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Query: EC:2.3.1.177 (BIS)
 957 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

7 patients were occupationally sensitized to dental composite resin products (DCR): 6 dental nurses and 1 dentist. All had a positive patch test to their DCR. 2 independent types of allergy were seen; (a) aromatic epoxy acrylate, and/or (b) aliphatic acrylates. 4 out of 5 patients reacted to BIS-GMA, the most widely used aromatic epoxy acrylate in DCR, but not the dentist. She and 2 dental nurses were allergic to aliphatic acrylates, including triethylene glycol dimethacrylate (TREGDMA) and triethylene diglycol diacrylate (TREGDA). 4 patients were allergic to epoxy resin (ER) (containing mainly MW 340), possibly an impurity in some DCR. 2 patients were also allergic to methyl methacrylate (MMA): the dentist, had been exposed to MMA, but the nurse's exposure was uncertain. 1 patient was also allergic to rubber gloves, 2 to rubber chemicals but not their gloves, and 5 to disinfectants used. diagnosis was delayed as long as 13 years in spite of previous patch testing. Dermatologists need to use the patients' own DCR and the (meth)acrylate series for patch testing. No dental nurses could continue their occupation, but the dentist could occasionally handle DCR if wearing PVC gloves. Dental personnel need to know about the risks of DCR, and use no-touch techniques and protective gloves.
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PMID:Allergic contact dermatitis from dental composite resins due to aromatic epoxy acrylates and aliphatic acrylates. 252 51

The use of short glass fibers as a filler for dental restorations or cement resins have not been examined extensively. The mechanical properties and untreated glass fibers (5 microns dia x 25 microns) in Bis-phenol A glycidyl methacrylate (BIS-GMA) diluted with triethylene-glycol dimethacrylate (TEGDMA) resin were investigated for possible use as a restorative dental composite or bone cement. Compression, uniaxial tension and fracture toughness tests were conducted for each filler composite mixtures of 40, 50, 60 and 70%. Set time and maximum temperature of polymerization were determined. The results show that the elastic modulus, tensile strength and compressive strength are dependent on the percent of filler content. Elastic modulus and compressive yield (0.2%) strength of silane treated glass fibers filled composite increased from 2.26 to 4.59 GPa and 43.3 to 66.6 MPa, respectively, wtih increasing the filler content while the tensile strength decreased from 26.7 to 18.6 MPa. The elastic modulus of the untreated composite was less than that of the silane treated fiber composite. The tensile strength and compressive strengths were 20 to 50% lower than those of silane treated composites. The fracture toughness of the silane treated glass fiber additions were not significantly different from the untreated additions. The highest fracture toughness was obtained at 50% filler content with 1.65 MPa m.5. Set time increased from 3.5 to 7.7 minutes with increased filler content and peak temperature dropped from 68.3 to 34 degrees C. The results of this study indicate that the addition of silane coated glass fiber to BIS-GMA resin increased the elastic modulus, tensile and compressive strengths compared with non-treated fibers. The addition of either treated or non-treated fibers increased the set time of the material and decreased the maximum temperature.
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PMID:Mechanical properties of BIS-GMA resin short glass fiber composites. 253 Feb 34

A new resin dentin adhesive consisting of a primer (phosphonate dimethacrylate) and bonding agent (phosphonated BIS-GMA) was evaluated with bond strength tests, marginal microleakage studies, and SEM examination. The mean bond strength to dentin was 15.6 +/- 3.7 MPa. Microleakage studies found no marginal leakage at the enamel cavosurface margin and very minimal microleakage at the dentin/cementum margins. SEM examination showed that the primer was very effective in modifying the smear layer.
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PMID:Shear bond strength, microleakage and SEM study of the XR Bond adhesive system. 253 77

The adsorption of 4-methacryloxyethyl trimellitate anhydride (4-META) was studied from ethanol and dichloromethane onto synthetic hydroxyapatite (containing about 1.5 monolayers of physisorbed water) in order to study its role in restorative composite bonding to teeth. The adsorption isotherm of 4-META was S-shaped and reversible from ethanol, and followed the Langmuir plot at lower concentrations. The isotherm was irreversible from dichloromethane, and a constant amount of adsorbate was removed from the solutions above a certain concentration. The irreversibly adsorbed compound was completely removed by washing with ethanol. Therefore, the bonding between teeth and the restorative resin containing 4-META as a coupling agent is micromechanical and not chemical in nature. An analysis of isotherms showed that the benzene rings of the adsorbate molecules lie flat on the surface for both solvents. The molecules adsorbed from ethanol rotate about the solvent-modified (esterified) or unmodified carboxylic anhydride moieties with methacrylate hydrocarbon groups which are folded upward. However, the molecules adsorbed from dichloromethane remain fixed to the surface without rotation, and their methacryloxyethyl groups are folded over the rings. The diametral tensile strength of a BIS-GMA polymer with adsorbate-covered apatite was approximately equal to that of the composite filled with untreated apatite.
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PMID:Adsorption of 4-methacryloxyethyl trimellitate anhydride (4-META) on hydroxyapatite and its role in composite bonding. 264 29

A dental assistant developed sensitivity to dental restorative materials within 3 months of starting to use them. They contained the epoxy acrylate BIS-GMA, which is the most commonly used dimethacrylate monomer in dental composite restorations. She was positive to a patch test with BIS-GMA, which was the probable allergen, and epoxy resin, but this substance was not present in the materials used, as shown by high performance liquid chromatography. The patient was also allergic to the disinfectant Desimex i containing dodecyl diaminoethyl glycine.
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PMID:Occupational dermatitis due to an epoxy acrylate. 294 56

This study evaluated the tensile bond strength of Conclude luting composite to dentin under different environmental conditions with Scotchbond dental adhesive, the FNP system, and unfilled BIS-GMA resin used as bonding agents. Although the bonding systems reportedly yield high tensile bond values to enamel, large differences were observed in this study for bond values to dentin. Only the FNP bonding system produced consistently high tensile load values to dentin under the three environmental conditions tested.
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PMID:Bond strength of a luting composite to dentin with different bonding systems. 295 95

The effect of alcohols, bonding resins, or dentin adhesives on the adhesive bond between the layers of visible light-activated composites when used as lubricant for composite instruments was investigated. The results of this study indicated that alcohols are not compatible with certain BIS-GMA-based and UEDMA-based composite systems (Herculite and Heliomolar composites were used for this investigation). Use of ethanol as a lubricant caused pure adhesive failure and low bond strength in UEDMA-based composite (Heliomolar), indicating that the bond strength was less than the cohesive strength of the composite. A bonding resin of a similar brand (or the same system) used to lubricate the composite instrument did not affect the bond strength of the bonded composite specimens. In light of this study, a bonding resin of the same resin system as the composite may be the most suitable and reliable material to be used for lubricating the composite instrument.
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PMID:Effects of four lubricants used during incremental insertion of two types of visible light-activated composites. 297

In its present version, the Gluma system for bonding restorative resin to dentin involves the application of an enamel bonding agent prior to the composite resin. Conceivably, pretreating the dentin with solutions of amino acids, and incorporating camphorquinone and selected methacrylic monomers into the Gluma adhesive would nullify the need for the enamel bonding agent. A bond strength to dentin of 13.4 MPa was obtained in the control experiment. Using a solution of pyruvic acid and glycine as pretreatment, and an optimized adhesive mixture containing glutaraldehyde, HEMA, BIS-GMA, camphorquinone, and water, bond strengths to dentin of 14.5 MPa and to enamel of 23.3 MPa were obtained. Thus, the new Gluma bonding system gave acceptable bond strengths without the prior application of enamel bonding agents.
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PMID:Adhesion to dentin by means of Gluma resin. 314 33

The bond strengths between composite layers either cured to themselves or to other types (classes) of composites of similar or different brands were measured by using a direct tensile test (true tension). The diametral compression test for tension for each material tested was also conducted according to ADA specification No. 27. The values were used for comparison. 1. The interfacial bond strengths were generally found to be higher than the cohesive strengths of the weaker materials when cured to different types of composites or of the weak region in the specimen when composites were cured to themselves. 2. The cohesive tensile failure of the materials occurred at much lower stress levels than their corresponding diametral tensile strength (ranging from 1/4 to 1/3 of the diametral strength). 3. When two types of composites were bonded together the cohesive failure occurred consistently within the materials with lower diametral strength. Correlation was observed between the values of cohesive strength of material measured with true tension and the diametral test. 4. A urethane dimethacrylate microfilled composite bonded weakly to BIS-GMA composite, therefore, their combined use should be avoided. 5. Incremental placement produced a clinically acceptable bond strength because it exceeded or was at least comparable to the cohesive strength of the material.
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PMID:Interfacial bond strengths between layers of visible light-activated composites. 327 79

In the United States there is a new method for obtaining strong adhesive bonding between composite resins and both dentine and enamel. This experimental procedure has not reached commercial availability but several manufacturers are making preparations to supply it. The procedure comprises the sequential application of three compounds in solution. The first is an aqueous solution of ferric oxalate which conditions the dentine or enamel surface. The second is an acetone solution of a surface-active compound such as N-phenylglycine. After the acetone evaporates the excess compound is removed by the use of more solvent. The next step is the application of an acetone solution of a monomer that resembles the BIS-GMA used in composite resins but which has certain important differences. The short label for it is 'PMDM' because it is the reaction product of pyromellitic dianhydride and 2-hydroxyethylmethacrylate. When the volatile solvent quickly evaporates a thin layer of the PMDM remains on the treated dentine or enamel surface. Composite resins will then adhere strongly to these prepared surfaces, giving tensile adhesive bond strengths up to 14 MN/m2. Bond strengths of this magnitude have, on at least ten occasions, been sufficient to break pieces of dentine out of the surfaces of the extracted teeth during testing. The bond strengths to dentine obtained by this method in the laboratory are much higher than the strengths obtained with commercially available materials. The new technique is more complicated than those now in use. This creates a challenge to the dental manufacturers who must produce and supply these materials in a storage-stable form and who must provide directions that will lead to their proper use and the best results.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Bonding of restorative materials to dentine: the present status in the United States. 389 42


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