Quantitative Polarized-Light Microscopy of Sound Surface Enamel
B. HOUWINK 1
1 Organization for Health Research TNO, Laboratory of Microbiology, University of Utrecht, The Netherlands
Sections of sound enamel were studied with a polarized-light microscope. Measurements were taken in the outer zone, 90 micrometers (am) wide. Significant differences in retardation were observed even between closely situated points. Three differently composed layers were seen: an outer 5-imwide layer containing occasionally large spaces but frequently many small pores; next, an approximately 10-wn-wide layer with many small spaces; and finally, a layer with few and mainly small spaces.
Submitted on March 26, 1969
