Normal Enamel. I. Quantitative Polarized Light Study

¹ Medical Research Council, Dental Research Unit, Dental School, Bristol, England

The birefringence values recorded for enamel, an average of -0.0025, were in general agreement with those reported by other workers. The volume of spaces in "normal" enamel was approximately 0.2 per cent. The imbibition curves showed that approximately half the sections were imbibable and the remainder were nonimbibable. This variation of normal enamel behavior is in agreement with the opinions of other workers.

The imbibition of normal enamel could be interpreted as a type of molecular sieve behavior.

Ten sections are required for a representative sample of bicuspid enamel mounted in water. More than 14 sections are required to obtain representation of the same enamel when mounted in Thoulet's solution (n = 1.62) and quinoline (n = 1.62).