1970 Volume 12 Issue 1 Pages 1-5
In 1900, C.S. TOMES [1] in his observations on the fish teeth stated that in fish teeth the dentin is exposed from the enamel cap to the supporting bone and although it seems to be an easy task whether the dentin is covered with a thin layer of enamel or not, it is actually a very difficult one (Fig. 1). This dentin is called “Kragen” by SCHMIDT and KEIL [2] and “outer dentin” by ISOKAWA [3], one of the present authors.
The surface of this dentin is given by TOMES to be brittle and become dissolved by the presence of an acid. On the other hand, CARTER [4] stated that in the teeth of hake the surface of outer dentin lacks any indication of enamel.
The authors concerned themselves with historadiographic observations of certain fish teeth of this outer dentin in certain fish teeth so as to contribute toward an elucidation of the long-standing problem.
