[Polarization-optical examinations of fissure contents (author's transl)]

The fissure contents of human premolars and molars were examined by a polarization-optical method, and the results obtained were compared with those achieved by light microscopy. A striking feature in this connection was the predominant isotropy of orange-colored fissure contents, which is not consistent with previous polarization-optical results obtained for the dental cuticle. Fissure contents usually showed smaller-area changes in color than did the dental enamels. Fissure contents transparent in thin ground sections were usually characterized by anisotropy. Polarization-optically, orange-colored contents of particularly narrow and deep fissures showed a different behavior than the whitishyellow, materia-alba-like superficial fissure contents, which suggests differences in crystallization structure.