Comperative Evaluation of Fluor Releasing and Re-charge Properties, Surface Roughness and Bonding Values to Dentine of Different Restorative Materials Containing Glass Ionomer

The aim of this study is to determine the fluor releasing and uptaking capacity by comparing restorative materials containing glass fillers with different structures and convantional glass ionomer cement; to determine the effect of various pH levels on surface roughness of glass ionomer based restorative materials; and to compare bonding forces by applying the micro-tensile test method to these materials.Five different restorative materials containing glass ionomer were selected for the study. These materials are conventional glass ionomer cement, resin-modified glass ionomer cement, resin-modified glass ionomer cement with nano-fillers, giomer (pre-reacted glass ionomer) and polyacid-modified composit resin(compomer).In the study ion-specififc electrod (96-09BN) connected to ion-analysis machine (pH/ISE meter, model 710A) was used to determine the concentration of fluoride. Surface roughness was determined by using a profilometer (Surftest; Mitutoyo Corp, Tokyo, Japan) with a tip diameter of 5 µm. The universal test machine (Micro Tensile Tester T-61010K Bisco, US) was used for micro-tensile testing technique.In the study fluoride release of all materials was demonstrated at all test periods. Fluoride releasing values at first day were reported statistically significant in conventional GIC compared to other materials. Whereas on the other test days, the most fluoride releasing values were observed statistically significant in conventional GIC and RMGIC (p<0.05). Fluoride releasing of Giomer at overall the test periods was reported more than compomer. Subsequent to topical fluoride application an statistically significantly increased fluoride releasing of all materials was observed (p<0.05). It was reported that fluor uptake values were higher in the giomer group.The lowest roughness values was reported in RMGIC and it was followed by giomer, compomer, conventional GIC and RMGIC with nanofillers respectively.Giomer group had the greatest bonding values and was followed by compomer, resin-modified glass ionomers and conventional glass ionomer group respectively. Statistically significant adhesive failure was seen in giomer (p<0.05).