[A method for measuring apatite crystals in human dentine by high resolution transmission electron microscopy].

High resolution electron microscopy now makes it possible to use an original method for measuring biological apatite crystals. The crystals of intertubular sound dentine have an average width of 296 A (standard deviation: 37) and an average thickness of 32 A (standard deviation: 5). During the course of so-called arrested caries, crystals get twice as thick compared to those sound dentine, whereas their width remains unchanged.