Effectiveness of commonly available surface protecting agents in maintaining microhardness of two cements

To estimate the microhardness of glass ionomer cement (vitrofil) and resin modified glass ionomer cement (vitremere) in the presence and absence of different surface protections.

An in-vitro experimental study.

The Department of Operative Dentistry, Dr. Ishrat-ul-Ebad Khan Institute of Oral Health Sciences, Dow University of Health Sciences and the Department of Material Sciences, NED University, Karachi, from August 2011 to January 2012.

Seventy-two discs of each material were made in polytetrafluoroethylene mold which was 10 mm in diameter and 2 mm in thickness. Four groups were made for each material containing 18 discs; G1/G5 (control group), G2/G6 (solid petroleum jelly), G3/G7 vernal (resin varnish), G4/G8 (nail varnish). After initial setting reaction surface protection was applied to discs. Once the surface protection was dried, discs were stored in deionized water at 37°C for 24 hours. After 24 hours, the discs were polished. Microhardness test were performed in digital microhardness tester. The results were statistically analyzed with the help of two-way ANOVA.

For glass ionomer cement the only G4 (nail varnish) differed from the G1 (control group) [p < 0.05], No significant difference was seen with other surface protection agents. For resin modified glass ionomer cement, the G7 (resin varnish) and G8 (nail varnish) gave better result from the G5 (control group).

Nail varnish and resin varnish showed better surface protection for GIC and RMGIC. The presence of toluene in nail varnish have harmful effects so should not be preferred if resin varnish is available.