FLUORIDE UPTAKE INTO HUMAN TEETH FROM A FLUORIDE-RELEASING THIN LAYER AFTER A LONG PERIOD OF FILLING

Abstract

Fluoride ( F ) distribution in human teeth was measured using an in-air micro-PIGE and micro-PIXE system. Class V cavities in the extracted teeth were prepared with Fluoro-Bond Shake One to provide a thin layer of an F-releasing material (FRM). The cavities were then filled with Beautifil Flow F10 (FRM, Group I) or LITE FIL IIP (non-FRM, Group II). Following a four-year period, specimens were cut longitudinally perpendicular to the cavity floor. The F distribution was measured at the floor of the cut surface. The position including 90% of the intact Ca level was defined as the wall surface. Based on this demarcation, indices of F distribution (surface F concentration and F penetration depth) were determined. Thickness of FRM thin layers varied (≈339 μm) and did not affect F distribution. Both values of F distribution indices in Group I [821–8763 (mean 3797) ppm, 34–668 (mean 241) μm] were significantly larger than those in Group II [0–7064 (mean 1865) ppm, 0–143 (mean 21) μm]. The F distribution in Group I was affected more by the filling material than by the FRM thin layer during the four-year exposure. Methodologies using this system may give insightful information for the development of new dental materials.