MR Micro-imaging Study of Water Migration into Glass Ionomer Dental Cements - the Efficiency of Surface Coating

Introduction Glass Ionomer Cements (GIC) are widely used dental materials. They adhere to hard dental tissues, release fluoride ions and are bio-compatible [ 11. GIC are obtained from the reaction during the hardening process between a polymeric acid and acid-degradable glass. Water plays a crucial role in this reaction; its absence retards or prevents the reaction while high concentrations results in improper glass matrix formation. In either case, the resulting cement has poor mechanical properties. A potential problem that may manifest itself in clinical applications is the migration of water from the oral cavity into the still hardening cement. To prevent this process, special surface coatings (varnishes) were proposed. Magnetic resonance micro-imaging is a convenient tool for studying water migration into dental cements and other porous materials because of its good spatial resolution and high sensitivity [2]. The aim of our MR micro-imaging study was to evaluate the effect of surface coating on the reduction of water contamination in glass GIC restorations.