Advanced Techniques of Micro-Analysis and Confocal Microscopy: Perspectives for Studying Chemical and Structural Changes at the Interface Between Restorative Materials and the Cavity Wall

Abstract

Migration of trace amounts of elements and structural changes characterize the interface between immiscible substances. The contact zone among filling materials, saliva, and the cavity wall has the additional function of preventing the progress of leakage and subsequent caries. Difficulties in chemically and structurally analyzing the gradients of composition in an interface of microscopic dimensions characterize the experimental situation. The use of advanced techniques of instrumental micro-analysis and techniques of micro-visualization is our approach to the problem. With confocal laser scanning microscopy (CLSM), effects of the components of the filling material on the structure of the cavity wall can be visualized non-destructively. Surface analysis with electron spectroscopy (XPS) and micro-spot analysis with laser mass analysis (LASMA) give the information on changes of the elemental composition of the cavity wall. The effects of the filling materials on the structure of enamel are correlated with the pre-treatment of the cavity wall. XPS and LASMA give evidence that fluoride does not migrate into the enamel of the cavity wall.