A Scanning Electron Microscopic Study of Progressive Stages of Enamel Caries in vivo

Abstract

The present study was carried out to describe surface changes in the scanning electron microscope as related to different periods of carious dissolution in vivo. To ensure accumulation of microbial plaque, orthodontic bands with a standardized buccal space were placed for periods of 1, 2, 3 and 4 weeks on permanent premolars prior to extraction. Examinations in polarized light disclosed a gradual development of a subsurface lesion over time. In the SEM direct dissolution of the surface itself was a prominent feature at all stages of lesion development causing a universal enlargement of intercrystalline spaces. Results indicate that enlarged intercrystalline pathways provide the most important routes for the transport of minerals out of the enamel. The relative protection offered to the outermost crystals at any stage of lesion formation may be an indication of inhibitors acting at the plaque/enamel interface and/or calcium and phosphate present in the plaque.