In vitro evaluation of effectiveness of three different fluoride-releasing restorative materials on initial enamel caries

In this in vitro study, the protective effects of restorative materials with known flouride content, RMGIC (resin-modified glass ionomer sement) giomer, and glass carbomer which is recently put on the market on artificial initial caries lesions in simulated highly cariogenic oral environment were evaluated. Considering announced re-charge capabilities of these flouride containing restorative materials, flouridated toothpaste applicated in some groups and anti-demineralising effect also evaluated. 60 sound permanent molar teeth used in the study. These teeth were cut in mesiodistal direction using diamond saw blade wtih watercooling. Rectangular prisms of 5mm-5mm-2mm were prepared using buccal and lingual segments. These obtained 120 specimens were embedded in acrilic blocks. 60 specimens were used for microhardness analysis, and rest used for SEM-EDX analysis (Scanning Electron Microscopy with X-ray Microanalysis). Artificial initial caries lesions were created using demineralising solutions and then enamel blocks were exposed to in vitro pH cycling system simulating highly cariogenic oral environment. Just before pH cycling exposure the three main groups were each divided in two subgroups one with no additional application and the other with fluoridaded toothpaste application. Microhardness and mineral analyses were performed on enamel surrounding restorative materials at three different times during the experiment, first at the beginning of the experiment, then after creation of artificial early caries lesions and finally after pH cycling. Microhardness and SEM-EDX analyses showed results that were in concordance mostly. During pH cycle model fluoridated toothpaste added groups of RMGIC and glass carbomer were significantly better in anti-demineralising effect in comparision to other groups. Both giomer groups represented lower datas so it may be stated that giomer has lower anti-demineralising effect in comparision to the other restorative materials.