The use of the D-, L- aspartic ratio in decalcified collagen from human dentin as an estimator of human age

Among the methods dealing with the age estimation, the evaluation of the ra tio of the D-, L- form of the aspartic acid in tissues with a low metabolic turnover is considered to be the most precise. We introduced demineralizat ion of the dentin with 0.5 M EDTA adjusted to pH = 7.4. The advantage of su ch a procedure is that after demineralization we obtained pure insoluble pr otein (collagen) and soluble noncollagenous proteins in one step. In this s tudy we analyzed insoluble collagen. The amino acids obtained after the hyd rolysis were derivatized into TFA isopropyl esters and analyzed by gas chro matography on Chirasil L-Val capillary column. We analyzed human dentin fro m the lower canines. The correlation coefficient was 0.93 for our set of 71 persons. The result concurred with those of other scientists.