Comparative evaluation of surface microhardness and microleakage after application of commercially available G-Coat Plus, nano silver fluoride resin coat and petroleum jelly over glass ionomer cement restoration: an in vitro study

Abstract

Background Glass ionomer cement (GIC) is a widely used tooth coloured material. However, GIC holds certain undesirable properties. In order to overcoming the major drawback of moisture sensitivity, surface coatings like petroleum jelly, varnish are applied over GIC restoration. Thus, the present study was planned to compare efficacy of newly formulated nano silver fluoride resin coat with G Coat Plus and petroleum jelly on microhardness and microleakage of Type IX GIC. Methods Class V cavities were prepared on the buccal surface of thirty-six non carious premolars and restored with type IX GIC. The restored teeth were divided into 3 groups: Petroleum gel, G Coat plus and Nano silver fluoride resin coat. Protective surface coatings were applied over the restorations, dried for 2 minutes and thermocycled. Teeth were then placed in 1% methylene blue for 24 hours. Longitudinally sections were prepared and were observed under stereomicroscope at 25x magnification for dye penetration. Forty-five blocks of PVC were prepared and restored with GIC. Samples were divided into three groups equally as mentioned earlier and a layer of each coating was applied on all samples according to the groups and dried for 2 minutes. Further, surface microhardness (SMH) of the samples was tested by Vickers microhardness machine under a load of 50 grams for 10 seconds at 3 sites and a mean was calculated. Statistical analysis was conducted using post hoc and one way-ANOVA tests. Results The microleakage scores of three groups were statistically insignificant. The mean microhardness of all samples in the three groups showed no statistically significant difference. The mean surface microhardness of group 1 was 66.44±4.57 whereas for group 2 and group 3 it was 76.15±3.02 and 79.22±4.03 respectively. Conclusions The novel agent containing nano silver fluoride is showed superior results and is intended to augment the properties of GIC.