Fig. 2. Ultrastructural characteristics of the enamel interphase matrix layer.
a, appearance of organic enamel matrix at fracture surface prefixed for 6 days, etched in EDTA for 90 min, fixed in glutaraldehyde, post fixed in OsO4 and subjected to critical point drying.
b, higher magnification view of enamel organic matrix at fracture surface after specimen prefixation for 6 days, etching in phosphoric acid for 45 sec, fixing in glutaraldehyde, and critical point drying.
c, enamel hydroxyapatite crystals after etching in phosphoric acid for 45 sec, fixing in glutaraldehyde and drying (same magnification and same specimen as in 1B above).
d, collagen network of dentin (same magnification, processing, and specimen as in 1C above) (bar=500 nm).
Individual bars refer to microscopic scales for each image.
KEY: E, enamel; OM, organic matrix; D, dentin