title: Effect of immersion in water on linear expansion and strength of three base/liner materials.
abstract: The purpose of this study was to characterize three base/liner materials in the initial stage of setting, i.e., dual-cured (light-activated glass ionomer), light-cured (light-activated glass ionomer analogue), and chemically-cured (conventional glass ionomer) materials. Changes in dimension, weight and flexural strength were examined from immediately after setting to the end of one week following immersion in water. The results obtained from these three types of material differed from each other, and showed a statistically significant correlation between changes in dimension and weight. This may be attributed to hygroscopic expansion. They also showed different flexural strength, indicating differences in the polymerization system. From these results, it appeared that marginal gaps following setting would be compensated for by hygroscopic expansion during immersion in water for one day or more. Physical properties would be favourably improved following the setting process which continues to advance during immersion in water.
authors.affiliation: Department of Dental Materials, Okayama University Dental School, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Irie
authors.forename: H
authors.initials: H
authors.lastname: Nakai
mesh_terms: D000042:Absorption; D000704:Analysis of Variance; D003736:Dental Cavity Lining; D003793:Dental Restoration, Permanent / Q000379:methods; D005899:Glass Ionomer Cements / Q000737:chemistry*; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D010347:Patient Care Planning; D018583:Pliability; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: C091837:GC dentin cement; D005899:Glass Ionomer Cements; C091836:Ionosit; D008689:Methacrylates; D014867:Water; C074319:GC Lining Cement; C067790:Vitrabond; C084541:Fuji glass-ionomer lining cement; C005044:hydroxyethyl methacrylate