title: Characterization of a novel light-cured star-shape poly(acrylic acid)-composed glass-ionomer cement: fluoride release, water sorption, shrinkage, and hygroscopic expansion.
abstract: This study evaluated the fluoride release, water sorption, curing shrinkage, and hygroscopic expansion of a novel experimental light-cured glass-ionomer cement. The effects of glycidyl methacrylate (GM) grafting, polymer : water (P : W) and powder : liquid (P : L) ratios were investigated. Commercial Fuji II and Fuji II LC cements were used as controls for comparison. All the specimens were conditioned in deionized water at 37 degrees C before testing. The results demonstrated that the experimental cement showed lower burst and slower bulk fluoride release than Fuji II and Fuji II LC. The experimental cement absorbed more water than Fuji II and Fuji II LC as a result of its hydroxyl and carboxyl functional group content. The lower water-diffusion rate and reduced hygroscopic expansion of the experimental cement suggest that it had a highly crosslinked network. Both Fuji II and Fuji II LC exhibited much higher shrinkage values (2.8% and 4.7%) than the experimental cement (0.8%). It appears that this novel cement will be a clinically attractive dental restorative because not only has it shown superior mechanical strength, it has also demonstrated satisfactory physical properties.
authors.affiliation: Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhao
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Platt
authors.forename: Dong
authors.initials: D
authors.lastname: Xie
mesh_terms: D000042:Absorption; D000180:Acrylic Resins / Q000737:chemistry*; D000327:Adsorption; D002245:Carbon Dioxide / Q000737:chemistry; D002327:Cariostatic Agents / Q000737:chemistry*; D004058:Diffusion; D004852:Epoxy Compounds / Q000737:chemistry; D004853:Epoxy Resins / Q000737:chemistry; D005459:Fluorides / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D006878:Hydroxides / Q000737:chemistry; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008968:Molecular Conformation; D012117:Resins, Synthetic / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D014867:Water / Q000737:chemistry*; D017155:Wettability
chemical_list: D000180:Acrylic Resins; D002327:Cariostatic Agents; D004852:Epoxy Compounds; D004853:Epoxy Resins; D005609:Free Radicals; C079765:Fuji II LC cement; D005899:Glass Ionomer Cements; D006878:Hydroxides; D008689:Methacrylates; D012117:Resins, Synthetic; D014867:Water; C084541:Fuji glass-ionomer lining cement; D002245:Carbon Dioxide; C041069:carboxyl radical; C006903:carbopol 940; C031356:hydroxide ion; D005459:Fluorides; C007870:glycidyl methacrylate