. PMID:26162470

  11. Effect of tyrosol on adhesion of Candida albicans and Candida glabrata to acrylic surfaces.

    PubMed

    Monteiro, Douglas Roberto; Feresin, Leonardo Perina; Arias, Laís Salomão; Barão, Valentim Adelino Ricardo; Barbosa, Debora Barros; Delbem, Alberto Carlos Botazzo

    2015-09-01

    The prevention of adhesion of Candida cells to acrylic surfaces can be regarded as an alternative to prevent denture stomatitis. The use of quorum sensing molecules, such as tyrosol, could potentially interfere with the adhesion process. Therefore, the aim of this study was to assess the effect of tyrosol on adhesion of single and mixed cultures of Candida albicans and Candida glabrata to acrylic resin surfaces. Tyrosol was diluted in each yeast inoculum (10(7) cells/ml in artificial saliva) at 25, 50, 100, and 200 mM. Then, each dilution was added to wells of 24-well plates containing the acrylic specimens, and the plates were incubated at 37°C for 2 h. After, the effect of tyrosol was determined by total biomass quantification, metabolic activity of the cells and colony-forming unit counting. Chlorhexidine gluconate (CHG) was used as a positive control. Data were analyzed using analysis of variance (ANOVA) and the Holm-Sidak post hoc test (α = 0.05). The results of total biomass quantification and metabolic activity revealed that the tyrosol promoted significant reductions (ranging from 22.32 to 86.16%) on single C. albicans and mixed cultures. Moreover, tyrosol at 200 mM and CHG significantly reduced (p < 0.05) the number of adhered cells to the acrylic surface for single and mixed cultures of both species, with reductions ranging from 1.74 to 3.64-log10. In conclusion, tyrosol has an inhibitory effect on Candida adhesion to acrylic resin, and further investigations are warranted to clarify its potential against Candida infections.

  12. Esterification of acrylic acid with methanol

    SciTech Connect

    Chubarov, G.A.; Danov, S.M.; Logutov, V.I.; Obmelyukhina, T.N.

    1984-01-01

    The esterification of acrylic acid with methanol in the absence of catalysis by strong mineral acids has been studied. The esterification rate was estimated from the amount of methyl acrylate formed at the end of a definite time, and the reaction rate was found to be first order with respect to methanol and second order with respect to acrylic acid. Mathematical relationships in good agreement with experimental data were derived from the results of the kinetic studies.

  13. The effect of polishing systems on microleakage of tooth coloured restoratives: Part 1. Conventional and resin-modified glass-ionomer cements.

    PubMed

    Yap, A U; Tan, S; Teh, T Y

    2000-02-01

    The purpose of this in vitro study was to investigate the effect of polishing systems on the microleakage of conventional and resin-modified glass-ionomer cements. Class V cavities were prepared at the cemento-enamel junction of 80 freshly extracted posterior teeth. The prepared teeth were randomly divided into two groups and restored with conventional or resin-modified glass-ionomer cements. The restored teeth were stored in distilled water at 37 degrees C for 1 week after removal of excess restorative with diamond finishing burs. The restored teeth were then divided into four groups of 10 and finished and polished using the following systems: Two Striper MFS; Sof-Lex XT; Enhance Composite Finishing and Polishing System; Shofu Composite Finishing Kit. The finished restorations were subjected to dye penetration testing. Results showed that the microleakage at dentin margins of conventional glass-ionomer cements and enamel margins of resin-modified glass-ionomer cements are significantly affected by the different polishing systems.

  14. Spectral filters based on ethylene/acrylic acid copolymer ionomers

    SciTech Connect

    Riley, M.O.; Walkup, C.M.; Hagen, W.F.; Jessop, E.S.

    1988-09-01

    We are investigating the possibility of utilizing ionomers as inexpensive, easily replaced optical filters for applications in large fusion lasers as well as high average power solid state lasers. To this end we have synthesized a number of other derivatives of the ethylene/acrylic acid (EAA) copolymer system. Specifically, we prepared several ionomers at nominal 3 wt. % metal ion concentration, including Fe(III), Co(II), Ni(II), Cu(II), and Ce(III), by reacting aqueous solutions of metal acetates or nitrates with aqueous ammonia dispersions (1) of EAA as described previously. The products were compression molded into thin optically clear films under the above-described conditions. A gel was formed in a similar reaction with samarium (III) nitrate. Accordingly, the samarium ionomer was synthesized by a melt phase reaction between the EAA resin and the metal nitrate. 6 refs., 2 figs., 2 tabs.

  15. FT-IR and FT-Raman studies of cross-linking processes with Ca(2+) ions, glutaraldehyde and microwave radiation for polymer composition of poly(acrylic acid)/sodium salt of carboxymethyl starch--part I.

    PubMed

    Grabowska, Beata; Sitarz, Maciej; Olejnik, Ewa; Kaczmarska, Karolina

    2015-01-25

    FT-IR and FT-Raman spectroscopic methods allowed to identify the cross-linking process of the aqueous composition of poly(acrylic acid)/sodium salt of carboxymethyl starch (PAA/CMS-Na) applied as a binder for moulding sands. The cross-linking was performed by chemical methods by introducing cross-linking substances with Ca(2+) ions or glutaraldehyde and by physical way, applying the microwave radiation. It was found that Ca(2+) ions cause formation of cross-linking ionic bonds within carboxyl and carboxylate groups. Glutaraldehyde generates formation of cross-linking bonds with hemiacetal and acetal structures. Whereas in the microwave radiation field, due to dehydration, lattices are formed by anhydride bonds.

  16. FT-IR and FT-Raman studies of cross-linking processes with Ca2+ ions, glutaraldehyde and microwave radiation for polymer composition of poly(acrylic acid)/sodium salt of carboxymethyl starch - Part I

    NASA Astrophysics Data System (ADS)

    Grabowska, Beata; Sitarz, Maciej; Olejnik, Ewa; Kaczmarska, Karolina

    2015-01-01

    FT-IR and FT-Raman spectroscopic methods allowed to identify the cross-linking process of the aqueous composition of poly(acrylic acid)/sodium salt of carboxymethyl starch (PAA/CMS-Na) applied as a binder for moulding sands. The cross-linking was performed by chemical methods by introducing cross-linking substances with Ca2+ ions or glutaraldehyde and by physical way, applying the microwave radiation. It was found that Ca2+ ions cause formation of cross-linking ionic bonds within carboxyl and carboxylate groups. Glutaraldehyde generates formation of cross-linking bonds with hemiacetal and acetal structures. Whereas in the microwave radiation field, due to dehydration, lattices are formed by anhydride bonds.

  17. Hand/face/neck localized pattern: sticky problems--resins.

    PubMed

    Cao, Lauren Y; Sood, Apra; Taylor, James S

    2009-07-01

    Plastic resin systems have an increasingly diverse array of applications but also induce health hazards, the most common of which are allergic and irritant contact dermatitis. Contact urticaria, pigmentary changes, and photoallergic contact dermatitis may occasionally occur. Other health effects, especially respiratory and neurologic signs and symptoms, have also been reported. These resin systems include epoxies, the most frequent synthetic resin systems to cause contact dermatitis, (meth)acrylics, polyurethanes, phenol-formaldehydes, polyesters, amino resins (melamine-formaldehydes, urea-formaldehydes), polyvinyls, polystyrenes, polyolefins, polyamides and polycarbonates. Contact dermatitis usually occurs as a result of exposure to the monomers and additives in the occupational setting, although reports from consumers, using the raw materials or end products periodically surface. Resin- and additive-induced direct contact dermatitis usually presents on the hands, fingers, and forearms, while facial, eyelid, and neck involvement may occur through indirect contact, eg, via the hands, or from airborne exposure. Patch testing with commercially available materials, and in some cases the patient's own resins, is important for diagnosis. Industrial hygiene prevention techniques are essential to reduce contact dermatitis when handling these resin systems.

  18. Salivary contamination and post-cured resin/resin lute bond.

    PubMed

    Stokes, A N; Pereira, B P

    1994-01-01

    A previous study has shown that sandblasting and silane priming a post-cured inlay resin gave a secure bond to dual-cure luting resin. To determine the influence of salivary contamination 4 additional groups of 15 post-cured resin discs were mounted in acrylic cylinders, their faces sandblasted with 50 microns alumina and silane primed. Surface treatments with saliva (sa), air/water spray (a/w), phosphoric acid gel (pa), and silane (si) followed in the order listed: A) control, no further treatment; B) sa, a/w; C) sa, a/w, si; D) sa, a/w, pa a/w; E) sa, a/w, pa, a/w, si. A 3.9 mm diameter column of dual-cure resin lute was then bonded to the dry stored in water surfaces. Specimens were stored in water for 2 weeks after which the dual-cure resin columns were sheared off the post-cured resin discs. Shear bond strengths were A) 19.2 +/- 3.7, B) 17.4 +/- 3.9, C) 16.7 +/- 3.1, D) 15.6 +/- 3.5, E) 15.4 +/- 2.3 MPa. One-way ANOVA and Duncan's Multiple Range Procedure showed groups D and E to be significantly lower than the uncontaminated control group A (p < 0.05). There were 2 adhesive failures in group B and all others were cohesive within the post-cured resin discs. This implies that air/water alone after salivary contamination is an unreliable cleansing method. The low shear bond values for Groups D and E may have been related to inadequate clearance of the phosphoric acid gel. It was concluded that salivary contamination adversely affected the quality of the bonds studied and decontamination using phosphoric acid gel resulted in significantly reduced shear bond strengths.

  19. 21 CFR 177.1380 - Fluorocarbon resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 1 CFR part 51. Copies may be obtained from the American Society for Testing and Materials, 1916 Race... of the resin pellets, when extracted with 100 milliliters of 50 percent (by volume) ethyl alcohol...

  20. 21 CFR 177.1380 - Fluorocarbon resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 1 CFR part 51. Copies may be obtained from the American Society for Testing and Materials, 1916 Race... of the resin pellets, when extracted with 100 milliliters of 50 percent (by volume) ethyl alcohol...

  1. 21 CFR 177.1380 - Fluorocarbon resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 1 CFR part 51. Copies may be obtained from the American Society for Testing and Materials, 1916 Race... of the resin pellets, when extracted with 100 milliliters of 50 percent (by volume) ethyl alcohol...

  2. 21 CFR 177.1380 - Fluorocarbon resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 1 CFR part 51. Copies may be obtained from the American Society for Testing and Materials, 1916 Race... of the resin pellets, when extracted with 100 milliliters of 50 percent (by volume) ethyl alcohol...

  3. Additive effects on the toughening of unsaturated polyester resins

    SciTech Connect

    Suspene, L.; Yang, Y.S.; Pascault, J.P.

    1993-12-31

    An elastomer additive, carboxy-terminated acrylonitrile-butadiene copolymer, was used for toughening in the free radical cross-linking copolymerization of unsaturated polyester (UP) resins. For molded parts, Charpy impact behavior was generally enhanced and the number of catastrophic failures was reduced. The miscibility and interfacial properties of additive and resin blends play important roles in the toughening process. Phase-diagram studies showed that the elastomer additive is immiscible with the UP resin and is phase-separated from the resin matrix during curing. This phase-separation phenomenon is similar to that in the low-profile mechanism of UP resins. Additive-resin system miscibility greatly influences curing morphology. Microvoids occurred in the additive phase of cured resin because of shrinkage stress. The intrinsic inhomogeneity of the polyester network and the existence of microvoids in the final product limit the toughening effect of additives on unsaturated polyester resins. 49 refs., 13 figs., 3 tabs.

  4. Through-hole optimization using plasma desmearing system. [Removal of resin

    SciTech Connect

    Gentry, F.L.

    1986-12-01

    To assure a reliable multilayer printed wiring product, all traces of resin smear must be removed from interconnect holes prior to electroplating. Plasma processing will remove this resin smear from the new laminates being introduced to our industry as well as the standard epoxy materials. Plasma desmearing also has the potential of eliminating many of the negative aspects associated with ''wet'' chemical processing. This report describes the full characterization of a production plasma etchback/desmear system (PEDS), as used in a prototype fabrication environment. Processing parameters were established for epoxy, polyimide, and acrylic resin systems.

  5. Two-Dimensional Patterning of Inorganic Particles in Resin Using Ultrasound-Induced Plate Vibration

    NASA Astrophysics Data System (ADS)

    Tuziuti, Toru; Masuda, Yoshitake; Yasui, Kyuichi; Kato, Kazumi

    2011-08-01

    The fabrication of a two-dimensional millimeter-sized pattern of micrometer-sized titanium dioxide particles in UV-reactive acrylic resin using 1.93 MHz ultrasound is demonstrated. A mixture of particles and resin is set in a thin layer between square glass plates of which one plate is irradiated with ultrasound. Both vibration normal to the plate and the wave propagating in the mixture form standing waves to provide a two-dimensional pattern of the particles. Scanning electron microscopy and X-ray diffraction analysis of the UV-hardened pattern indicate that the titanium dioxide particles are embedded in the resin.

  6. Custom cranioplasty using stereolithography and acrylic.

    PubMed

    D'Urso, P S; Earwaker, W J; Barker, T M; Redmond, M J; Thompson, R G; Effeney, D J; Tomlinson, F H

    2000-04-01

    Numerous methods of cranioplasty have been described. Customization and prefabrication have been reported to reduce operating time and improve cosmesis. An original technique for the manufacture of customized cranioplastic implants has been developed and tested in 30 patients.Thirty patients requiring cranioplasties were selected. Data acquired from computed tomography (CT) were used to manufacture exact plastic replicas (biomodels) of craniotomy defects and master cranioplastic implants using the rapid prototyping technology of stereolithography (SL). The three-dimensional (3D) imaging techniques of mirroring and interpolation were used to extrapolate on existing anatomy to design the master implants. The master implants were hand finished to fit the defect in the corresponding cranial biomodel exactly and were then used to create a cavity mould. The mould was used to cast thermally polymerised custom acrylic implants. The surgeons reported that the customized implants reduced operating time, afforded excellent cosmesis and were cost effective. The patients reported that the opportunity to see the biomodel and implant preoperatively improved their understanding of the procedure. Two complications were noted, one infection and one implant required significant trimming. The simultaneous manufacture of the master implant (male) and biomodel (female) components from SL allowed custom accurate implants to be manufactured. Disadvantages identified were the time required for computer manipulations of the CT data (up to 2 h), difficulty in assessing the accuracy of the computer generated master as a 3D rendering, the potential for SL parts to warp, manufacturing time (minimum 2 days) and the cost of approximately $1300 US per case ($1000 for the SL biomodel and $300 for the acrylic casting). PMID:10738323

  7. 40 CFR 721.2805 - Acrylate ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Acrylate ester. 721.2805 Section 721... Acrylate ester. Link to an amendment published at 79 FR 34637, June 18, 2014. (a) Chemical substance and... ester (PMN P-96-824) is subject to reporting under this section for the significant new uses...

  8. Bond strengths of composite resin and compomers in primary and permanent teeth.

    PubMed

    Jumlongras, D; White, G E

    1997-01-01

    Previous clinical and in vitro studies have shown a higher failure rate of composite resins and conventional glass ionomer cements in primary teeth when compared to permanent teeth. A new generation of light-cured glass ionomer cements (compomers) were suggested to be used as restorative materials for the primary teeth. This study was conducted into two parts. The objective of the first part was to compare shear bond strength of compomers (Compoglass and Dyract) and composite resin (Herculite/Optibond) in both primary and permanent teeth. Buccal and lingual surfaces of extracted sound human primary and permanent molars were ground flat on 600-grit SiC paper and divided into 6 groups of 10 surfaces each. The materials were handled according to the instructions of the manufacturer and placed on to the tooth surfaces via clear plastic tubes of 3 mm in diameter. After light curing for 40 seconds, all samples were thermocycled in water bath of 5 degrees F and 55 degrees F for 500 cycles. The samples were embedded in acrylic resin and sheared with an Instron running at a crosshead speed of 0.5 mm/min. Results (mean shear bond strength) were recorded in MPa. Factorial ANOVA revealed that shear bond strength of Herculite/Optibond in the primary teeth (6.07 +/- 2.63) was significantly lower than that of the permanent teeth (17.61 +/- 4.34) (p < 0.0001), but there was no statistically significant difference of bond strength of Compoglass and Dyract between the primary and the permanent teeth. The results from the first part revealed that no materials tested in the primary teeth could provide a shear bond strength of at least 17.6 MPa as recommended. Thus, the objective of the second part of this study was to evaluate shear bond strength of composite resin (Herculite) using three different dentinal bonding agents (Optibond, One-Step and Amalgambond) in the primary teeth. Methods employed in this part were similar to that of the first part. Results showed that Amalgambond

  9. Resin transfer molding speeds composite making

    NASA Astrophysics Data System (ADS)

    Valenti, Michael

    1992-11-01

    Fabrication resin transfer molding (RTM) composite parts for different industrial applications is discussed. These applications include composite aerospace parts, sports car components, and high performance sporting equipment. It is pointed out that RTM parts are lighter than metals and can be formulated to have superior durability. But like all composite parts, they are expensive and are made in limited runs.

  10. MM and QM: Conformational and vibrational spectra analysis of 2-hydroxyethyl acrylate

    NASA Astrophysics Data System (ADS)

    Belaidi, O.; Adjim, M.; Bouchaour, T.; Maschke, U.

    2015-02-01

    2-Hydroxyethyl acrylate is generally used with other acrylic and methacrylic products in order to get the desired characteristics of the final product. In this work we are about to make an assignment of experimental infrared bands with the help of a theoretical quantum chemistry calculations. The exact knowledge of some bands which are not characteristics of acrylic materials will enable us to make a quick analysis with available techniques of low costs for mixtures of polymers based on acrylate and methacrylate molecules. In the experimental part, the infrared spectrum of 2-hydroxyethyl acrylate is obtained by using a FTIR Perkin Elmer model 2000. In the computational part and as first step, the theoretical calculations are performed by the semi-empirical AM1 method for excluding similar structures of 2-hydroxyethyl acrylate molecule by a meticulous conformational analysis. As a second step the obtained structures are optimized using DFT. The simulated frequencies are then scaled and a tentative assignment is made based on band intensities and PED percentages. The theoretical calculations predict the existence of thirteen conformations two of them represent the majority of experimental bands in the infrared spectrum. Two neighbor experimental bands located at 1301 and 1207 cm-1 maybe used as characteristic bands to locate and distinguish the existence of one or both conformations.

  11. Effect of SiO2-acryl nanohybrid coating layers on transparent conducting oxide-poly(ethylene terephthalate) superstrate.

    PubMed

    Kang, Y T; Kang, D P; Kang, D J; Chung, I D

    2013-05-01

    SiO2-acryl nanohybrid coating layers were produced by hybridizing acrylic resin and surface-modified colloidal silica (CS) nanoparticles. First, CS nanoparticles were modified with methyltrimethoxysilane (MTMS) and vinyltrimethoxysilane (VTMS) by a sol-gel process. The surface-modified CS nanoparticles were then solvent-exchanged to be homogeneous in acrylic resin. The Hybrid materials were mixed in variation with the amount of surface-modified CS nanoparticles, coated with poly(ethylene terephthalate) (PET), then finally cured by UV light to obtain a hybrid coating layer. Field emission scanning electron microscopy (FE-SEM), particle size analysis (using a Zetasizer), and atomic force microscopy (AFM) were performed to determine the morphology of the hybrid thin-films. Thermogravimetric analysis (TGA) was used to investigate the thermal properties. Fourier-transform infrared (FTIR), ultraviolet-visible (UVNis) spectroscopies, and pencil hardness were used to obtain the details of chemical structures, optical properties, and hardness, respectively. The hybrid thin films had shown to be enhanced properties compared to their urethane acrylate prepolymer (UAP) coating film. PMID:23858925

  12. Effect of SiO2-acryl nanohybrid coating layers on transparent conducting oxide-poly(ethylene terephthalate) superstrate.

    PubMed

    Kang, Y T; Kang, D P; Kang, D J; Chung, I D

    2013-05-01

    SiO2-acryl nanohybrid coating layers were produced by hybridizing acrylic resin and surface-modified colloidal silica (CS) nanoparticles. First, CS nanoparticles were modified with methyltrimethoxysilane (MTMS) and vinyltrimethoxysilane (VTMS) by a sol-gel process. The surface-modified CS nanoparticles were then solvent-exchanged to be homogeneous in acrylic resin. The Hybrid materials were mixed in variation with the amount of surface-modified CS nanoparticles, coated with poly(ethylene terephthalate) (PET), then finally cured by UV light to obtain a hybrid coating layer. Field emission scanning electron microscopy (FE-SEM), particle size analysis (using a Zetasizer), and atomic force microscopy (AFM) were performed to determine the morphology of the hybrid thin-films. Thermogravimetric analysis (TGA) was used to investigate the thermal properties. Fourier-transform infrared (FTIR), ultraviolet-visible (UVNis) spectroscopies, and pencil hardness were used to obtain the details of chemical structures, optical properties, and hardness, respectively. The hybrid thin films had shown to be enhanced properties compared to their urethane acrylate prepolymer (UAP) coating film.

  13. Synthesis of iodine-containing cyclophosphazenes for using as radiopacifiers in dental composite resin.

    PubMed

    Zhao, Yuchen; Lan, Jinle; Wang, Xiaoyan; Deng, Xuliang; Cai, Qing; Yang, Xiaoping

    2014-10-01

    In this study, a strategy of using iodine-containing cyclophosphazenes as radiopacifiers for dental composite resin was evaluated. It was hypothesized that cyclophosphazenes bearing both iodine and acrylate group swere able to endow composite resins radiopacity without compromising mechanical properties. The cyclophosphazene compounds were synthesized by subsequently nucleophilic substitution of hexachlorocyclotriphosphazene with hydroxyethyl methacrylate (HEMA) and 4-iodoaniline. Cyclotriphosphazenes containing two different molar ratios of HEMA to 4-iodoaniline (1:5 and 2:4) were obtained, and were identified with (1)H NMR, FT-IR, UV and mass spectroscopy. The iodine-containing cyclophosphazenes were able to dissolve well in bisphenol A glycidyl methacrylate (Bis-GMA)/triethylene glycol dimethacrylate (TEGDMA) resin, and were added at two contents (10 or 15%wt. of the resin). The resins were photo-cured and post-thermal treated before characterizations. The resulting composite resins demonstrated the ability of blocking X-ray. And the addition of HEMA-co-iodoaniline substituted cyclotriphosphazenes caused minor adverse effect on the mechanical properties of the resins because the cyclotriphosphazenes could mix well and react with the resins. The presence of rigid phosphazene rings between resin backbones displayed an effective function of decreasing polymerization shrinkage. In summary, soluble and reactive iodine-containing cyclotriphosphazenes demonstrated advantages over traditional heavy metals or metal oxides in being used as additives for producing radiopaque dental resins.

  14. Synthesis and characterization of core-shell acrylate based latex and study of its reactive blends.

    PubMed

    Liu, Xiang; Fan, Xiao-Dong; Tang, Min-Feng; Nie, Ying

    2008-03-01

    Techniques in resin blending are simple and efficient method for improving the properties of polymers, and have been used widely in polymer modification field. However, polymer latex blends such as the combination of latexes, especially the latexes with water-soluble polymers, were rarely reported. Here, we report a core-shell composite latex synthesized using methyl methacrylate (MMA), butyl acrylate (BA), 2-ethylhexyl acrylate (EHA) and glycidyl methacrylate (GMA) as monomers and ammonium persulfate and sodium bisulfite redox system as the initiator. Two stages seeded semi-continuous emulsion polymerization were employed for constructing a core-shell structure with P(MMA-co-BA) component as the core and P(EHA-co-GMA) component as the shell. Results of Transmission Electron Microscopy (TEM) and Dynamics Light Scattering (DLS) tests confirmed that the particles obtained are indeed possessing a desired core-shell structural character. Stable reactive latex blends were prepared by adding the latex with waterborne melamine-formaldehyde resin (MF) or urea-formaldehyde resin (UF). It was found that the glass transition temperature, the mechanical strength and the hygroscopic property of films cast from the latex blends present marked enhancements under higher thermal treatment temperature. It was revealed that the physical properties of chemically reactive latexes with core-shell structure could be altered via the change of crosslinking density both from the addition of crosslinkers and the thermal treatment.

  15. Synthesis and Characterization of Core-Shell Acrylate Based Latex and Study of Its Reactive Blends

    PubMed Central

    Liu, Xiang; Fan, Xiao-Dong; Tang, Min-Feng; Nie, Ying

    2008-01-01

    Techniques in resin blending are simple and efficient method for improving the properties of polymers, and have been used widely in polymer modification field. However, polymer latex blends such as the combination of latexes, especially the latexes with water-soluble polymers, were rarely reported. Here, we report a core-shell composite latex synthesized using methyl methacrylate (MMA), butyl acrylate (BA), 2-ethylhexyl acrylate (EHA) and glycidyl methacrylate (GMA) as monomers and ammonium persulfate and sodium bisulfite redox system as the initiator. Two stages seeded semi-continuous emulsion polymerization were employed for constructing a core-shell structure with P(MMA-co-BA) component as the core and P(EHA-co-GMA) component as the shell. Results of Transmission Electron Microscopy (TEM) and Dynamics Light Scattering (DLS) tests confirmed that the particles obtained are indeed possessing a desired core-shell structural character. Stable reactive latex blends were prepared by adding the latex with waterborne melamine-formaldehyde resin (MF) or urea-formaldehyde resin (UF). It was found that the glass transition temperature, the mechanical strength and the hygroscopic property of films cast from the latex blends present marked enhancements under higher thermal treatment temperature. It was revealed that the physical properties of chemically reactive latexes with core-shell structure could be altered via the change of crosslinking density both from the addition of crosslinkers and the thermal treatment. PMID:19325753

  16. [Preparation of carbon fiber reinforced fluid type resin denture (author's transl)].

    PubMed

    Kasuga, H; Sato, H; Nakabayashi, N

    1980-01-01

    Transverse strength of cured fluid resins is weaker than that of the heat cured. We have studied to improve the mechanical strength of self-cured acrylic resin by application of carbon fibers as reinforcement and simple methods which must be acceptable for technicians are proposed. A cloth type carbon fiber was the best reinforcement among studied carbon fibers such as chopped or mat. The chopped fibers were difficult to mix homogeneously with fluid resins and effectiveness of the reinforcement was low. Breaking often occurred at the interface between the reinforcement and resin in the cases of mat which gave defects to the test specimens. To prepare reinforced denture, the cloth was trimmed on the master cast after removal of wax and the prepreg was formed with the alginate impression on the cast by Palapress and the cloth. Other steps were same as the usual fluid resin. PMID:6929856

  17. [Preparation of carbon fiber reinforced fluid type resin denture (author's transl)].

    PubMed

    Kasuga, H; Sato, H; Nakabayashi, N

    1980-01-01

    Transverse strength of cured fluid resins is weaker than that of the heat cured. We have studied to improve the mechanical strength of self-cured acrylic resin by application of carbon fibers as reinforcement and simple methods which must be acceptable for technicians are proposed. A cloth type carbon fiber was the best reinforcement among studied carbon fibers such as chopped or mat. The chopped fibers were difficult to mix homogeneously with fluid resins and effectiveness of the reinforcement was low. Breaking often occurred at the interface between the reinforcement and resin in the cases of mat which gave defects to the test specimens. To prepare reinforced denture, the cloth was trimmed on the master cast after removal of wax and the prepreg was formed with the alginate impression on the cast by Palapress and the cloth. Other steps were same as the usual fluid resin.

  18. Radiopurity measurement of acrylic for DEAP-3600

    SciTech Connect

    Nantais, C. M.; Boulay, M. G.; Cleveland, B. T.

    2013-08-08

    The spherical acrylic vessel that contains the liquid argon target is the most critical detector component in the DEAP-3600 dark matter experiment. Alpha decays near the inner surface of the acrylic vessel are one of the main sources of background in the detector. A fraction of the alpha energy, or the recoiling nucleus from the alpha decay, could misreconstruct in the fiducial volume and result in a false candidate dark matter event. Acrylic has low levels of inherent contamination from {sup 238}U and {sup 232}Th. Another background of particular concern is diffusion of {sup 222}Rn during manufacturing, leading to {sup 210}Pb contamination. The maximum acceptable concentrations in the DEAP-3600 acrylic vessel are ppt levels of {sup 238}U and {sup 232}Th equivalent, and 10{sup −8} ppt {sup 210}Pb. The impurities in the bulk acrylic will be measured by vaporizing a large quantity of acrylic and counting the concentrated residue with ultra-low background HPGe detectors and a low background alpha spectrometer. An overview of the acrylic assay technique is presented.

  19. 21 CFR 177.1310 - Ethylene-acrylic acid copolymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ethylene-acrylic acid copolymers. 177.1310 Section... Use Food Contact Surfaces § 177.1310 Ethylene-acrylic acid copolymers. The ethylene-acrylic acid... for use in contact with food subject to the provisions of this section. (a) The ethylene-acrylic...

  20. 21 CFR 177.1060 - n-Alkylglutarimide/acrylic copolymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false n-Alkylglutarimide/acrylic copolymers. 177.1060... Use Food Contact Surfaces § 177.1060 n-Alkylglutarimide/acrylic copolymers. n-Alkylglutarimide/acrylic...) Identity. For the purpose of this section, n-alkylglutarimide/acrylic copolymers are copolymers obtained...

  1. Formation of acrylic acid from lactic acid in supercritical water

    SciTech Connect

    Mok, W.S.L.; Antal, M.J. Jr. ); Jones, M. Jr. )

    1989-09-15

    Supercritical (SC) water is an unusual medium in which fast and specific heterolytic reactions can be conducted at temperatures as high as 400{degree}C. In supercritical water, lactic acid decomposes into gaseous and liquid products via three primary reaction pathways. Products of the acid-catalyzed heterolytic decarbonylation pathway are carbon monoxide, water, and acetaldehyde. Products of the homolytic, decarboxylation pathway are carbon dioxide, hydrogen, and acetaldehyde. Products of the heterolytic, dehydration pathway are acrylic acid and water. The intramolecular nucleophilic displacement of the {alpha}-hydroxyl by the carbonyl group of lactic acid, producing {alpha}-propiolactone as an unstable intermediate which subsequently rearranges to become the unsaturated acid, is a likely mechanism for acrylic acid formation, although an intramolecular E2 elimination initiated by attack of the carbonyl oxygen on a methyl hydrogen cannot be ruled out. Support for the former mechanism comes in part from the observed 100% relative yield of acrylic acid from {beta}-propiolactone in SC water.

  2. Crystal structure transformation in potassium acrylate

    NASA Astrophysics Data System (ADS)

    Pai Verneker, V. R.; Vasanthakumari, R.

    1983-10-01

    Potassium acrylate undergoes a reversible phase transformation around 335°K with an activation energy of 133 kcal/mole. Differential scanning calorimetry and high temperature X-ray powder diffraction techniques have been used to probe this phenomenon.

  3. EPMA observation between dentin and resin interfaces. Part 1. Comparison of wet and dry technique after short-term stored in water.

    PubMed

    Han, Linlin; Okamoto, Akira; Ishikawa, Kazuyuki; Iwaku, Masaaki

    2003-06-01

    The study was to evaluate the marginal leakage of wet or dry dentin condition after restoration on short-term. In the study we used Photobond adhesive system and Single Bond adhesive system. The specimens were prepared from premolars. A class V cavity was prepared at the CEJ with a high-speed hand piece and #010 round diamond point. The cavity's walls and floors were etched with phosphoric acids of the test materials by wet and dry bonding techniques. The specimens were cross-sectioned longitudinally through the center of the cavities with a low speed diamond micro-cutter and polished with carbide paper (#600-1200) after storage in distilled water for 1 day, and silver nitrate staining. Specimens were viewed with EPMA for elemental distribution of calcium, nitrogen and silver on the resin-dentin interface. The uptake of silver particles was less in samples treated with the wet-bonding technique when compared with dry-bonding technique. This in vitro study showed that bonding technique is important in establishing a seal along the restoration margins to control marginal leakage.

  4. Evaluation of heat-cured resin bases following the addition of denture teeth using a second heat cure.

    PubMed

    Polukoshko, K M; Brudvik, J S; Nicholls, J I; Smith, D E

    1992-04-01

    This study compared heat-cured acrylic resin denture baseplate distortions following a second heat cure used to add the denture teeth. The second heat cure was done with three different water-bath curing temperatures. The distortions were evaluated in three planes by use of a measuring microscope. Recorded distortions were not clinically significant.

  5. 78 FR 11627 - Certain Granular Polytetrafluoroethylene Resin From Italy: Rescission of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-19

    ... International Trade Administration Certain Granular Polytetrafluoroethylene Resin From Italy: Rescission of... on certain granular polytetrafluoroethylene (``PTFE'') resin from Italy. The period of review is... and Countervailing Duty Administrative Reviews and Request for Revocation in Part, 77 FR...

  6. Fiber reinforced composite resin systems.

    PubMed

    Giordano, R

    2000-01-01

    The Targis/Vectris and Sculpture/FibreKor systems were devised to create a translucent maximally reinforced resin framework for fabrication of crowns, bridges, inlays, and onlays. These materials are esthetic, have translucency similar to castable glass-ceramics such as OPC and Empress, and have fits that are reported to be acceptable in clinical and laboratory trials. These restorations rely on proper bonding to the remaining tooth structure; therefore, careful attention to detail must be paid to this part of the procedure. Cementation procedures should involve silane treatment of the cleaned abraded internal restoration surface, application of bonding agent to the restoration as well as the etched/primed tooth, and finally use of a composite resin. Each manufacturer has a recommended system which has been tested for success with its resin system. These fiber reinforced resins are somewhat different than classical composites, so not all cementation systems will necessarily work with them. Polishing of the restoration can be accomplished using diamond or alumina impregnated rubber wheels followed by diamond paste. The glass fibers can pose a health risk. They are small enough to be inhaled and deposited in the lungs, resulting in a silicosis-type problem. Therefore, if fibers are exposed and ground on, it is extremely important to wear a mask. Also, the fibers can be a skin irritant, so gloves also should be worn. If the fibers become exposed intraorally, they can cause gingival inflammation and may attract plaque. The fibers should be covered with additional composite resin. If this cannot be accomplished, the restoration should be replaced. The bulk of these restorations are formed using a particulate filled resin, similar in structure to conventional composite resins. Therefore, concerns as to wear resistance, color stability, excessive expansion/contraction, and sensitivity remain until these materials are proven in long-term clinical trials. They do hold the

  7. NITRATE CONVERSION OF HB-LINE REILLEXTM HPQ RESIN

    SciTech Connect

    Steimke, J.; Williams, M.; Steeper, T.; Leishear, R.

    2012-05-29

    Reillex{trademark} HPQ ion exchange resin is used by HB Line to remove plutonium from aqueous streams. Reillex{trademark} HPQ resin currently available from Vertellus Specialties LLC is a chloride ionic form, which can cause stress corrosion cracking in stainless steels. Therefore, HB Line Engineering requested that Savannah River National Laboratory (SRNL) convert resin from chloride form to nitrate form in the Engineering Development Laboratory (EDL). To perform this task, SRNL treated two batches of resin in 2012. The first batch of resin from Reilly Industries Batch 80302MA was initially treated at SRNL in 2001 to remove chloride. This batch of resin, nominally 30 liters, has been stored wet in carboys since that time until being retreated in 2012. The second batch of resin from Batch 23408 consisted of 50 kg of new resin purchased from Vertellus Specialties in 2012. Both batches were treated in a column designed to convert resin using downflow of 1.0 M sodium nitrate solution through the resin bed followed by rinsing with deionized water. Both batches were analyzed for chloride concentration, before and after treatment, using Neutron Activation Analysis (NAA). The resin specification [Werling, 2003] states the total chlorine and chloride concentration shall be less than 250 ppm. The resin condition for measuring this concentration is not specified; however, in service the resin would always be fully wet. Measurements in SRNL showed that changing from oven dry resin to fully wet resin, with liquid in the particle interstices but no supernatant, increases the total weight by a factor of at least three. Therefore, concentration of chlorine or chloride expressed as parts per million (ppm) decreases by a factor of three. Therefore, SRNL recommends measuring chlorine concentration on an oven dry basis, then dividing by three to estimate chloride concentration in the fully wet condition. Chloride concentration in the first batch (No.80302MA) was nearly the same

  8. [Radiopacity of composite resins].

    PubMed

    Tamburús, J R

    1990-01-01

    The author studied the radiopacity of six composite resins, submitted to radiographic examination in standardized conditions, only with kilovoltage variations. Along with resins it was radiographed an aluminium penetrometer, to compare their optical densities. The results showed that kilovoltagem variations interfered in optical densities of the resins, being more pronounced in 50-55, 55-60 and 60-65 kilovoltages. Despite this, the relations of optical densities as compared with that of penetrometer steps kept unaltered most fo the kilovoltages used.

  9. Polyester Resin Hazards

    PubMed Central

    Bourne, L. B.; Milner, F. J. M.

    1963-01-01

    Polyester resins are being increasingly used in industry. These resins require the addition of catalysts and accelerators. The handling of polyester resin system materials may give rise to skin irritations, allergic reactions, and burns. The burns are probably due to styrene and organic peroxides. Atmospheric pollution from styrene and explosion and fire risks from organic peroxides must be prevented. Where dimethylaniline is used scrupulous cleanliness and no-touch technique must be enforced. Handling precautions are suggested. Images PMID:14014495

  10. Effect of resin content and substrate on the emission of BTEX and carbonyls from low-VOC water-based wall paint.

    PubMed

    Zhao, Ping; Cheng, Yu-Hsiang; Lin, Chi-Chi; Cheng, Yu-Lin

    2016-02-01

    The primary aim of this work is to explore the effect of resin content and the effect of substrate on the emission of benzene, toluene, ethylbenzene, and xylene (BTEX) and carbonyls from low-VOC water-based wall paint. Four low-volatile organic compound (VOC) paints include paints A (20% acrylic), B (30% acrylic), C (20% polyvinyl acetate), and D (30% polyvinyl acetate) were painted on stainless steel specimen for the study of resin effect. Green calcium silicate, green cement, and stainless steel were painted with paints A and C for the study of substrate effect. Concentrations of the VOCs in the chamber decreased with the elapsed time. Both resin type and resin quantity in paint had effects on VOC emissions. Paints with acrylic resin emitted less BTEX and carbonyls than paints with polyvinyl acetate resin. However, the effects of resin quantity varied with VOCs. Porous substrates were observed to interact more strongly with paints than inert substrates. Both green calcium silicate and green cement substrates have strong power of adsorption of VOCs from wall paints, namely toluene, formaldehyde, acetaldehyde, 2-butanone, methacrolein, butyraldehyde, and benzaldehyde. Some compounds like toluene, formaldehyde, and butyaldehyde were desorbed very slowly from green calcium silicate and green cement substrates.

  11. Thermally stimulated current spectra of binder resin powders for copiers: Correction for thermal shrinkage of the sample powder compactions

    NASA Astrophysics Data System (ADS)

    Ikezakt, K.; Murata, Y.

    2008-12-01

    Thermally stimulated current (TSC) spectra observed under open- circuit condition for styrene- acrylic binder resin powder compactions for toners are corrected for their thermal shrinkage during TSC observation. For this binder resin, extrinsic current from motion of powder compactions with charges due to their thermal shrinkage was found to be much more effective than the sensitivity coefficient of a TSC measuring apparatus used. Particle size dependence of charge retention power of the resin powders was also examined by using this correction method and found that it decreased with decreasing their particle size.

  12. Hydrolyzable polyester resins, varnishes and coating compositions containing the same

    DOEpatents

    Yamamori, Naoki; Yokoi, Junji; Yoshikawa, Motoyoshi

    1984-01-01

    Preparation of hydrolyzable polyester resin comprising reacting polycarboxylic acid and polyhydric alcohol components, which is characterized by using, as at least part of said polyhydric alcohol component, a metallic salt of hydroxy carboxylic acid of the formula defined and effecting the polycondensation at a temperature which is no more than the decomposition temperature of said metallic salt. The polyester resins are useful as resinous vehicle of varnishes and antifouling paints.

  13. Allergic contact dermatitis to acrylates in disposable blue diathermy pads.

    PubMed Central

    Sidhu, S. K.; Shaw, S.

    1999-01-01

    We report 2 cases of elicitation of allergic contact dermatitis to acrylates from disposable blue diathermy pads used on patients who underwent routine surgery. Their reactions were severe, and took approximately 5 weeks to resolve. Both patients gave a prior history of finger tip dermatitis following the use of artificial sculptured acrylic nails, which is a common, but poorly reported, cause of acrylate allergy. Patch testing subsequently confirmed allergies to multiple acrylates present in both the conducting gel of disposable blue diathermy pads, and artificial sculptured acrylic nails. We advocate careful history taking prior to surgery to avoid unnecessary exposure to acrylates in patients already sensitized. Images Figure 1 Figure 2 PMID:10364952

  14. Hydraulic Permeability of Resorcinol-Formaldehyde Resin

    SciTech Connect

    Taylor, Paul Allen

    2010-01-01

    An ion exchange process using spherical resorcinol-formaldehyde (RF) resin is the baseline process for removing cesium from the dissolved salt solution in the high-level waste tanks at the Hanford Site, using large scale columns as part of the Waste Treatment Plant (WTP). The RF resin is also being evaluated for use in the proposed small column ion exchange (SCIX) system, which is an alternative treatment option at Hanford and at the Savannah River Site (SRS). A recirculating test loop with a small ion exchange column was used to measure the effect of oxygen uptake and radiation exposure on the permeability of a packed bed of the RF resin. The lab-scale column was designed to be prototypic of the proposed Hanford columns at the WTP. Although the test equipment was designed to model the Hanford ion exchange columns, the data on changes in the hydraulic permeability of the resin will also be valuable for determining potential pressure drops through the proposed SCIX system. The superficial fluid velocity in the lab-scale test (3.4-5.7 cm/s) was much higher than is planned for the full-scale Hanford columns to generate the maximum pressure drop expected in those columns (9.7 psig). The frictional drag from this high velocity produced forces on the resin in the lab-scale tests that matched the design basis of the full-scale Hanford column. Any changes in the resin caused by the radiation exposure and oxygen uptake were monitored by measuring the pressure drop through the lab-scale column and the physical properties of the resin. Three hydraulic test runs were completed, the first using fresh RF resin at 25 C, the second using irradiated resin at 25 C, and the third using irradiated resin at 45 C. A Hanford AP-101 simulant solution was recirculated through a test column containing 500 mL of Na-form RF resin. Known amounts of oxygen were introduced into the primary recirculation loop by saturating measured volumes of the simulant solution with oxygen and reintroducing

  15. Effect of Nanosilver on Thermal and Mechanical Properties of Acrylic Base Complete Dentures

    PubMed Central

    Hamedi-Rad, Fahimeh; Ghaffari, Tahereh; Rezaii, Farzad; Ramazani, Ali

    2014-01-01

    Objective: Polymethyl methacrylate (PMMA), widely used as a prosthodontic base, has many disadvantages, including a high thermal expansion coefficient and low thermal conductivity, a low elasticity coefficient, low impact strength and low resistance to fatigue. This study aimed to make an in vitro comparison of the thermal conductivity, compressive strength, and tensile strength of the acrylic base of complete dentures with those of acrylic reinforced with nanosilver. Materials and Methods: For this study, 36 specimens were prepared. The specimens were divided into three groups of 12; which were further divided into two subgroups of control (unmodified PMMA) and test (PMMA mixed with 5 weight% nanosilver).The results were analysed by Independent t-test. Results: This study showed that the mean thermal conductivity and compressive strength of PMMA reinforced with nanosilver were significantly higher than the unmodified PMMA (P<0.05), while the tensile strength decreased significantly after the incorporation of nanosilver (P<0.05). Conclusion: Considering our results suggesting the favorable effect of silver nanoparticles on improving the thermal conductivity and compressive strength of PMMA, use of this material in the palatal area of maxillary acrylic resin dentures is recommended. PMID:25628675

  16. The impact of polymerization method on tensile bond strength between denture base and acrylic teeth.

    PubMed

    Hashem, Mohamed; Binmgren, Mohammed A; Alsaleem, Samah O; Vellappally, Sajith; Assery, Mansour K; Sukumaran, Anil

    2014-05-01

    Failure of the bond between acrylic teeth and the denture base resin interface is one of the major concern in prosthodontics. The new generation of denture bases that utilize alternate polymerization methods are being introduced in the market. The aim of the study is to evaluate the influence of polymerization methods on bonding quality between the denture base and artificial teeth. Sixty test specimens were prepared (20 in each group) and were polymerized using heat, microwave and visible light curing. The tensile strength was recorded for each of the samples, and the results were analyzed statistically. The light-activated Eclipse™ System showed the highest tensile strength, followed by heat curing. The microwave-cured samples exhibited the least bonding to the acrylic teeth. Within the limitations of this study, it can be concluded that the new generation of light-cured denture bases showed significantly better bonding to acrylic teeth and can be used as an alternative to the conventional heat-polymerized denture base.

  17. The impact of polymerization method on tensile bond strength between denture base and acrylic teeth.

    PubMed

    Hashem, Mohamed; Binmgren, Mohammed A; Alsaleem, Samah O; Vellappally, Sajith; Assery, Mansour K; Sukumaran, Anil

    2014-01-01

    Failure of the bond between acrylic teeth and the denture base resin interface is one of the major concern in prosthodontics. The new generation of denture bases that utilize alternate polymerization methods are being introduced in the market. The aim of the study is to evaluate the influence of polymerization methods on bonding quality between the denture base and artificial teeth. Sixty test specimens were prepared (20 in each group) and were polymerized using heat, microwave and visible light curing. The tensile strength was recorded for each of the samples, and the results were analyzed statistically. The light-activated Eclipse™ System showed the highest tensile strength, followed by heat curing. The microwave-cured samples exhibited the least bonding to the acrylic teeth. Within the limitations of this study, it can be concluded that the new generation of light-cured denture bases showed significantly better bonding to acrylic teeth and can be used as an alternative to the conventional heat-polymerized denture base. PMID:25307813

  18. Acrylic coatings exhibiting improved hardness, solvent resistance and glossiness by using silica nano-composites

    NASA Astrophysics Data System (ADS)

    Dashtizadeh, Ahmad; Abdouss, Majid; Mahdavi, Hossein; Khorassani, Manuchehr

    2011-01-01

    To prepare nano-composite emulsion acrylic resins with improved surface hardness and solvent resistance, nano-silica particles were treated with surfactants. The monomers of methyl methacrylate/butylacrylate were co-polymerized on the surface of dispersed silica particles. Several emulsions with different silica contents and copolymer mole fractions were prepared. Finally the emulsions were modified to water-based acrylic coatings and improved properties such as surface hardness, solvent resistance and glossiness were determined. The study of coatings was directed to find the improved resin by optimum surface properties. Size distribution and morphology of latexes were characterized by Fourier transform infrared spectroscopy, dynamic light scattering, transmission electron microscopy and scanning electron microscopy. The glass transition temperature of nano-composites was measured and discussed its relation with silica contents, monomer mole fractions and improved properties of coatings. The optimum pendulum hardness of coatings was on 0.46 methyl methacrylate mole fraction and 120 g silica content. An increase in pendulum hardness of nano-composites with the addition of modified silica was observed. DLS and TEM studies indicate that silica particles were dispersed homogenously through the polymer matrix.

  19. Application of light-cured dental adhesive resin for mounting electrodes or microdialysis probes in chronic experiments.

    PubMed

    Okumura, Tetsu; Okanoya, Kazuo; Tani, Jun

    2007-01-01

    In chronic recording experiments, self-curing dental acrylic resins have been used as a mounting base of electrodes or microdialysis-probes. Since these acrylics do not bond to the bone, screws have been used as anchors. However, in small experimental animals like finches or mouse, their craniums are very fragile and can not successfully hold the anchors. In this report, we propose a new application of light-curing dental resins for mounting base of electrodes or microdialysis probes in chronic experiments. This material allows direct bonding to the cranium. Therefore, anchor screws are not required and surgical field can be reduced considerably. Past experiences show that the bonding effect maintains more than 2 months. Conventional resin's window of time when the materials are pliable and workable is a few minutes. However, the window of working time for these dental adhesives is significantly wider and adjustable.

  20. Delayed cure bismaleimide resins

    DOEpatents

    Not Available

    1982-08-12

    Prior art polybismaleimides begin to polymerize at or just above the melting point of the monomer. This patent describes new bismaleimide resins which have an increased pot life and provide longer time periods in which the monomer remains fluid. The resins can be polymerized into molded articles with a high uniformity of properties. (DLC)

  1. Erosion of composite resins.

    PubMed

    Powers, J M; Fan, P L

    1980-05-01

    The surface degradation of composite resins caused by accelerated aging was studied. Accelerated aging for 900 hours caused erosion of the resin matrices and exposure of filler particles. Differences in surface profiles after aging suggest that the materials eroded at different rates. Accelerated aging may model erosive wear of composites.

  2. Incombustible resin composition

    NASA Technical Reports Server (NTRS)

    Akima, T.

    1982-01-01

    Incombustible resin compositions composed of aromatic compounds were obtained through (1) combustion polymer material and (2) bisphenol A or halogenated bisphenol A and bisphenol A diglycidl ether or halogenated bisphenol A diglycidyl ether. The aromatic compound is an adduct of bifunctional phenols and bifunctional epoxy resins.

  3. Visualization study on distortion of a metal frame by polymerization shrinkage and thermal contraction of resin.

    PubMed

    Kakino, Ken; Endo, Kazuhiko; Hashimoto, Masanori; Furuta, Kunihiko; Ohno, Hiroki

    2014-01-01

    Three types of metal specimens (ring-shaped, plate-shaped, and a simulated anterior arch) for distortion observations were made from Au-Ag-Pd-Cu alloy. Distortion due to polymerization shrinkage and thermal contraction of a heat-curing acrylic resin containing 4-META (4-methacryloyloxyethyl trimellitate anhydride, 4-META resin) could be visualized for the ring-shaped specimen, which showed increasing distortion of the metal frame upon adhesion of the resin to the outer metal surface. Distortion of the plateshaped specimen adhering to 4-META resin decreased with increasing thickness of the cured resin. The distortion of the metal frame simulating an anterior arch of a six-unit bridge with a facing composite resin showed that the curvature of the metal frame was larger after curing of the facing composite resin. However, it recovered most of its original curvature with an associated increase in the number of cracks between the crowns after trimming the resin to a tooth profile. PMID:24492122

  4. Visualization study on distortion of a metal frame by polymerization shrinkage and thermal contraction of resin.

    PubMed

    Kakino, Ken; Endo, Kazuhiko; Hashimoto, Masanori; Furuta, Kunihiko; Ohno, Hiroki

    2014-01-01

    Three types of metal specimens (ring-shaped, plate-shaped, and a simulated anterior arch) for distortion observations were made from Au-Ag-Pd-Cu alloy. Distortion due to polymerization shrinkage and thermal contraction of a heat-curing acrylic resin containing 4-META (4-methacryloyloxyethyl trimellitate anhydride, 4-META resin) could be visualized for the ring-shaped specimen, which showed increasing distortion of the metal frame upon adhesion of the resin to the outer metal surface. Distortion of the plateshaped specimen adhering to 4-META resin decreased with increasing thickness of the cured resin. The distortion of the metal frame simulating an anterior arch of a six-unit bridge with a facing composite resin showed that the curvature of the metal frame was larger after curing of the facing composite resin. However, it recovered most of its original curvature with an associated increase in the number of cracks between the crowns after trimming the resin to a tooth profile.

  5. [Comparative study of tensile strength of enamel/resin/metal interface. Effect of bonding resins, retention mechanisms and metal alloys].

    PubMed

    Camparis Bussadori, C M; de Angelis Porto, C L

    1990-01-01

    The purpose of this study was to compare the enamel/resin/metal bond tensile strength by using human canines, in which castings were bonded. These castings were obtained by Co-Cr or Ni-Cr alloys and showed four types of mechanisms of retention: 50 micrograms aluminum oxide abrasive, electrochemical etch, acrylic beads metal mesh. The castings were bonded utilizing Comspan Opaque and Panavia Ex. The specimens were subjected to tensile forces after 24 hours in an Instron machine. The castings subjected to 50 micrograms aluminum oxide abrasive and bonded utilizing Panavia EX showed the biggest bond tensile strength. PMID:2099553

  6. Sorption of organics from aqueous solution onto polymeric resins

    SciTech Connect

    Gusler, G.M.; Browne, T.E.; Cohen, Y. . Dept. of Chemical Engineering)

    1993-11-01

    The uptake of phenol, toluene, chlorobenzene, and benzoic acid by several polymeric resins and activated carbon was investigated experimentally. Presentation of the sorption data in terms of the number of sorbed monolayers and fractional pore volume filled indicated that, for the polymeric resins, solute uptake cannot be viewed as only a surface adsorption phenomenon. It is suggested that the aqueous phase uptake of phenol, toluene, chlorobenzene, and benzoic acid by the polymeric resins is attributable, in part, to solute absorption. The present study also suggests that solute uptake is affected by the swelling of some of the polymeric resins in water.

  7. MCF (Magnetic Compound Fluid) Polishing Process for Free-formed Resin Device using Robotic Arm

    NASA Astrophysics Data System (ADS)

    Wu, Y.; Sato, T.; Lin, W.; Yamamoto, K.; Shimada, K.

    2011-01-01

    The automatic polishing process for three-dimensional forms, such as prototype models of products made of acrylic resin, are being required to develop in order to reduce cost and time consumption. This paper proposes a new polishing technique using magnetic compound fluid (MCF) and robotic arm. Firstly, a polishing unit, which can generate a dynamic magnetic field and be attachable to the robotic arm, is developed. This unit can hold MCF slurry that acts as a flexible and restorable polishing tool for the sake of magnetic force. Secondly, the effects of the clearance between workpiece and polishing unit, the composition of MCF slurry, the relative motion, the dynamic magnetic field and the supplied amount of slurry on polishing characteristics of acrylic resin are experimentally demonstrated. As a result, the smoothest surface roughness is achieved to below 10 nm Ra in a few min, and the feasibility of polishing the free-formed device by controlling robotic arm has been confirmed.

  8. Fracture resistance of Kevlar-reinforced poly(methyl methacrylate) resin: a preliminary study.

    PubMed

    Berrong, J M; Weed, R M; Young, J M

    1990-01-01

    The reinforcing effect of Kevlar fibers incorporated in processed poly(methyl methacrylate) resin samples was studied using 0% (controls), 0.5%, 1%, and 2% by weight of the added fibers. The samples were subjected to impact testing to determine fracture resistance, and sample groups were statistically compared using an ANOVA. Each reinforced sample had significantly greater fracture resistance (P less than 0.05) than the control, and no difference was found either within or between control groups. The use of reinforcing Kevlar fibers appears to enhance the fracture resistance of acrylic resin denture base materials.

  9. Development of resins for composites by resin transfer molding

    NASA Technical Reports Server (NTRS)

    Woo, Edmund P.; Puckett, Paul M.; Maynard, Shawn J.

    1991-01-01

    Designed to cover a wide range of resin technology and to meet the near-term and long-term needs of the aircraft industry, this research has three objectives: to produce resin transfer molding (RES) resins with improved processability, to produce prepreg systems with high toughness and service temperature, and to produce new resin systems. Progress on reaching the objectives is reported.

  10. 40 CFR 721.324 - Alkoxylated acrylate polymer (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkoxylated acrylate polymer (generic... Substances § 721.324 Alkoxylated acrylate polymer (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkoxylated acrylate...

  11. 40 CFR 721.324 - Alkoxylated acrylate polymer (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkoxylated acrylate polymer (generic... Substances § 721.324 Alkoxylated acrylate polymer (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkoxylated acrylate...

  12. 40 CFR 721.324 - Alkoxylated acrylate polymer (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkoxylated acrylate polymer (generic... Substances § 721.324 Alkoxylated acrylate polymer (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkoxylated acrylate...

  13. 40 CFR 721.5325 - Nickel acrylate complex.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Nickel acrylate complex. 721.5325... Substances § 721.5325 Nickel acrylate complex. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance nickel acrylate complex (PMN P-85-1034) is subject to reporting...

  14. 40 CFR 721.5325 - Nickel acrylate complex.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Nickel acrylate complex. 721.5325... Substances § 721.5325 Nickel acrylate complex. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance nickel acrylate complex (PMN P-85-1034) is subject to reporting...

  15. 40 CFR 721.5325 - Nickel acrylate complex.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Nickel acrylate complex. 721.5325... Substances § 721.5325 Nickel acrylate complex. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance nickel acrylate complex (PMN P-85-1034) is subject to reporting...

  16. 40 CFR 721.5325 - Nickel acrylate complex.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Nickel acrylate complex. 721.5325... Substances § 721.5325 Nickel acrylate complex. Link to an amendment published at 79 FR 34637, June 18, 2014... nickel acrylate complex (PMN P-85-1034) is subject to reporting under this section for the...

  17. 40 CFR 721.5325 - Nickel acrylate complex.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Nickel acrylate complex. 721.5325... Substances § 721.5325 Nickel acrylate complex. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance nickel acrylate complex (PMN P-85-1034) is subject to reporting...

  18. 21 CFR 177.1310 - Ethylene-acrylic acid copolymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ethylene-acrylic acid copolymers. 177.1310 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1310 Ethylene-acrylic acid copolymers. The ethylene-acrylic acid copolymers identified in paragraph (a) of this section may be...

  19. 21 CFR 177.1310 - Ethylene-acrylic acid copolymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-acrylic acid copolymers. 177.1310 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1310 Ethylene-acrylic acid copolymers. The ethylene-acrylic acid copolymers identified in paragraph (a) of this section may be...

  20. 21 CFR 177.1310 - Ethylene-acrylic acid copolymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ethylene-acrylic acid copolymers. 177.1310 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1310 Ethylene-acrylic acid copolymers. The ethylene-acrylic acid copolymers identified in paragraph (a) of this section may be...

  1. 40 CFR 721.10537 - Acrylate ester (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Acrylate ester (generic). 721.10537... Substances § 721.10537 Acrylate ester (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as acrylate ester (PMN P-01-579) is subject...

  2. 40 CFR 721.10477 - Acrylate ester (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Acrylate ester (generic). 721.10477... Substances § 721.10477 Acrylate ester (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as acrylate ester (PMN P-04-290) is subject...

  3. 40 CFR 721.10477 - Acrylate ester (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Acrylate ester (generic). 721.10477... Substances § 721.10477 Acrylate ester (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as acrylate ester (PMN P-04-290) is subject...

  4. 40 CFR 721.10537 - Acrylate ester (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Acrylate ester (generic). 721.10537... Substances § 721.10537 Acrylate ester (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as acrylate ester (PMN P-01-579) is subject...

  5. 21 CFR 177.1320 - Ethylene-ethyl acrylate copolymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... prescribed for polyethylene in § 177.1520. (1) Specifications—(i) Infrared identification. Ethylene-ethyl acrylate copolymers can be identified by their characteristic infrared spectra. (ii) Quantitative determination of ethyl acrylate content. The ethyl acrylate can be determined by the infrared spectra. Prepare...

  6. 21 CFR 177.1320 - Ethylene-ethyl acrylate copolymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... prescribed for polyethylene in § 177.1520. (1) Specifications—(i) Infrared identification. Ethylene-ethyl acrylate copolymers can be identified by their characteristic infrared spectra. (ii) Quantitative determination of ethyl acrylate content. The ethyl acrylate can be determined by the infrared spectra. Prepare...

  7. 40 CFR 721.324 - Alkoxylated acrylate polymer (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkoxylated acrylate polymer (generic... Substances § 721.324 Alkoxylated acrylate polymer (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkoxylated acrylate...

  8. 40 CFR 721.324 - Alkoxylated acrylate polymer (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkoxylated acrylate polymer (generic... Substances § 721.324 Alkoxylated acrylate polymer (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkoxylated acrylate...

  9. 40 CFR 721.484 - Fluorinated acrylic copolymer (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Fluorinated acrylic copolymer (generic... Specific Chemical Substances § 721.484 Fluorinated acrylic copolymer (generic name). (a) Chemical substance... fluorinated acrylic copolymer (PMN P-95-1208) is subject to reporting under this section for the...

  10. 40 CFR 721.484 - Fluorinated acrylic copolymer (generic name).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Fluorinated acrylic copolymer (generic... Specific Chemical Substances § 721.484 Fluorinated acrylic copolymer (generic name). (a) Chemical substance... fluorinated acrylic copolymer (PMN P-95-1208) is subject to reporting under this section for the...

  11. 40 CFR 721.10180 - Trifunctional acrylic ester (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Trifunctional acrylic ester (generic... Specific Chemical Substances § 721.10180 Trifunctional acrylic ester (generic). (a) Chemical substance and... acrylic ester (PMN P-04-692) is subject to reporting under this section for the significant new...

  12. 40 CFR 721.10180 - Trifunctional acrylic ester (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Trifunctional acrylic ester (generic... Specific Chemical Substances § 721.10180 Trifunctional acrylic ester (generic). (a) Chemical substance and... acrylic ester (PMN P-04-692) is subject to reporting under this section for the significant new...

  13. 21 CFR 177.1060 - n-Alkylglutarimide/acrylic copolymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false n-Alkylglutarimide/acrylic copolymers. 177.1060... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1060 n-Alkylglutarimide/acrylic copolymers. n-Alkylglutarimide/acrylic copolymers identified in this section may be safely used as...

  14. 40 CFR 721.10180 - Trifunctional acrylic ester (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Trifunctional acrylic ester (generic... Specific Chemical Substances § 721.10180 Trifunctional acrylic ester (generic). (a) Chemical substance and... acrylic ester (PMN P-04-692) is subject to reporting under this section for the significant new...

  15. 40 CFR 721.484 - Fluorinated acrylic copolymer (generic name).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Fluorinated acrylic copolymer (generic... Specific Chemical Substances § 721.484 Fluorinated acrylic copolymer (generic name). (a) Chemical substance... fluorinated acrylic copolymer (PMN P-95-1208) is subject to reporting under this section for the...

  16. 40 CFR 721.484 - Fluorinated acrylic copolymer (generic name).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Fluorinated acrylic copolymer (generic... Specific Chemical Substances § 721.484 Fluorinated acrylic copolymer (generic name). (a) Chemical substance... fluorinated acrylic copolymer (PMN P-95-1208) is subject to reporting under this section for the...

  17. 21 CFR 177.1060 - n-Alkylglutarimide/acrylic copolymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true n-Alkylglutarimide/acrylic copolymers. 177.1060... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1060 n-Alkylglutarimide/acrylic copolymers. n-Alkylglutarimide/acrylic copolymers identified in this section may be safely used as...

  18. 21 CFR 177.1060 - n-Alkylglutarimide/acrylic copolymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false n-Alkylglutarimide/acrylic copolymers. 177.1060... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1060 n-Alkylglutarimide/acrylic copolymers. n-Alkylglutarimide/acrylic copolymers identified in this section may be safely used as...

  19. 40 CFR 721.10180 - Trifunctional acrylic ester (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Trifunctional acrylic ester (generic... Specific Chemical Substances § 721.10180 Trifunctional acrylic ester (generic). (a) Chemical substance and... acrylic ester (PMN P-04-692) is subject to reporting under this section for the significant new...

  20. 21 CFR 177.1310 - Ethylene-acrylic acid copolymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ethylene-acrylic acid copolymers. 177.1310 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1310 Ethylene-acrylic acid copolymers. The ethylene-acrylic acid copolymers identified in paragraph (a) of this section may be...

  1. 40 CFR 721.484 - Fluorinated acrylic copolymer (generic name).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Fluorinated acrylic copolymer (generic... Specific Chemical Substances § 721.484 Fluorinated acrylic copolymer (generic name). (a) Chemical substance... fluorinated acrylic copolymer (PMN P-95-1208) is subject to reporting under this section for the...

  2. 40 CFR 721.10180 - Trifunctional acrylic ester (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Trifunctional acrylic ester (generic... Specific Chemical Substances § 721.10180 Trifunctional acrylic ester (generic). (a) Chemical substance and... acrylic ester (PMN P-04-692) is subject to reporting under this section for the significant new...

  3. 21 CFR 177.1060 - n-Alkylglutarimide/acrylic copolymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false n-Alkylglutarimide/acrylic copolymers. 177.1060... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1060 n-Alkylglutarimide/acrylic copolymers. n-Alkylglutarimide/acrylic copolymers identified in this section may be safely used as...

  4. Chitosan and functionalized acrylic nanoparticles as the precursor of new generation of bio-based antibacterial films.

    PubMed

    Torabi, Saeid; Mahdavian, Ali Reza; Sanei, Mahmood; Abdollahi, Amin

    2016-02-01

    This study represents a new method for preparation of acrylic/chitosan films with antibacterial activity and non-toxic properties through an environmental friendly process containing a water-base acrylic resin and chitosan as an abundant natural polymer. Functional and positively charged acrylic particles based on butyl acrylate (BA)-methyl methacrylate (MMA)-glycidyl methacrylate (GMA) terpolymer were prepared with layered structure via semi-continuous emulsion polymerization. FTIR spectroscopy confirmed the presence of epoxy functional groups and size distribution of particles were evaluated by DLS and SEM as well. Films were prepared through mixing of chitosan solution and the prepared latex for the first time. SEM and EDX analyses revealed that chitosan has been distributed through the polymeric matrix uniformly. TGA data showed that introducing chitosan increases the maximum degradation temperature. It was found that the obtained films including positively charged chitosan reveal enhanced antibacterial activity against Staphylococcus areus and Escherichia coli. Also cytotoxicity analysis shows reasonable non-toxic behavior of the obtained composite films.

  5. Chitosan and functionalized acrylic nanoparticles as the precursor of new generation of bio-based antibacterial films.

    PubMed

    Torabi, Saeid; Mahdavian, Ali Reza; Sanei, Mahmood; Abdollahi, Amin

    2016-02-01

    This study represents a new method for preparation of acrylic/chitosan films with antibacterial activity and non-toxic properties through an environmental friendly process containing a water-base acrylic resin and chitosan as an abundant natural polymer. Functional and positively charged acrylic particles based on butyl acrylate (BA)-methyl methacrylate (MMA)-glycidyl methacrylate (GMA) terpolymer were prepared with layered structure via semi-continuous emulsion polymerization. FTIR spectroscopy confirmed the presence of epoxy functional groups and size distribution of particles were evaluated by DLS and SEM as well. Films were prepared through mixing of chitosan solution and the prepared latex for the first time. SEM and EDX analyses revealed that chitosan has been distributed through the polymeric matrix uniformly. TGA data showed that introducing chitosan increases the maximum degradation temperature. It was found that the obtained films including positively charged chitosan reveal enhanced antibacterial activity against Staphylococcus areus and Escherichia coli. Also cytotoxicity analysis shows reasonable non-toxic behavior of the obtained composite films. PMID:26652342

  6. Microtensile bond strength of resin-resin interfaces after 24-hour and 2-month soaking.

    PubMed

    Leavitt, Curry; Boberick, Kenneth G; Winkler, Sheldon

    2007-01-01

    Evaluate the bond strengths of denture base-repair materials to minimize recurrent failure rate. Use microtensile bond strength (muTBS) testing to evaluate the interfacial bonding strength of 6 commercial denture repair materials after 24-hour and 12-month soaking. Blocks of poly(methyl metacrylate) (PMMA) and Triad were fabricated, fractured, and repaired. Twenty bars (1 x 1 x 30 mm) per group were sectioned from each block parallel to the long axis and approximately 90 degrees to the resin-resin repair interface and stored before muTBS testing in a servo-hydraulic tensile-testing machine. Intact PMMA and Triad bars that had been soaked for 24 hours and 12 months were tested for reference. The 24-hour repair strengths for PMMA ranged from 52% to 84% of original strength. Soaking for 12 months resulted in a 20% decrease in strength for the PMMA control. The 12-month repair strengths for PMMA ranged from 43% to 74% of the 12-month soaked material strength. Triad repair tested 35% of original strength after soaking for 24 hours. Permabond (cyanoacrylate) to PMMA tested 47% of original strength after 24 hours of soaking and 26% of the 12-month soaked material strength. Permabond to Triad tested 30% of original strength after 24 hours of soaking. Permabond and Triad showed a 100% adhesive mode of failure. All other materials tested exhibited either an adhesive mode of failure at the denture base-repair-material interface or a complex cohesive failure within the repair-material interface. The muTBS approach can be used to analyze the resin-resin interface of repaired acrylics. The relatively small standard deviations make the muTBS approach attractive. In this study, muTBS was used to evaluate the repair strength of 6 denture repair materials enabling clinicians to make clinical judgments regarding the strongest repair bond available. PMID:17987865

  7. Polymer radiation curing: Polyolefins and acrylics. January 1970-July 1989 (Citations from the NTIS data base). Report for January 1970-July 1989

    SciTech Connect

    Not Available

    1989-08-01

    This bibliography contains citations concerning electromagnetic radiation curing of polyolefin and acrylic polymeric resins. Processes for crosslinking by gamma, ultraviolet, and infrared radiation are emphasized; however, microwave, laser, vacuum irradiation, and ionization radiation are examined as well. The influence of radiation-induced polymer crosslinking on such properties as thermal conductivity, stress/strain, electrical conductivity, tensile and impact strength is also included. (This updated bibliography contains 308 citations, 15 of which are new entries to the previous edition.)

  8. Polymer radiation curing: polyolefins and acrylics. January 1970-December 1987 (citations from the NTIS data base). Report for January 1970-December 1987

    SciTech Connect

    Not Available

    1988-01-01

    This bibliography contains citations concerning electromagnetic radiation curing of polyolefin and acrylic polymeric resins. Processes for crosslinking by gamma, ultraviolet, and infrared radiation are emphasized; however, microwave, laser, vacuum irradiation, and ionization radiation are examined as well. The influence of radiation induced polymer crosslinking on such properties as thermal conductivity, stress/strain, electrical conductivity, tensile and impact strength is also included. (This updated bibliography contains 231 citations, 15 of which are new entries to the previous edition.)

  9. Biocidal quaternary ammonium resin

    NASA Technical Reports Server (NTRS)

    Janauer, G. E.

    1983-01-01

    Activated carbon (charcoal) and polymeric resin sorbents are widely used in the filtration and treatment of drinking water, mainly to remove dissolved organic and inorganic impurities and to improve the taste. Earlier hopes that activated carbon might "disinfect' water proved to be unfounded. The feasibility of protecting against microbial infestation in charcoal and resin beds such as those to be incorporated into total water reuse systems in spacecraft was investigated. The biocidal effect of IPCD (insoluable polymeric contact disinfectants) in combination with a representative charcoal was assessed. The ion exchange resins (IPCD) were shown to adequately protect charcoal and ion exchange beds.

  10. Acrylic Tanks for Stunning Chemical Demonstrations

    ERIC Educational Resources Information Center

    Mirholm, Alexander; Ellervik, Ulf

    2009-01-01

    We describe the use of acrylic tanks (400 x 450 x 27 mm) for visualization of chemical demonstrations in aqueous solutions. Examples of well-suited demonstrations are oscillating reactions, pH indicators, photochemical reduction of Lauth's violet, and chemoluminiscent reactions. (Contains 1 figure.)

  11. 40 CFR 721.405 - Polyether acrylate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 721.405 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.405 Polyether acrylate. (a) Chemical substance and significant new uses subject to reporting....

  12. 40 CFR 721.405 - Polyether acrylate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 721.405 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.405 Polyether acrylate. (a) Chemical substance and significant new uses subject to reporting....

  13. UV-curable acrylated coating from epoxidized palm oil

    NASA Astrophysics Data System (ADS)

    Rahman, Nurliyana Abd; Badri, Khairiah Haji; Salleh, Nik Ghazali Nik

    2014-09-01

    The properties of coating film prepared from the incorporation of acrylated palm oil (EPOLA) in commercial epoxy acrylate have been studied. A series of different amount of EPOLA was mixed with commercial epoxy acrylate. The blended acrylates passed through UV light to produce a non-tacky film. The conversion of acrylate double bond was monitored by FTIR. The effect of EPOLA concentration onto coated films were investigated by determination of the pendulum hardness and gel content. The higher the amount of EPOLA, the lower the pendulum hardness and the gel content but to a level acceptable for usage in the high-end applications.

  14. CHARACTERIZATION OF CYCLED SPHERICAL RESORCINOL-FORMALDEHYDE ION EXCHANGE RESIN

    SciTech Connect

    Nash, C.; Duignan, M.

    2010-02-23

    work to quantify mercury on sRF resin. Resin mercury content is important in plans for the disposition of used sRF resin. Mercury speciation in high level waste (HLW) is unknown. It may be partly organic, one example being methyl mercury cation. Further study of the resin's affinity for mercury is recommended.

  15. Modeling of process-induced residual stresses and resin flow behavior in resin transfer molded composites with woven fiber mats

    NASA Astrophysics Data System (ADS)

    Golestanian, Hossein

    This research focuses on modeling Resin Transfer Molding process for manufacture of composite parts with woven fiber mats. Models are developed to determine cure dependent stiffness matrices for composites manufactured with two types of woven fiber mats. Five-harness carbon and eight-harness fiberglass mats with EPON 826 resin composites are considered. The models presented here take into account important material/process parameters with emphasis on; (1) The effects of cure-dependent resin mechanical properties, (2) Fiber undulation due to the weave of the fiber fill and warp bundles, and (3) Resin interaction with the fiber bundles at a microscopic scale. Cure-dependent mechanical properties were then used in numerical models to determine residual stresses and deformation in the composite parts. The complete cure cycle was modeled in these analyses. Also the cool down stage after the composite cure was analyzed. The effect of 5% resin shrinkage on residual stresses and deformations was also investigated. In the second part of the study, Finite Element models were developed to simulate mold filling in RTM processes. Resin flow in the fiber mats was modeled as flow through porous media. Physical models were also developed to investigate resin flow behavior into molds of rectangular and irregular shapes. Silicone fluids of 50 and 100 centistoke viscosities as well as EPON 826 epoxy resin were used in the mold filling experiments. The reinforcements consisted of several layers of woven fiberglass and carbon fiber mats. The effects of injection pressure, fluid viscosity, type of reinforcement, and mold geometry on mold filling times were investigated. Fiber mat permeabilities were determined experimentally for both types of reinforcements. Comparison of experimental and numerical resin front positions indicated the importance of edge effects in resin flow behavior in small cavities. The resin front positions agreed well for the rectangular mold geometry.

  16. Comparative Evaluation of Effect of Water Absorption on the Surface Properties of Heat Cure Acrylic: An in vitro Study

    PubMed Central

    Chandu, G S; Asnani, Pooja; Gupta, Siddarth; Faisal Khan, Mohd.

    2015-01-01

    Background: Use of alkaline peroxide denture cleanser with different temperature of water could cause a change in surface hardness of the acrylic denture and also has a bleaching effect. The purpose of the study was to determine the effect of increased water content during thermal cycling of hot water-treated acrylic on the surface hardness of acrylic denture base when compared to warm water treated acrylic. And to compare the bleaching effect of alkaline peroxide solution on the acrylic denture base on hot water and warm water treated acrylic. Materials and Methods: Forty samples (10 mm × 10 mm × 2.5 mm) were prepared. After the calculation of the initial hardness 40 samples, each was randomly assigned to two groups. Group A: 20 samples were immersed in 250 ml of warm distilled water at 40°C with alkaline peroxide tablet. Group B: 20 samples were immersed in 250 ml of hot distilled water at 100°C with alkaline peroxide tablet. The surface hardness of each test sample was obtained using the digital hardness testing machine recording the Rockwell hardness number before the beginning of the soaking cycles and after completion of 30 soak cycles and compared. Values were analyzed using paired t-test. Five samples from the Group A and five samples from Group B were put side by side and photographed using a Nikon D 40 digital SLR Camera and the photographs were examined visually to assess the change in color. Results: Acrylic samples immersed in hot water showed a statistically significant decrease of 5.8% in surface hardness. And those immersed in warm water showed a statistically insignificant increase of 0.67% in surface hardness. Samples from the two groups showed clinically insignificant difference in color when compared to each other on examination of the photographs. Conclusion: Thermocycling of the acrylic resin at different water bath temperature at 40°C and 100°C showed significant changes in the surface hardness. PMID:25954074

  17. Large Acrylic Spherical Windows In Hyperbaric Underwater Photography

    NASA Astrophysics Data System (ADS)

    Lones, Joe J.; Stachiw, Jerry D.

    1983-10-01

    Both acrylic plastic and glass are common materials for hyperbaric optical windows. Although glass continues to be used occasionally for small windows, virtually all large viewports are made of acrylic. It is easy to uderstand the wide use of acrylic when comparing design properties of this plastic with those of glass, and glass windows are relatively more difficult to fabricate and use. in addition there are published guides for the design and fabrication of acrylic windows to be used in the hyperbaric environment of hydrospace. Although these procedures for fabricating the acrylic windows are somewhat involved, the results are extremely reliable. Acrylic viewports are now fabricated to very large sizes for manned observation or optical quality instrumen tation as illustrated by the numerous acrylic submersible vehicle hulls for hu, an occupancy currently in operation and a 3600 large optical window recently developed for the Walt Disney Circle Vision under-water camera housing.

  18. Synthesis and swelling properties of β-cyclodextrin-based superabsorbent resin with network structure.

    PubMed

    Huang, Zhanhua; Liu, Shouxin; Fang, Guizhen; Zhang, Bin

    2013-02-15

    A biodegradable, β-cyclodextrin-based superabsorbent resin was synthesized by the inverse suspension method. The microstructure, chemical structure, and thermal performance of the resin were characterized by scanning electron microscopy, Fourier transform-infrared spectroscopy, and differential scanning calorimetry. The effects of the synthesis conditions (dosage of cross-linking agent, mass ratios of acrylic acid to acrylamide, mass ratios of β-cyclodextrin to total monomer, neutralization degree, initiator dosage, and reaction time) were optimized to achieve a resin with a maximum swelling capacity. The water absorbency of the optimized resin in distilled water was 1544.76 g/g and that in 0.9 wt.% NaCl was 144.52 g/g. The resin, which is thermoplastic as well as pH-sensitive, had good salt resistance and underwent a maximum in swelling with time in CaCl(2) and AlCl(3) solutions. The fracture surface of the dry resin contained many pores. After swelling, the internal hydrogel showed a typical three-dimensional network structure. The biodegradation of the resin reached 71.2% after 18 days treatment at 30 °C with Lentinus edodes. PMID:23399293

  19. Polyethyleneimine nanoparticles incorporated into resin composite cause cell death and trigger biofilm stress in vivo.

    PubMed

    Beyth, Nurit; Yudovin-Farber, Ira; Perez-Davidi, Michael; Domb, Abraham J; Weiss, Ervin I

    2010-12-21

    Incorporation of cross-linked quaternary ammonium polyethylenimine (QPEI) nanoparticles in dental resin composite has a long-lasting and wide antimicrobial effect with no measured impact on biocompatibility in vitro. We hypothesized that QPEI nanoparticles incorporated into a resin composite have a potent antibacterial effect in vivo and that this stress condition triggers a suicide module in the bacterial biofilm. Ten volunteers wore a removable acrylic appliance, in which two control resin composite specimens and two resin composite specimens incorporating 1% wt/wt QPEI nanoparticles were inserted to allow the buildup of intraoral biofilms. After 4 h, the specimens were removed and tested for bacterial vitality and biofilm thickness, using confocal laser scanning microscopy. The vitality rate in specimens incorporating QPEI was reduced by > 50% (p < 0.00001), whereas biofilm thickness was increased (p < 0.05). The ability of the biofilm supernatant to restore bacterial death was tested in vitro. The in vitro tests showed a 70% decrease in viable bacteria (p < 0.05). Biofilm morphological differences were also observed in the scanning electron microscope micrographs of the resin composite versus the resin composite incorporating QPEI. These results strongly suggest that QPEI nanoparticles incorporated at a low concentration in resin composite exert a significant in vivo antibiofilm activity and exhibit a potent broad spectrum antibacterial activity against salivary bacteria.

  20. Acetylene terminated matrix resins

    NASA Technical Reports Server (NTRS)

    Goldfarb, I. J.; Lee, Y. C.; Arnold, F. E.; Helminiak, T. E.

    1985-01-01

    The synthesis of resins with terminal acetylene groups has provided a promising technology to yield high performance structural materials. Because these resins cure through an addition reaction, no volatile by-products are produced during the processing. The cured products have high thermal stability and good properties retention after exposure to humidity. Resins with a wide variety of different chemical structures between the terminal acetylene groups are synthesized and their mechanical properties studied. The ability of the acetylene cured polymers to give good mechanical properties is demonstrated by the resins with quinoxaline structures. Processibility of these resins can be manipulated by varying the chain length between the acetylene groups or by blending in different amounts of reactive deluents. Processing conditions similar to the state-of-the-art epoxy can be attained by using backbone structures like ether-sulfone or bis-phenol-A. The wide range of mechanical properties and processing conditions attainable by this class of resins should allow them to be used in a wide variety of applications.

  1. 21 CFR 177.1380 - Fluorocarbon resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Materials,” which is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from the American Society for Testing and Materials, 1916 Race St., Philadelphia, PA... the resin pellets, when extracted with 100 milliliters of 50 percent (by volume) ethyl alcohol...

  2. 21 CFR 177.1585 - Polyestercarbonate resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Single Point Method Using Dichloromethane as the Solvent,” developed by the General Electric Co., September 20, 1985, which is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51... Methylene Chloride in Polyestercarbonate Resin,” developed by the General Electric Co., July 23, 1991,...

  3. 21 CFR 177.1585 - Polyestercarbonate resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Single Point Method Using Dichloromethane as the Solvent,” developed by the General Electric Co., September 20, 1985, which is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51... Methylene Chloride in Polyestercarbonate Resin,” developed by the General Electric Co., July 23, 1991,...

  4. 40 CFR 414.50 - Applicability; description of the thermosetting resins subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... *Epoxy Resins *Fumaric Acid Polyesters *Furan Resins Glyoxal-Urea Formaldehyde Textile Resin *Ketone-Formaldehyde Resins *Melamine Resins *Phenolic Resins *Polyacetal Resins Polyacrylamide *Polyurethane Prepolymers *Polyurethane Resins *Urea Formaldehyde Resins *Urea Resins...

  5. 40 CFR 414.50 - Applicability; description of the thermosetting resins subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... *Epoxy Resins *Fumaric Acid Polyesters *Furan Resins Glyoxal-Urea Formaldehyde Textile Resin *Ketone-Formaldehyde Resins *Melamine Resins *Phenolic Resins *Polyacetal Resins Polyacrylamide *Polyurethane Prepolymers *Polyurethane Resins *Urea Formaldehyde Resins *Urea Resins...

  6. 40 CFR 414.50 - Applicability; description of the thermosetting resins subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... *Epoxy Resins *Fumaric Acid Polyesters *Furan Resins Glyoxal-Urea Formaldehyde Textile Resin *Ketone-Formaldehyde Resins *Melamine Resins *Phenolic Resins *Polyacetal Resins Polyacrylamide *Polyurethane Prepolymers *Polyurethane Resins *Urea Formaldehyde Resins *Urea Resins...

  7. 40 CFR 414.50 - Applicability; description of the thermosetting resins subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... *Epoxy Resins *Fumaric Acid Polyesters *Furan Resins Glyoxal-Urea Formaldehyde Textile Resin *Ketone-Formaldehyde Resins *Melamine Resins *Phenolic Resins *Polyacetal Resins Polyacrylamide *Polyurethane Prepolymers *Polyurethane Resins *Urea Formaldehyde Resins *Urea Resins...

  8. Resin transfer molding of textile composites

    NASA Technical Reports Server (NTRS)

    Falcone, Anthony; Dursch, Harry; Nelson, Karl; Avery, William

    1993-01-01

    The design and manufacture of textile composite panels, tubes, and angle sections that were provided to NASA for testing and evaluation are documented. The textile preform designs and requirements were established by NASA in collaboration with Boeing and several vendors of textile reinforcements. The following four types of preform architectures were used: stitched uniweave, 2D-braids, 3D-braids, and interlock weaves. The preforms consisted primarily of Hercules AS4 carbon fiber; Shell RSL-1895 resin was introduced using a resin transfer molding process. All the finished parts were inspected using ultrasonics.

  9. Structural study of photodegraded acrylic-coated lime wood using Fourier transform infrared and two-dimensional infrared correlation spectroscopy.

    PubMed

    Popescu, Carmen-Mihaela; Simionescu, Bogdan C

    2013-06-01

    The weathering of acrylic films and acrylic-coated lime wood (Tillia cordata Mill.) were examined using Fourier transform infrared (FT-IR) and two-dimensional infrared correlation spectroscopy. The obtained results showed chemical changes induced by exposure to weathering conditions, in both films and coated wood. The observed spectral changes of the acrylic films refer to the absorption band assigned to the C-O stretching, which progressively decreases with increasing exposure time. In the spectra of treated wood samples the main signal indicating the advance of oxidation during the photodegradation exposure is the gradual increase and broadening of the band in the carbonyl region. This is due to the formation of the non-hydrogen bonded aliphatic carboxylic acids and γ-lactone structures in the acrylic resin and of the nonconjugated ketones, carboxyl groups, and lactones in wood. As a consequence, the increase of the 1734 cm(-1) band is due to the degradation of lignin from wood surface. These observations are also supported by the decreased intensities of the bands at 1598 and 1505 cm(-1), assigned to C=C of aromatic skeletal (lignin). The relative intensity of the characteristic aromatic lignin band at 1505 cm(-1) decreases up to 25% of its original value after weathering, being less than half of the value obtained for uncoated wood. Two-dimensional infrared (2D IR) correlation spectroscopy was used to identify the sequence of the modifications of the different stretching vibrations bands under the weathering conditions, the method allowing the prediction of the order of degradation reactions. The acrylic resin degradation starts with the formation of radicals by abstraction of the tertiary hydrogen atoms of the methyl acrylate units and the α-CH3 groups from the ethyl methacrylate units. The subsequent decomposition and oxidation led to the formation of alcohol groups, hydroperoxides, ketones, and/or carboxylic acid groups. The 2D IR correlation spectra of

  10. [Allergic contact eczema from epoxy resin].

    PubMed

    Calzado, Leticia; Ortiz-de Frutos, Francisco J; del Prado Sánchez-Caminero, María; Galera, Carmen María; Valverde, Ricardo; Vanaclocha, Francisco

    2005-11-01

    Epoxy resins are plastics that are widely used as electrical insulation, in coatings, and as adhesives and paints. They have strong sensitizing power and are one of the main causes of allergic contact eczema, both in the workplace and elsewhere. We present the case of a worker at a plastics/chemical plant, who handled aeronautical components in the process of manufacturing fuselage parts. He consulted his physician because of eczematous lesions on his fingers, hands and forearms which had developed over a two-year period and were clearly related to his work. The standard battery of skin tests was performed, along with the plastics and adhesives series and tests using the products from his workplace. Positivity was shown to epoxy resins (standard battery) and to the products from his workplace, which included different fiberglass and carbon fiber sheets impregnated with epoxy resins and epoxy adhesives.

  11. Graphite fiber reinforced thermoplastic resins

    NASA Technical Reports Server (NTRS)

    Novak, R. C.

    1975-01-01

    Mechanical properties of neat resin samples and graphite fiber reinforced samples of thermoplastic resins were characterized with particular emphasis directed to the effects of environmental exposure (humidity, temperature and ultraviolet radiation). Tensile, flexural, interlaminar shear, creep and impact strengths were measured for polysulfone, polyarylsulfone and a state-of-the-art epoxy resin samples. In general, the thermoplastic resins exhibited environmental degradation resistance equal to or superior to the reference epoxy resin. Demonstration of the utility and quality of a graphite/thermoplastic resin system was accomplished by successfully thermoforming a simulated compressor blade and a fan exit guide vane.

  12. Fiber reinforced thermoplastic resin matrix composites

    NASA Technical Reports Server (NTRS)

    Jones, Robert J. (Inventor); Chang, Glenn E. C. (Inventor)

    1989-01-01

    Polyimide polymer composites having a combination of enhanced thermal and mechanical properties even when subjected to service temperatures as high as 700.degree. F. are described. They comprise (a) from 10 to 50 parts by weight of a thermoplastic polyimide resin prepared from 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane and (b) from 90 to 50 parts by weight of continuous reinforcing fibers, the total of (a) and (b) being 100 parts by weight. Composites based on polyimide resin formed from 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane and pyromellitic dianhydride and continuous carbon fibers retained at least about 50% of their room temperature shear strength after exposure to 700.degree. F. for a period of 16 hours in flowing air. Preferably, the thermoplastic polyimide resin is formed in situ in the composite material by thermal imidization of a corresponding amide-acid polymer prepared from 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane. It is also preferred to initially size the continuous reinforcing fibers with up to about one percent by weight of an amide-acid polymer prepared from 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane. In this way imidization at a suitable elevated temperature results in the in-situ formation of a substantially homogeneous thermoplastic matrix of the polyimide resin tightly and intimately bonded to the continuous fibers. The resultant composites tend to have optimum thermo-mechanical properties.

  13. Evaluation of polymethyl methacrylate resin mechanical properties with incorporated halloysite nanotubes

    PubMed Central

    2016-01-01

    PURPOSE This study inspects the effect of incorporating halloysite nanotubes (HNTs) into polymethyl methacrylate (PMMA) resin on its flexural strength, hardness, and Young's modulus. MATERIALS AND METHODS Four groups of acrylic resin powder were prepared. One group without HNTs was used as a control group and the other three groups contained 0.3, 0.6 and 0.9 wt% HNTs. For each one, flexural strength, Young's modulus and hardness values were measured. One-way ANOVA and Tukey's test were used for comparison (P<.05). RESULTS At lower concentration (0.3 wt%) of HNT, there was a significant increase of hardness values but no significant increase in both flexural strength and Young's modulus values of PMMA resin. In contrast, at higher concentration (0.6 and 0.9 wt%), there was a significant decrease in hardness values but no significant decrease in flexural strength and Young's modulus values compared to those of the control group. CONCLUSION Addition of lower concentration of halloysite nanotubes to denture base materials could improve some of their mechanical properties. Improving the mechanical properties of acrylic resin base material could increase the patient satisfaction. PMID:27350849

  14. In-vitro Evaluation of Transverse Strength of Repaired Heat Cured Denture Base Resins without Surface Treatment and with Chemical and Mechanical Surface Treatment

    PubMed Central

    Yadav, Naveen S; Khare, Shilpi; Mishra, Sunil Kumar; Vyas, Rajesh; Mahajan, Harsh; Chitumalla, Rajkiran

    2015-01-01

    Background: Denture repair involves joining two parts of a fractured denture with a denture repair material. Hence, a substantial repairing system for denture base fracture should be there to elude frequent fracture. Materials and Methods: Surface treatment of conventional heat cure denture base resin with different surface treatments (chemical ethyl acetate, and mechanical roughening with bur), with control group formed without surface treatment. Specimens were repaired with auto polymerizing acrylic resin using sprinkle on technique. The testing of the transverse strength of the repaired specimens was evaluated with three-point bending test on universal testing machine. Results: The study revealed that surface chemical treatment with ethyl acetate improved the transverse strength of repaired heat cure denture base when compared with mechanical and control group. A two-way analysis of variance revealed that there was statistically significant difference in mean strengths of the three groups. Conclusion: Surface chemical treatment with ethyl acetate improved the transverse strength of the repaired heat cure denture base when compared with mechanical roughening with bur and group without surface treatment. PMID:26464547

  15. Intercalation of acrylic acid and sodium acrylate into kaolinite and their in situ polymerization

    NASA Astrophysics Data System (ADS)

    Zhang, Bo; Li, Yanfeng; Pan, Xiaobing; Jia, Xin; Wang, Xiaolong

    2007-02-01

    Novel nano-composites of poly (acrylic acid)-kaolinite were prepared, and intercalation and in situ polymerization were used in this process. The nano-composites were obtained by in situ polymerization of acrylic acid (AA) and sodium acrylate (AANa) intercalated into organo-kaolinite, which was obtained by refining and chemically modifying with solution intercalation step in order to increase the basal plane distance of the original clay. The modification was completed by using dimethyl-sulfoxide (DMSO)/methanol and potassium acetate (KAc)/water systems step by step. The materials were characterized with the help of XRD, FT-IR and TEM; the results confirmed that poly(acrylic acid) (PAA) and poly(sodium acrylate) (PAANa) were intercalated into the interlamellar spaces of kaolinite, the resulting copolymer composites (CC0 : copolymer crude kaolinite composite, CC1 : copolymer DMSO kaolinite composite, CC2 : copolymer KAc kaolinite composite) of CC2 exhibited a lamellar nano-composite with a mixed nano-morphology, and partial exfoliation of the intercalating clay platelets should be the main morphology. Finally, the effect of neutralization degree on the intercalation behavior was also investigated.

  16. 'Weightless' acrylic painting by Jack Kroehnke

    NASA Technical Reports Server (NTRS)

    1987-01-01

    'Weightless' acrylic painting by Jack Kroehnke depicts STS-26 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) David C. Hilmers participating in extravehicular activity (EVA) simulation in JSC Weightless Environment Training Facility (WETF) Bldg 29. In the payload bay (PLB) mockup, Hilmers, wearing extravehicular mobility unit (EMU), holds onto the mission-peculiar equipment support structure in foreground while SCUBA-equipped diver monitors activity overhead and camera operator records EVA procedures. Copyrighted art work for use by NASA.

  17. Method for removing contaminants from plastic resin

    DOEpatents

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    2008-12-09

    A resin recycling method that produces essentially contaminant-free synthetic resin material in an environmentally safe and economical manner. The method includes receiving the resin in container form. The containers are then ground into resin particles. The particles are exposed to a solvent, the solvent contacting the resin particles and substantially removing contaminants on the resin particles. After separating the particles and the resin, a solvent removing agent is used to remove any residual solvent remaining on the resin particles after separation.

  18. Bond strength of resin composite to differently conditioned amalgam.

    PubMed

    Ozcan, M; Vallittu, P K; Huysmans, M-C; Kalk, W; Vahlberg, T

    2006-01-01

    Bulk fracture of teeth, where a part of the amalgam restoration and/or the cusp is fractured, is a common clinical problem. The aim of this study was to evaluate the effect of different surface conditioning methods on the shear bond strength of a hybrid resin composite to fresh amalgam. Amalgams (N=84) were condensed into acrylic and randomly assigned to one of the following treatments (N=6): (1) Alloy primer + opaquer, (2) Air-particle abrasion (50 micro m Al(2)O(3)) + alloy primer + opaquer, (3) Silica coating (30 micro m SiO(x)) + silanization + opaquer, (4) Opaquer + pre-impregnated continuous bidirectional E-glass fibre sheets, (5) Silica coating + silanization + fibre sheets, (6) Silica coating + silanization + opaquer + fibre sheet application. Non-conditioned amalgam surfaces were considered as control group (7). The mean surface roughness depth (R(Z)) was measured from the control group and air-abraded amalgam surfaces. The resin composite was bonded to the conditioned amalgam specimens using polyethylene molds. All specimens were tested under dry and thermocycled (6.000, 5-55 degrees C, 30 s) conditions. The shear bond strength of resin composite to amalgam substrates was measured in a universal testing machine (1 mm/min). Surface roughness values for the non-conditioned control group (R(Z) approximately 0.14 micro m) and for air-particle abraded surfaces with either Al(2)O(3) or SiO(x) (R(Z) approximately 0.19 micro m and R(Z) approximately 0.16 micro m, respectively) did not show significant differences (p=0.23) (One-way ANOVA). In dry conditions, silica coating and silanization followed by fibre sheet application exhibited significantly higher results (14.8+/-5.6 MPa) than those of the groups conditioned with alloy primer (2.2+/-0.7 MPa) (p<0.001), air-particle abrasion+alloy primer (4.4+/-2.0 MPa, p<0.001), silica coating+silanization alone (6.2+/-0.8 MPa, p=0.009) or non-conditioned group (1.4+/-0.6, p<0.001). Silica coating and silanization followed

  19. Phosphonic acid based exchange resins

    DOEpatents

    Horwitz, E.P.; Alexandratos, S.D.; Gatrone, R.C.; Chiarizia, R.

    1995-09-12

    An ion exchange resin is described for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene. 10 figs.

  20. Phosphonic acid based exchange resins

    DOEpatents

    Horwitz, E. Philip; Alexandratos, Spiro D.; Gatrone, Ralph C.; Chiarizia, Ronato

    1995-01-01

    An ion exchange resin for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene.

  1. Palladium (Ii) Catalyzed Polymerization Of Norbornene And Acrylates

    DOEpatents

    Sen, Ayusman; Kacker, Smita; Hennis, April; Polley, Jennifer D.

    2001-10-09

    Homopolymers or copolymers of acrylates, homopolymers or copolymers of norbornenes, and copolymers of acrylates with norbornenes, may be prepared by contacting acrylate and/or norbornene monomer reactant under polymerization conditions and in the presence of a solvent with a catalyst system consisting essentially of a Pd(II) dimer component having the formula: where L is a monodentate phosphorus or nitrogen ligand, X is an anionic group, and R is an alkyl or aryl group.

  2. Palladium (II) catalyized polymerization of norbornene and acrylates

    DOEpatents

    Sen, Ayusman; Kacker, Smita; Hennis, April; Polley, Jennifer D.

    2000-08-29

    Homopolymers or copolymers of acrylates, homopolymers or copolymers of norbornenes, and copolymers of acrylates with norbornenes, may be prepared by contacting acrylate and/or norbornene monomer reactant under polymerization conditions and in the presence of a solvent with a catalyst system consisting essentially of a Pd(II) dimer component having the formula: [(L)Pd(R)(X)].sub.2, where L is a monodentate phosphorus or nitrogen ligand, X is an anionic group, and R is an alkyl or aryl group.

  3. Synthesis of a liquid-crystalline resin monomer with the property of low shrinkage polymerization.

    PubMed

    Liu, Wenwen; Chen, Su; Liu, Yiran; Ma, Yuanping; Wang, Na; Zhang, Zhenting; Yang, Yuzhe

    2013-01-01

    To reduce the polymerization shrinkage of the dental resin composites, a new liquid-crystalline resin monomer was developed. The acrylate liquid crystalline resin monomer (ALCRM), (4-3-(acryloyloxy)-2-hydroxypropoxy) phenyl 4-(3-(acryloyloxy)-2-hydroxypropoxy) benzoate, was synthesized by a three-step method. Using the ALCRM as the main monomer, the degree of conversion (DC) and the volume shrinkage of the resin matrix were compared with the traditional composite resin monomer (Bis-GMA), 2,2-bis[4-(2-hydroxy-3-methacryloyloxy-propoxy)-phenyl] propane. The new monomer showed liquid crystalline characteristics with a mesomorphic phasetransition temperature between 18ºC and 42ºC. When copolymerized with triethylene glycol dimethacrylate (TEGDMA) at a weight ratio of 7:3, the DC of ALCRM was higher and the volume shrinkage was 3.62±0.26%, which was less than that of the Bis-GMA. The ALCRM exhibits promising potential for the development of superior dental resins with low volume shrinkage.

  4. FRACTURE RESISTANCE OF WEAKENED TEETH RESTORED WITH CONDENSABLE RESIN WITH AND WITHOUT CUSP COVERAGE

    PubMed Central

    Mondelli, Rafael Francisco Lia; Ishikiriama, Sérgio Kiyoshi; de Oliveira, Otávio; Mondelli, José

    2009-01-01

    Objectives: This in vitro study evaluated the fracture resistance of weakened human premolars (MOD cavity preparation and pulp chamber roof removal) restored with condensable resin composite with and without cusp coverage. Material and Methods: Thirty human maxillary premolars were divided into three groups: Group A (control), sound teeth; Group B, wide MOD cavities prepared and the pulp chamber roof removed and restored with resin composite without cusp coverage; Group C, same as Group B with 2.0 mm of buccal and palatal cusps reduced and restored with the same resin. The teeth were included in metal rings with self-curing acrylic resin, stored in water for 24 h and thereafter subjected to a compressive axial load in a universal testing machine at 0.5 mm/min. Results: The mean fracture resistance values ± standart deviation (kgf) were: group A: 151.40 ± 55.32, group B: 60.54 ± 12.61, group C: 141.90 ± 30.82. Statistically significant differences were found only between Group B and the other groups (p<0.05). The condensable resin restoration of weakened human premolars with cusp coverage significantly increased the fracture resistance of the teeth as compared to teeth restored without cusp coverage. Conclusion: The results showed that cusp coverage with condensable resin might be a safe option for restoring weakened endodontically treated teeth. PMID:19466244

  5. Severe Onychodystrophy due to Allergic Contact Dermatitis from Acrylic Nails

    PubMed Central

    Mattos Simoes Mendonca, Marcela; LaSenna, Charlotte; Tosti, Antonella

    2015-01-01

    Acrylic nails, including sculptured nails and the new ultraviolet-curable gel polish lacquers, have been associated with allergic contact dermatitis (ACD). We report 2 cases of ACD to acrylic nails with severe onychodystrophy and psoriasiform changes including onycholysis and subungual hyperkeratosis. In both cases, the patients did not realize the association between the use of acrylate-based manicures and nail changes. One patient had been previously misdiagnosed and treated unsuccessfully for nail psoriasis. The informed clinician should elicit a history of acrylic manicure in patients with these nail changes, especially in cases of suspected nail psoriasis refractory to treatment. Patch testing is a useful tool in confirming diagnosis. PMID:27170940

  6. Severe Onychodystrophy due to Allergic Contact Dermatitis from Acrylic Nails.

    PubMed

    Mattos Simoes Mendonca, Marcela; LaSenna, Charlotte; Tosti, Antonella

    2015-09-01

    Acrylic nails, including sculptured nails and the new ultraviolet-curable gel polish lacquers, have been associated with allergic contact dermatitis (ACD). We report 2 cases of ACD to acrylic nails with severe onychodystrophy and psoriasiform changes including onycholysis and subungual hyperkeratosis. In both cases, the patients did not realize the association between the use of acrylate-based manicures and nail changes. One patient had been previously misdiagnosed and treated unsuccessfully for nail psoriasis. The informed clinician should elicit a history of acrylic manicure in patients with these nail changes, especially in cases of suspected nail psoriasis refractory to treatment. Patch testing is a useful tool in confirming diagnosis. PMID:27170940

  7. Synthesis and characterization of SMC resins and nanocomposites from plant oils

    NASA Astrophysics Data System (ADS)

    Lu, Jue

    Sheet molding compounds (SMCs) are widely used in automotive parts, appliances, furniture, and construction. These materials heavily depend on the petroleum supply, which is depleting fast. The use of plant oils as alternative sources for SMC resins presents economic and environmental advantages over petroleum. Two synthetic methods have been used to develop new resins from triglycerides. The double bonds presented on the fatty acid chains are first converted to epoxy or hydroxyl functionality, the hydroxyl groups are maleinized, while the epoxies are acrylated and then further maleinized. These monomers, when combined with 33.3 wt % styrene, exhibit adequate thickening with MgO paste. The resulting polymers show storage moduli in the range of 1.9 to 2.5 GPa, and the glass transition temperatures range from 99 to 118°C. The cross-link densities show a linear increase with increasing number of functionality on the triglycerides. The prediction of cross-link density by the Miller and Macosko model matches the trend of experimental data, although it over predicts the cross-link density. The flexural strengths of these polymers vary in the range of 61--100 MPa, and flexural moduli are in the range of 1.90--2.79 GPa. The tensile strengths and moduli vary from 27 to 44 MPa and 1.6 to 2.5 GPa, respectively. The strengths of these polymers are following the prediction by vector percolation. The mechanical properties of these new polymers are comparable to those of commercial unsaturated polyesters. To further improve the physical and mechanical properties of these polymers, clay nanocomposites have been successfully synthesized by in situ polymerization. The morphology of nanocomposites can be described as a mix of intercalated and partially exfoliated sheets. The flexural modulus increases 30% at only 4 vol % clay content, but there is no significant effect on flexural strength, glass transition temperature and thermal stability. Property enhancement is related to the

  8. Resin impregnation process for producing a resin-fiber composite

    NASA Technical Reports Server (NTRS)

    Palmer, Raymond J. (Inventor); Moore, William E. (Inventor)

    1994-01-01

    Process for vacuum impregnation of a dry fiber reinforcement with a curable resin to produce a resin-fiber composite, by drawing a vacuum to permit flow of curable liquid resin into and through a fiber reinforcement to impregnate same and curing the resin-impregnated fiber reinforcement at a sufficient temperature and pressure to effect final curing. Both vacuum and positive pressure, e.g. autoclave pressure, are applied to the dry fiber reinforcement prior to application of heat and prior to any resin flow to compact the dry fiber reinforcement, and produce a resin-fiber composite of reduced weight, thickness and resin content, and improved mechanical properties. Preferably both a vacuum and positive pressure, e.g. autoclave pressure, are also applied during final curing.

  9. 4D printing smart biomedical scaffolds with novel soybean oil epoxidized acrylate

    PubMed Central

    Miao, Shida; Zhu, Wei; Castro, Nathan J.; Nowicki, Margaret; Zhou, Xuan; Cui, Haitao; Fisher, John P.; Zhang, Lijie Grace

    2016-01-01

    Photocurable, biocompatible liquid resins are highly desired for 3D stereolithography based bioprinting. Here we solidified a novel renewable soybean oil epoxidized acrylate, using a 3D laser printing technique, into smart and highly biocompatible scaffolds capable of supporting growth of multipotent human bone marrow mesenchymal stem cells (hMSCs). Porous scaffolds were readily fabricated by simply adjusting the printer infill density; superficial structures of the polymerized soybean oil epoxidized acrylate were significantly affected by laser frequency and printing speed. Shape memory tests confirmed that the scaffold fixed a temporary shape at −18 °C and fully recovered its original shape at human body temperature (37 °C), which indicated the great potential for 4D printing applications. Cytotoxicity analysis proved that the printed scaffolds had significant higher hMSC adhesion and proliferation than traditional polyethylene glycol diacrylate (PEGDA), and had no statistical difference from poly lactic acid (PLA) and polycaprolactone (PCL). This research is believed to significantly advance the development of biomedical scaffolds with renewable plant oils and advanced 3D fabrication techniques. PMID:27251982

  10. 4D printing smart biomedical scaffolds with novel soybean oil epoxidized acrylate.

    PubMed

    Miao, Shida; Zhu, Wei; Castro, Nathan J; Nowicki, Margaret; Zhou, Xuan; Cui, Haitao; Fisher, John P; Zhang, Lijie Grace

    2016-06-02

    Photocurable, biocompatible liquid resins are highly desired for 3D stereolithography based bioprinting. Here we solidified a novel renewable soybean oil epoxidized acrylate, using a 3D laser printing technique, into smart and highly biocompatible scaffolds capable of supporting growth of multipotent human bone marrow mesenchymal stem cells (hMSCs). Porous scaffolds were readily fabricated by simply adjusting the printer infill density; superficial structures of the polymerized soybean oil epoxidized acrylate were significantly affected by laser frequency and printing speed. Shape memory tests confirmed that the scaffold fixed a temporary shape at -18 °C and fully recovered its original shape at human body temperature (37 °C), which indicated the great potential for 4D printing applications. Cytotoxicity analysis proved that the printed scaffolds had significant higher hMSC adhesion and proliferation than traditional polyethylene glycol diacrylate (PEGDA), and had no statistical difference from poly lactic acid (PLA) and polycaprolactone (PCL). This research is believed to significantly advance the development of biomedical scaffolds with renewable plant oils and advanced 3D fabrication techniques.

  11. The Effect of Repeated Microwaving Disinfection on the Dimensional Stability of Acrylic Dentures

    PubMed Central

    Yannikakis, Stavros; Zissis, Alcibiades

    2014-01-01

    Objective The aim of this study was to evaluate the effect of repeated microwave disinfections on the dimensional stability of acrylic dentures. Materials and Methods Three groups of dentures made of a heat polymerized acrylic resin were tested. I: dentures kept in water (control group). II: dentures microwaved daily while being immersed into water (wet disinfection). III: dentures microwaved daily without being immersed into water (dry disinfection).
Measurements were taken across three reference points, on two occasions: after curing and immersion in water for 24 hours, and one week later.
Data obtained were analyzed using one-way analysis of variance (ANOVA) and Scheffe’s multiple range test. Results The results showed that the microwave disinfection provokes dimensional changes of the same pattern (shrinkage). The dentures which underwent wet disinfection exhibited the greatest shrinkage (p<0.05). Conclusions Disinfection using microwave energy may cause dimensional changes (shrinkage) of complete dentures.
The microwave “dry disinfection” method can be safely applied in everyday practice since the dimensional changes which occurred seem to be of no clinical significance.

  12. 4D printing smart biomedical scaffolds with novel soybean oil epoxidized acrylate.

    PubMed

    Miao, Shida; Zhu, Wei; Castro, Nathan J; Nowicki, Margaret; Zhou, Xuan; Cui, Haitao; Fisher, John P; Zhang, Lijie Grace

    2016-01-01

    Photocurable, biocompatible liquid resins are highly desired for 3D stereolithography based bioprinting. Here we solidified a novel renewable soybean oil epoxidized acrylate, using a 3D laser printing technique, into smart and highly biocompatible scaffolds capable of supporting growth of multipotent human bone marrow mesenchymal stem cells (hMSCs). Porous scaffolds were readily fabricated by simply adjusting the printer infill density; superficial structures of the polymerized soybean oil epoxidized acrylate were significantly affected by laser frequency and printing speed. Shape memory tests confirmed that the scaffold fixed a temporary shape at -18 °C and fully recovered its original shape at human body temperature (37 °C), which indicated the great potential for 4D printing applications. Cytotoxicity analysis proved that the printed scaffolds had significant higher hMSC adhesion and proliferation than traditional polyethylene glycol diacrylate (PEGDA), and had no statistical difference from poly lactic acid (PLA) and polycaprolactone (PCL). This research is believed to significantly advance the development of biomedical scaffolds with renewable plant oils and advanced 3D fabrication techniques. PMID:27251982

  13. Nontoxic Resins Advance Aerospace Manufacturing

    NASA Technical Reports Server (NTRS)

    2009-01-01

    The 2008 NASA Commercial Invention of the Year, PETI-330, is a polyimide matrix resin that performs well at high temperatures and is easily processed into composites in a simple, short curing cycle. Invented by scientists at Langley Research Center, PETI-330 is now licensed to Ube Industries, based in Japan with its American headquarters in New York. In addition to being durable and lightweight, the resin is also nontoxic, which makes it safe for workers to handle. PETI-330 was created specifically for heat-resistant composites formed with resin transfer molding and resin infusion, which formerly could only be used with low temperature resin systems.

  14. Zeta Potential Measurements of Glyoxalated Polyacrylamide (GPAM) Resins

    NASA Astrophysics Data System (ADS)

    Libi, Sumit; Shrestha, Apsana; Norwood, David; Boone, Steven

    2013-03-01

    We will describe the use of a NICOMP 380 ZLS light scattering instrument (Particle Sizing Systems) to measure the zeta potential of glyoxalated polyacrylamide (GPAM) resins used in the paper industry. These experiments are part of a broader study of GPAM molecule properties (molecular weight, RMS radius, contour and persistence length) intended to understand differences in performance between various GPAM resins (specifically, differences in drainage performance during paper processing and wet/dry strength of paper). Additionally, zeta potential measurements help to understand the long term stability of these resins. Data and results obtained from the experiment will be presented.

  15. 40 CFR 63.5734 - What standards must I meet for resin and gel coat application equipment cleaning operations?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-containing solvents used for removing cured resin or gel coat are exempt from the requirements of 40 CFR part... 40 Protection of Environment 12 2011-07-01 2009-07-01 true What standards must I meet for resin... Pollutants for Boat Manufacturing Standards for Resin and Gel Coat Application Equipment Cleaning...

  16. 40 CFR 63.5734 - What standards must I meet for resin and gel coat application equipment cleaning operations?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-containing solvents used for removing cured resin or gel coat are exempt from the requirements of 40 CFR part... 40 Protection of Environment 12 2010-07-01 2010-07-01 true What standards must I meet for resin... Pollutants for Boat Manufacturing Standards for Resin and Gel Coat Application Equipment Cleaning...

  17. Acrylic Finger Prosthesis: A Case Report

    PubMed Central

    Bandela, Vinod; M, Bharathi; S V, Giridhar Reddy

    2014-01-01

    Hands basic function is to grasp, hold and manipulate items. Hand gesture is perhaps the most blatant example of non-verbal communication. Finger and partial finger amputations are most frequently encountered forms of partial hand loss. Common causes are traumatic injuries, congenital absence or malformations present great clinical challenges. In addition to immediate loss of grasp strength, finger absence may cause marked psychological trauma. Individuals who desire finger replacement usually have high expectation for the appearance of prosthesis. This clinical report portrays simple method to retain acrylic finger prosthesis. PMID:25302271

  18. Adherence of Candida albicans to denture base acrylics and silicone-based resilient liner materials with different surface finishes.

    PubMed

    Nevzatoğlu, Erdem U; Ozcan, Mutlu; Kulak-Ozkan, Yasemin; Kadir, Tanju

    2007-09-01

    This study evaluated the surface roughness and Candida albicans adherence on denture base acrylic resins and silicone-based resilient liners with different surface finishes. Four commercial denture base acrylic resins (three heat polymerized and one room temperature polymerized) and five silicone-based liner materials (two heat polymerized and three room temperature polymerized) (10 x 10 x 2 mm) were tested in this study. The materials were processed against glass or plaster or finished with a tungsten carbide bur. Surface roughness measurements were made using a profilometer with an optical scanner probe. All specimens were ultrasonically cleaned in water for 15 s, autoclave sterilized, and contaminated with C. albicans solution for adherence assay evaluation. The materials processed against the glass surface showed significantly lower surface roughness values (0.11 +/- 0.1-1.66 +/- 1.1 microm) than those of the materials processed against the dental plaster (2.61 +/- 0.2-6.12 +/- 2.8 microm) or roughening with a bur (1.48 +/- 0.2-7.05 +/- 1.2 microm; p < 0.05, one- or two-way analysis of variance). Also, the materials processed against the glass surface showed lower C. albicans adhesion (mean ranks 120.36) than those of the materials processed against the dental plaster (mean ranks 139.77) or roughening with a bur (mean ranks 143.06), but the differences were not statistically significant (p > 0.05, Kruskal-Wallis and Mann-Whitney). In all types of surface finishes, C. albicans adhesion on denture base acrylics was significantly less (mean ranks 90.18-90.40) than those of silicone liners (mean ranks 119.38-205.18; p < 0.01, Kruskal-Wallis).

  19. 40 CFR 721.10500 - Acrylated mixed metal oxides (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Acrylated mixed metal oxides (generic... Specific Chemical Substances § 721.10500 Acrylated mixed metal oxides (generic). (a) Chemical substance and... mixed metal oxides (PMN P-06-341) is subject to reporting under this section for the significant...

  20. 40 CFR 721.10500 - Acrylated mixed metal oxides (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Acrylated mixed metal oxides (generic... Specific Chemical Substances § 721.10500 Acrylated mixed metal oxides (generic). (a) Chemical substance and... mixed metal oxides (PMN P-06-341) is subject to reporting under this section for the significant...