A method of semi-quantitative microradiographic analysis of root surface lesion remineralization.

The purpose of this study was to present a modified photometer based digital analysis system for image enhanced microradiographic semi-quantitation of reactions of demineralization and remineralization of root surface lesions. The system was used to determine effects of fluoride on abraded root surface dentin in vitro. Lesions of 30-40 micron depth were produced during 18 h exposure of 180 micron thick single sections in solution of 3 mM Ca (Ca/P 1.67) and 30 mM lactic acid at pH 5.1. Mean mineral content of the lesions was 32% relative to adjacent sound dentin. Exposure of 20 h in the same acid with 5 mM Ca (Ca/P 1.67) and 0.12 mM NaF at pH 6.1 restored the mean mineral content to 76% of normal and increased the resistance of the lesions to demineralization. Remineralization and subsequent demineralization characteristics indicated the growth of fluorapatites on residual minerals in the dentin lesions. The microradiographic analysis system proved to be sensitive and critical in these studies.