STUDIES OF THE COMPOSITION OF TEETH

VI. THE COMPOSITION OF SYRIAN HAMSTER ENAMEL AND DENTIN EXTRACTED WITH KOH-ETHYLENE GLYCOL

¹ Department of Dental Research, Walter Reed Army Institute of Research, Washington, D. C.

The nitrogen content, KOH-ethylene glycol extractable portions, and the principal inorganic elements in extracted tissue residues have been established for Syrian hamster enamel and dentin from incisors and molars of males and females. The data obtained for such tissues is compared with data obtained previously when subjecting enamel and dentin to 900° C. The protein content of the tissues, as established by nitrogen analysis, was usually less than the material removed by KOH-ethylene glycol extraction. Some calcium, phosphorus, and magnesium, particularly phosphorus, were removed during the extraction process together with the organic components. Neither the protein nor extractable fraction of the tissues was usually as great as that portion of the tissues removed at 900° C. The KOH-ethylene glycol extracted tissue residues contained more calcium and less phosphorus than similar tissue residues heated to a constant weight at 900° C. The calcium: phosphorus ratios of the ethylene glycol extracted tissues were generally higher than those of the heated tissues.