Enamel Surface in "White-Spot" Formation

¹ Eastman Dental Dispensary, Rochester, New York

An investigation of the role of the enamel surface in "white-spot" formation was undertaken. Enamel surfaces of erupted and unerupted permanent teeth were abraded to remove the outer surface, and these surfaces, along with an adjacent unabraded area as controls, were exposed to a variety of demineralizing buffer solutions. The resulting lesions on the sectioned teeth were examined by microradiography and polarized-light microscopy. The "white-spot" lesion was found to occur both on abraded and on unabraded enamel of erupted and unerupted teeth. The finding on abraded enamel of a less decalcified surface layer over a more decalcified subsurface enamel, as seen with unabraded enamel, suggests that the difference in composition between surface and subsurface enamel is not determinant of "white-spot" formation but rather appears to influence only the duration of the "white spot." Of primary importance in "white-spot" formation is the composition of the demineralization environment, e.g., absence of complexing ions and, as shown previously,¹¹ the mechanics of the dissolution process (non-agitated systems).