Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:A7KAX9 (grit)
 1,275 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thermocycling is widely used in the evaluation of dentin bonding agents. The purpose of this study was to determine the effect of increasing thermocycling times on the shear bond strength of composite resin to dentin using a NTG-GMA/BPDM-type bonding agent. Fifty human molar teeth were ground flat on the buccal surface into dentin (600 grit). Ten specimens were prepared for each thermocycling group of 100, 500, 1000, 2000, and 4000 cycles. The adhesive agent was applied to the dentin according to the manufacturer's instructions. A cyclindrical-shaped matrix was used to form the composite resin that was light cured to the treated dentin surface for 60 seconds. Thermocycling was started after 24 hours of storage in deionized water at 37 degrees C. Shear bond strengths were determined with an Instron universal testing machine at a cross-head speed of 0.5 mm per minute. The bond strengths in megapascals (MPa) were : 100 cycles 18.1 (+/- 5.2) MPa, 500 cycles 19.4 (+/- 4.0)MPa, 1000 cycles 16.5 (+/- 2.9), 2000 cycles 14.6 (+/- 5.1), and 4000 cycles 19.9 (+/- 3.2)MPa. When this data was subjected to an ANOVA, no significant difference was found between the groups.
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PMID:Effect of thermocycling times on dentin bond strength. 129 92

Use of porcelain denture teeth may be desirable in many clinical situations, including implant-supported prostheses. However, lack of space because of frameworks often precludes the use of conventional retention by diatorics and pins. Adhesion of porcelain denture teeth to denture resin could also stiffen and possibly strengthen dentures and decrease stain ingress between porcelain teeth and resin denture bases. Unlike previous studies that investigated the bond between conventional feldspathic metal-ceramic porcelain and bis-GMA based composite resin, this study investigated adhesion of denture tooth porcelain to polymethyl methacrylate (PMMA). High-energy air abrasion, hydrofluoric acid etching, and the use of a general purpose bonding agent resulted in an improved bond strength of heat-cured denture PMMA bonded to denture tooth porcelain. Silane coating did not improve bond strengths, and conventional air abrasion was no more effective than polishing with 600-grit silicon carbide. Storage in water and artificial aging substantially decreased bond strengths. The strongest bond strengths were achieved by a high-energy-abrasion + etching + multi-purpose bonding-agent treatment, but a simpler etching + multiple-purpose bonding-agent treatment also produced reliable results. A laboratory technique was suggested. The role of surface treatment in the mechanism of adhesion was examined with scanning electron microscopy. High-energy abrasion produced a slightly more detailed initial topography than conventional air abrasion, but after etching, the high-energy topography became much more detailed. Surface topography alone did not account for all differences found.
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PMID:Adhesion of denture tooth porcelain to heat-polymerized denture resin. 747 77

In dentistry, adhesion promotion with 3-methacryloyloxypropyltrimethoxysilane is usually sufficient, but its hydrolytic stability is a continuous concern. The hydrolytic stability of an alternative, 3-isocyanatopropyltriethoxysilane, was compared with that of conventional 3-methacryloyloxypropyltrimethoxysilane. Two silanes, both in 0.1 and 1.0 vol-% in ethanol-water, were evaluated in the attachment of an experimental bis-phenol-A-diglycidyldimethacrylate (Bis-GMA) resin to grit-blasted (with two different systems) titanium. Silane hydrolysis was monitored by FTIR spectrometry. Bis-GMA resin was applied and photo-polymerized on titanium. The specimens were thermocycled (6000 cycles, 5-55 degrees C). Surface analysis was carried out with scanning electron microscopy. Statistical analysis (ANOVA) showed that the highest shear bond was achieved with 0.1% 3-isocyanatopropyltriethoxysilane (12.5 MPa) with silica-coating, and the lowest with 1.0% 3-methacryloyloxypropyltrimethoxysilane (3.4 MPa) with alumina-coating. The silane, its concentration, and the grit-blasting method significantly affected the shear bond strength (p < 0.05). SEM images indicated cohesive failure of bonding, and, in conclusion, 3-isocyanatopropyltriethoxysilane is a potential coupling agent.
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PMID:Isocyanato- and methacryloxysilanes promote Bis-GMA adhesion to titanium. 1579 Jul 44