Self-reparability of glass-ionomer cements: an in vitro investigation

Despite the advantages of glass-ionomer cement (GIC) restorative materials, they exhibit low mechanical properties and are susceptible to dissolution. The purpose of this study was to investigate the existence of self-reparability of a GIC material. Thirty Fuji IX discs were fabricated and subjected to desiccation. The discs were randomly separated into three groups: one group was kept in air, a second group was soaked in water, and a third group was placed in casein phosphoprotein-amorphous calcium phosphate-containing solution (Dentacal; NSI, Hornsby, Australia). After 21 d of incubation, all specimens were subjected to biaxial flexure testing. One-way ANOVA revealed a statistical difference in the biaxial flexure strength between the groups. Weibull statistics revealed that the Dentacal group demonstrated a lower probability of failure than the other groups. The air group exhibited the highest probability of failure. The difference between the specimens was expected as a result of enhanced cross-linking between the polyalkenoate chains and the GIC particles, and the diffusion of ionic components to the set GIC. Therefore, perhaps a form of reparative mechanism exists for precrazed GIC when it is exposed to a remineralizing solution. In addition to the benefit on natural tooth structures, this study indicates that remineralizing solutions are also beneficial for maintaining the mechanical integrity of GIC restorations.