The Microleakage And Fluoride-release Properties Of Dental Composite Resins With Fluorphlogopite/Fluorapatite Fillers

Objectives:To study the effect of different components and contents of porous fluorphlogopite/fluorapatite fillers on the microleakage and fluoride release from dental composite resins. To provide theoretical basis for further experiments and find the appropriate filler composition and ratio.Methods:Five groups of fluorphlogopite powders with different fluorapatite ratio was prepared by casting method, two-step heat treatment, defined as group F10、F9、F8、F6and F5with mass fraction of0%、10%、20%、40%and50%. All the five groups were etched with HF to get the porous structures filler powders. The filler powders were mixed with the composite resin respectively by mass fraction of60%,65%,70%, and then15test groups of composite resin were introduced. Taking the composite resin Filtektm P60(3M ESPE) which was used frequently in clinic and F8-60%dense fillers without etched as control groups, filling and dyeing the teeth with class V cavity. Observing the depth of dye penetrated under the microscope. Meanwhile, making the composite resin into standard tablets, soaking them in artificial saliva and detecting the fluoride concentration by ion selectivity electrode method. Calculating the amount of unit surface area fluoride release from the composite resin that accumulated in40days. Results:1. The microleakage of F5、F6、F8、F9、F10groups with different mass ratios has no significant difference (P>0.05); The microleakage of filler powders by mass fraction of60%,65%has no significant difference (P>0.05); While the mass fraction of filler powders was70%, the microleakage of F6-70%group is less than F9-70%group (P>0.05), Among other groups has no significant difference (P<0.05). The microleakage of porous fillers and dense fillers has no significant difference (P>0.05). The microleakage discrepancy between test groups and P60group has no significant difference (P>0.05).2. For group F5、F6、F8、F9, with the growth of filler content, the amount of unit surface area fluoride increases. Except for the comparisons of group F8-65%and group F8-70%, group F8-65%and group F8-60%have no statistical significance, the amout of unit surface area fluoride has significant difference in different filler content of other groups.With60%filler content, the comparison between group F8/F9and other groups has significant difference (P<0.05). For group F5, F6and F10, the comparison between each other has significant difference (P<0.05). The comparison between F8and F9has no significant difference.With65%filler content, the comparison between each of F5/F6/F8/F9/F10has statistic significance. With70%filler content, the comparison between group F10/F5and other groups has statistic significance; the comparison between each of group F6, F8and F9has statistic significance; the comparison between F10and F5has no statistic significance (P=0.054).The amount of fluoride releasing from F8-60%porous group is apparently higher than F8-60%dense group (P<0.05).Conclusion:1. Porous fillers has no significant influence on the microleakage of the fluorphlogopite/fluorapatite resin composites.2. The porous fluorphlogopite/fluorapatite resin composites has the better fluoride releasing function than the dense fillers, the fluoride amount has positive correlation with filler’s fraction.