L- and D-amino acids in the composition of dental bioapatite and the determination of human age

Abstract

The purpose of work is to determine the ratio of amino acid enantimers in bioapatite of human teeth and the influence of pathological processes in periodontium on the degree of racemization of amino acids. Objects of research - enamel without signs of caries, root dentin of permanent teeth and enamel of human carious milk teeth (n=16). Identification and determination of amino acid content in the samples was performed on a GC-17A gas chromatograph (Shimadzu, Chirasil-L-Val capillary column). D-forms were detected for three amino acids: alanine (Ala), aspartic (Asp) and glutamic (Glu) acids. Studies have shown the highest D/L Asp and Glu ratios for bioapatite enamel of tooth, removed due to pathological changes in periodontal tissues, and root dentin of the retained teeth. The ratio D/L Asp indicates the absence of relationship between the degree of racemization of aspartic acid in the teeth involved in pathological processes and biological age. Low D/L ratios of Asp, Glu and Ala are determined in teeth removed by orthodontic indications. It was noted that the use of racemization degree of aspartic acid in enamel and dentin bioapatite as one of the methods for assessing the exact biological age of unidentified remains is problematic without identifying inflammatory and degenerative processes in periodontal tissue.