Effect of G-Coat Plus on the mechanical properties of glass-ionomer cements

Abstract

Background: Although various mechanical properties of tooth-coloured materials have been described, little data have been published on the effect of ageing and G-Coat Plus on the hardness and strength of the glass-ionomer cements (GICs). Methods: Specimens were prepared from one polyacid-modified resin composite (PAMRC; Freedom, SDI), one resinmodified glass-ionomer cement; (RM-GIC; Fuji II LC, GC), and one conventional glass-ionomer cement; (GIC; Fuji IX, GC). GIC and RM-GIC were tested both with and without applying G-Coat Plus (GC). Specimens were conditioned in 37°C distilled water for either 24 hours, four and eight weeks. Half the specimens were subjected to a shear punch test using a universal testing machine; the remaining half was subjected to Vickers Hardness test. Results: Data analysis showed that the hardness and shear punch values were material dependent. The hardness and shear punch of the PAMRC was the highest and GIC the lowest. Applying the G-Coat Plus was associated with a significant decrease in the hardness of the materials but increase in the shear punch strength after four and eight weeks. Conclusions: The mechanical properties of the restorative materials were affected by applying G-Coat Plus and distilled water immersion over time. The PAMRC was significantly stronger and harder than the RM-GIC or GIC.

Effect of a self‐adhesive coating on the load‐bearing capacity of tooth‐coloured restorative materials

“…6,7,[14][15][16][17][18][19][20] Knowledge of the mechanical properties of a material, with regard to its surface protection using a self-adhesive coating agent, can elucidate its behavior and, therefore, determine its clinical uses and performance. Hence, in the present laboratory study the aim was to compare flexural strength and hardness of seven aesthetic restorative materials, asses the effect of storage in distilled deionized water (DDW) for up to six months, and determine the effect of resin surface coating on the mechanical properties of the materials.…”

“…7 The hardness of the surface of restorative material is confounded by the presence and variable thickness of the layer of GCP present on its surface (Figure 1). The GCP is generally softer than the subsurface restorative material and it will result in an average hardness value indicative of the presence and thickness of the GCP layer and the depth of penetration of the indenter into the subsurface restorative material.…”

“…5 The self-adhesive coating bonds to GIC and provides a lamination effect that has been reported to increase the fracture toughness and shear punch strength of GICs, but decrease the surface hardness of the material. 6,7 The effect of storage in water for extended periods of one or more months on aesthetic restorative materials varies. Some studies have shown slight to substantial decreases in the elastic modulus and tensile strength of resin composites.…”

Recent Approaches In Restorative Glass Ionomer Cements

“…57,58 Rezin içerikli yüzey örtücü uygulaması cam iyonomer simanların mikrosertliğini arttırmadığı, hatta azalttığı ve yüzey pürüzlülüğünün de örtücü uygulanmış ve uygulanmamış restoratif cam iyonomer simanlar için benzer olduğu görülmüştür. 59,60 Buna karşın, nano dolduruculu yüzey örtücü uygulanan yüksek viskoziteli cam iyonomer simanların makaslama ve basma dayanımının dört ila sekiz haftalık süre sonunda arttığı bildirilmiştir. 60 Düşük yüzey gerilimine bağlı olarak kenar örtülenmesini de olumlu yönde etkilediği belirtilmiştir.…”

“…59,60 Buna karşın, nano dolduruculu yüzey örtücü uygulanan yüksek viskoziteli cam iyonomer simanların makaslama ve basma dayanımının dört ila sekiz haftalık süre sonunda arttığı bildirilmiştir. 60 Düşük yüzey gerilimine bağlı olarak kenar örtülenmesini de olumlu yönde etkilediği belirtilmiştir. 59 Nano dolduruculu yüzey örtücülerin, restorasyonun uygulandığı kişinin çiğneme kuvvetine, okluzyonuna, çiğneme alışkanlıklarına ve diyetine bağlı olarak ortalama altı ay süreyle restorasyon yüzeyinde kaldığı görülmüştür.…”