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Cross-Section Through Crown of Tooth
This is a cross-section through the crown of a tooth. Lines of Retzius (A) appear like growth rings in a tree stump. Enamel is harder toward the free surface than toward the D-E junction. Enamel hardness depends on: the degree of mineral-ization, the orientation of the enamel rods, the orientation of the crystallites within the rods, and the distribution of metallic ions which occur in trace amounts. Hardness at the enamel surface may be in-creased by the presence of fluoride ions.
Legend
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A - lines of Retzius |
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Lecture Notes
