[In vivo study of remineralization with trace elements by laser scanning confocal microscope]

To evaluate in vivo the remineralization containing trace elements.

The volunteers were selected by pre-designed criteria of adopting and eliminating. Caries-like lesions were prepared in the enamel of extracted human premolars with the use of demineralizing solution. Sections of the normal and lesion enamel (approximately 2 mm x 2 mm) were prepared, with the cut surfaces protected by nail varnish. 2 enamel specimens were mounted in a removable appliance. By measuring lesion parameters (area, total and average dye fluorescence) on a tooth with confocal laser scanning microscopy (CLSM), the effect of remineralization was assessed. Specimens were cut and stained with a fluorescent dye (0.1 mmol/L rhodamine B) for 1 h and analyzed using CLSM.

CLSM detected significantly greater remineralization (P < 0.05) in the specimens treated with the trace elements fluoride-containing solution and only containing fluoride (P < 0.05), especially more obvious difference was shown upon remineralized solution with trace elements, which means it produced a greater remineralization. CLSM data of remineralized solution with trace elements were showed: delta Z vs. Area = -50.4 +/- 8.1; delta Z vs. TF = -27.8 +/- 3.8; delta Z vs. AF = -91.5 +/- 8.9.

The ability of remineralization of the new solution is better than that only containing fluoride in in vivo study. It can potentially prevent initiation of caries. This study provides not only the theoretical foundation for clinical application, but also shows a new kind of experimental method in the study of demineralization and remineralization.