FLUORIDATED CARBONATOAPATITE IN THE INTERMEDIATE LAYER BETWEEN GLASS-IONOMER AND DENTIN

The intermediate layer between a glass ionomer restoration and dentin was examined morphologically by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). SEM showed strong bon ding between the dentin and glass ionomer and formation of an intermed iate layer between them. FTIR spectra of successive scrapings through the ionomer/dentin interface zone showed that the intermediate layer i s composed primarily of mineral fluoridated carbonatoapatite. The pres ence of this sparingly soluble mineral at the interface between the to oth and the restoration may provide high resistance to secondary carie s and may, thus, be of great clinical importance.