Remineralization of incipient caries studied by high-resolution electron microscopy

The present study presents a study on the remineralization of enamel incipient caries by HREM (high-resolution electron microscopy). The electron-transparent specimens (200-100 A) were prepared with argon ion thinning technique. The result showed some special crystallites, single or conglomerate (mostly on both sides of sheath), their shape, size and degree of electron-transparency indicated that they might be remineralized crystallites. They were distributed in the centre and edge of the carious lesions. Two patterns of remineralization had been observed. One was formation of new crystallites, and the remineralized crystal nuclear during development were found under HREM. The other was growth of the original crystals. The HREM images directly showed that the remineralized crystallites' chemical structure was mainly apatite, but its characteristics should be further studied.