ABSTRACT
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
ABSTRACT
To examine the effect of apple and orange juices on the surface h ardness of direct tooth-colored restorative materials. The materials included resin-modified glass ionomer cement [Vitremer 3M[tm] ESPE[tm] Core buildup restorative] and composite resin [Filtek[tm] 3M[tm] ESPE[tm] Z350]. A total of 45 disks of each restorative material were prepared. The disks were divided into groups of 15, which were immersed for 7 days in deionized water [G1/G4, control group], apple juice [G2/G5], or orange juice [G3/G6]. The pH of the apple juice was approximately 4.8 and the pH of the orange juice was approximately 4.9. Surface hardness tests were performed before immersion and at various times following immersion. Statistical analysis included two-way ANOVA with repeated measurement and Tukey's test. Exposure to juices significantly reduced the hardness of both materials [p < 0.05], while deionized water did not affect the surface hardness of either material. The ionomer cement experienced a greater reduction than the composite resin [p = 0.000]. There was no significant difference in the effect of apple and orange juices. Juice box-type fruit juices reduced the hardness of direct tooth-colored restorative materials. Material selection should be considered when planning restorations in patients who have experienced tooth surface loss. In terms of the materials evaluated in this study, the composite material provides greater durability under acidic conditions