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High elastic modulus nanopowder reinforced resin composites for dental applications

dc.contributor.advisorLloyd, Isabel K.en_US
dc.contributor.advisorGreer, Sandra C.en_US
dc.contributor.authorWang, Yijunen_US
dc.date.accessioned2007-09-28T15:03:33Z
dc.date.available2007-09-28T15:03:33Z
dc.date.issued2007-08-27en_US
dc.identifier.urihttp://hdl.handle.net/1903/7406
dc.description.abstractDental restorations account for more than $3 billion dollars a year on the market. Among them, all-ceramic dental crowns draw more and more attention and their popularity has risen because of their superior aesthetics and biocompatibility. However, their relatively high failure rate and labor-intensive fabrication procedure still limit their application. In this thesis, a new family of high elastic modulus nanopowder reinforced resin composites and their mechanical properties are studied. Materials with higher elastic modulus, such as alumina and diamond, are used to replace the routine filler material, silica, in dental resin composites to achieve the desired properties. This class of composites is developed to serve (1) as a high stiffness support to all-ceramic crowns and (2) as a means of joining independently fabricated crown core and veneer layers. Most of the work focuses on nano-sized Al2O3 (average particle size 47 nm) reinforcement in a polymeric matrix with 50:50 Bisphenol A glycidyl methacrylate (Bis-GMA): triethylene glycol dimethacrylate (TEGDMA) monomers. Surfactants, silanizing agents and primers are examined to obtain higher filler levels and enhance the bonding between filler and matrix. Silane agents work best. The elastic modulus of a 57.5 vol% alumina/resin composite is 31.5 GPa compared to current commercial resin composites with elastic modulus <15 GPa. Chemical additives can also effectively raise the hardness to as much as 1.34 GPa. Besides>alumina, diamond/resin composites are studied. An elastic modulus of about 45 GPa is obtained for a 57 vol% diamond/resin composite. Our results indicate that with a generally monodispersed nano-sized high modulus filler, relatively high elastic modulus resin-based composite cements are possible. Time-dependent behavior of our resin composites is also investigated. This is valuable for understanding the behavior of our material and possible fatigue testing in the future. Our results indicate that with effective coupling agents and higher filler loading, viscous flow can be greatly decreased due to the attenuation of mobility of polymer chains. Complementary studies indicate that our resin composites are promising for the proposed applications as a stiff support to all-ceramic crowns.en_US
dc.format.extent4687139 bytes
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.titleHigh elastic modulus nanopowder reinforced resin composites for dental applicationsen_US
dc.typeDissertationen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.contributor.departmentMaterial Science and Engineeringen_US
dc.subject.pqcontrolledEngineering, Materials Scienceen_US
dc.subject.pqcontrolledHealth Sciences, Dentistryen_US
dc.subject.pqcontrolledEngineering, Materials Scienceen_US
dc.subject.pquncontrolledaluminaen_US
dc.subject.pquncontrollednanocompositeen_US
dc.subject.pquncontrollednanoindentationen_US
dc.subject.pquncontrolleddental crownen_US
dc.subject.pquncontrolledelastic modulusen_US


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