Crystal Structure Studies of Human Dental Apatite as a Function of Age

TL;DR

This study investigates how the crystal structure and carbonate content of human dental apatite change with age, revealing decreased crystallinity and increased carbonate substitution in teeth from ages 5 to 87 years.

Contribution

It provides detailed analysis of age-related structural and compositional changes in human dental apatite using multiple spectroscopic and diffraction techniques.

Findings

Crystallinity decreases with age.

Carbonate content increases with age.

A-type and B-type carbonate substitutions are present.

Abstract

Studies of the average crystal structure properties of human dental apatite as a function of the tooth-age in the range of 5-87 years are reported. The crystallinity of the dental hydroxyapatite decreases with the tooth-age. The a-lattice constant that is associated with the carbonate content in carbonate apatite decreases with the tooth-age in a systematic way, whereas the c-lattice constant does not change significantly. Thermogravimetric measurements demonstrate an increase of the carbonate content with the tooth-age. FTIR spectroscopy reveals both, B and A-type carbonate substitutions with the B-type greater than the A-type substitution by a factor up to ~5. An increase of the carbonate content as a function of the tooth-age can be deduced from the ratio of the v2 CO3 to the v1 PO4 IR modes.