title: Ion leaching of a glass-ionomer glass: an empirical model and effects on setting characteristics and strength.
abstract: The release of ions from a glass-ionomer glass, which in the polyacid matrix effects the cross-linking and setting of a cement, can be modelled and initiated by acid-treatment in a dilute acid. This study examined the effect of time of acetic acid leaching on the working time, setting time, and strength of a model GIC. A reactive fluoride glass was immersed in hot acetic acid for 0 (control), 5, 15, 35, 65, 95 and 125 min, filtered and dried. The glass was mixed with an experimental GI liquid in a capsule system and the mixed pastes assessed for working and initial setting time. Compressive strength testing was undertaken according to ISO9917:2003. Immersion time had a significant effect on both working and setting time of the resultant pastes only up to 65 min of immersion, and corresponded with a thin-film ion diffusion model. Compressive strength did not vary significantly with immersion time. The glass-ionomer setting reaction can be conveniently retarded by immersion of the powder in acetic acid, without affecting strength. A reactivity model was developed, whereby the effects of various changes to the leaching process may be usefully examined.
authors.affiliation: School of Dental Science, University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Leon H
authors.initials: LH
authors.lastname: Prentice
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Tyas
authors.forename: Michael F
authors.initials: MF
authors.lastname: Burrow
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D000180:Acrylic Resins / Q000737:chemistry*; D002214:Capsules; D019245:Compressive Strength; D007477:Ions; D008422:Materials Testing; D008956:Models, Chemical; D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D011208:Powders; D012822:Silicon Dioxide / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D002214:Capsules; D007477:Ions; D011208:Powders; D012996:Solutions; C015897:glass ionomer; D014867:Water; D012822:Silicon Dioxide; D019342:Acetic Acid