Fluorine-analysis of Cavity Walls in Glass-ionomer Restorations using PIGE/PIXE System

Objective: The purpose of this study was to determine fluorine (F) distribution in cavity wall of glass-ionomer restorations using the proton induced gamma-ray emission and proton induced X-ray emission or PIGE/PIXE system.

Method: Class V cavities in buccal surfaces of eight extracted human teeth were drilled and filled with four glass-ionomer cements; Fuji IX_GP FAST CAPULE (FF), Fuji IX_GP EXTRA (FE), RIVA S/C (RV), and Clinpro XT Varnish (CX). After storing in water for 1month, two longitudinal sections including materials were obtained from each tooth. F and calcium distribution of specimens were evaluated using PIGE/PIXE system and F uptake into enamel and dentin cavity walls from the material was analyzed (n=8). The margin of cavity wall was defined as the spot containing 90% of calcium concentration in intact tooth. For the comparison of F uptake, the average F concentration (ppm) in each specimen was calculated at area 200µm from the cavity margin. One-way ANOVA and Games-Howell test were used for analysis (p<0.05).

Result: F distribution in all specimens represented that highest F concentration was at area of cavity margin and decreased as distance increased from cavity margin. There was no significant difference in F concentration at area of cavity margin among the materials in enamel cavity, while the concentration in dentin cavity for FE and CX were significantly higher than that for FF and RV. For F uptake, there was no significant difference among materials in enamel cavity, although F uptake from FE and CX were higher than that from FF and RV.

Conclusions: Among materials used in current study, there were some differences in F uptake, which could possibly lead to obtaining differences in clinical performance. The data obtained using PIGE/PIXE system was useful to understand fluoride benefit for preventing caries by mean of fluoride-containing material.