Suthamma Khakhlong. The acid resistant layer and fluoride content in dentin after restoration with various fluoride releasing materials . Master's Degree(Operative Dentistry). Mahidol University. : Mahidol University, 2006.
The acid resistant layer and fluoride content in dentin after restoration with various fluoride releasing materials
Abstract:
The objectives of this study were to compare the thickness of the acid resistant
layer and quantity of fluoride in dentin after restoration with fluoride releasing
materials.
Twenty five caries-free human premolars were prepared for class I occlusal
cavities. The teeth were randomly divided into five experimental groups of 5 teeth
each, using five different restorative materials, a resin composite, a conventional glass
ionomer cement, a resin-modified glass ionomer cement, a compomer, and a giomer.
The specimens were analyzed for fluoride content after 1 week, 1 month, and 3
months at 10, 20, 30, 40, and 50μm beneath the restoration/dentin interface using EDS
attached to the SEM. Then the slices were demineralized in demineralizing solution
and sodium hypochlorite solution to observe the thickness of acid resistant layers in
dentin using an SEM at 3500x magnification.
The results of fluoride content measurement revealed that within the distance
of 50 μm beneath the restoration/dentin interface, there were no statistically significant
differences at 10, 20, 30, 40, and 50 μm at all evaluation times for each restorative
material. Within the material at 1 week, 1 month, and 3 months, there were no
statistically significant changes in resin composite, compomer, and giomer, whereas
there was a significant increase of fluoride contents in conventional and Resinmodified
glass ionomer cement. The comparison of different materials at the same
storage times exhibited that conventional and resin-modified glass ionomer cement
produced fluoride contents in dentin greater than other materials.
The results of acid resistant layers observation showed that all selected fluoride
releasing materials can create acid resistant layers. The thickness of these layers were
not statistically significantly different.