A preliminary report on the effect of storage in water on the properties of commercial light-cured glass-ionomer cements

Abstract

Two commercially available light-curable glass-ionomer cements, Vitrebond and XR-Ionomer, have been studied and their compressive strengths measured following storage under wet and dry conditions for varying lengths of time up to 3 months. The strongest cements were those stored in air and allowed to age. On the other hand, cements that were stored in water were found to become progressively weaker with time. Their failure mode was different from that of cements stored in air in that specimens became barrel-shaped as they were loaded and exhibited considerable plastic deformation prior to fracturing. By contrast, air-stored specimens behaved as predominantly brittle materials, the specimens essentially maintaining their integrity up to the point of catastrophic failure. Both of these findings indicate that the properties of these particular light-cured cements change markedly on exposure to moisture, a fact which is of clinical significance.

Effectiveness of surface protection for glass-ionomer, resin-modified glass-ionomer and polyacid-modified composite resins

“…While some studies have reported negative effects on physical properties as a result of water storage and subsequent sorption 17,[19][20][21][22][23][24][25][26] , Mitra 10) has found no significant differences in properties immediately after curing and extended storage in water. In our study, the hydration properties of conventional glass-ionomer cement and its hybrid versions were also investigated.…”

“…These results were consistent with those of the present study. It is noteworthy that both water uptake and water loss of restorative materials can compromise the physical properties of restorations 17,[19][20][21][22][23][24] . If water is lost due to desiccation, the reactions may stop and surface crazing may occur 19) .…”

Effect of Water on Shear Strength of Glass Ionomer Cements for Luting

“…This could be attributed to an increase in the rigidity of the cement matrix, whereby water molecules were discharged from the cement structure. Similarly, Nicholson et al and Saygili et al reported an increase in the compressive strength of conventional glass ionomer cements under dry condition 22,23) . The compressive strength of cylindrical specimens is known to be related to the sum of shear and tensile stresses raised in the specimen body under a compressive load 24,25) .…”

Surface hardness of hybrid ionomer cement after immersion in antiseptic solution

“…Metal ion which was detached from hydroxyl compound inside hybrid ionomer cement will cause the material to be fragile. 10 hybrid ionomer cement will absorb the liquid which will dissolve matrix forming cation and anion to surrounding areas. This happening will produce fragile cement dissolved easily, causing transparent significant alteration.…”