Cementum structure in Beluga whale teeth

• Published in: Acta biomaterialia Vol. 48; no. C
• Main Authors: Stock, S. R., Finney, L. A., Telser, A., Maxey, E., Vogt, S., Okasinski, J. S.
• Format: Journal Article
• Language: English
• Published: United States Acta Materialia, Inc 09-11-2016
• Subjects: BASIC BIOLOGICAL SCIENCES; Ca; cementum; dentin; growth layer groups (GLGs); MATERIALS SCIENCE; odontocete; synchrotron radiation; x-ray diffraction; x-ray fluorescence; Zn
• ISSN: 1742-7061; 1878-7568

We report that a large fraction of the volume of Beluga whale (Delphinapterus leucas) teeth consists of cementum, a mineralized tissue which grows throughout the life of the animal and to which the periodontal ligaments attach. Annular growth bands or growth layer groups (GLGs) form within Beluga cementum, and this study investigates GLG structure using X-ray fluorescence mapping and X-ray diffraction mapping with microbeams of synchrotron radiation. The Ca and Zn fluorescent intensities and carbonated hydroxyapatite (cAp) diffracted intensities rise and fall together and match the light-dark bands visible in transmitted light micrographs. Within the bands of maximum Ca and Zn intensity, the ratio of Zn to Ca is slightly higher than in the minima bands. Further, the GLG cAp, Ca and Zn modulation is preserved throughout the cementum for durations >25 year.