Preventive measures and caries progression: an in vitro study on fissures and smooth surfaces of human molars

The aim of this study was to compare pit-and fissure sealants with fluoride treatments in their effectiveness to inhibit or reduce the progression of enamel lesions, particularly in the fissure region. The effects of fissure probing as used in diagnosis were compared with in the same protocol. Using a combination of image analysis of X-ray pictures of full crowns and a light microscopic evaluation of cross-sections provided information on the three dimensional spread of enamel demineralization. Pit-and-fissure sealants were superior in protecting enamel against progression of demineralization, as long as the walls of the fissures were well covered. The protection against demineralization offered by fluoride was mainly restricted to the smooth enamel surfaces; in fissures no protection could be measured. Surface defects of the enamel caused by probing or abrasion aided the progress of the lesion.