Abstract
The supragingival dental calculi of the twenties of youth and the past forty of adult were compared concerning the change of structure and composition. The dental calculi were examined using a stereoscopy, a SEM, and the SEM-EDS. The granular crystals were observed in the calculi of youth. The calculi of adult showed a lamellar pattern. The granular, fibrous, and flake-like crystals were observed in the calculi of adult. SEM-EDS analysis showed that Ca and P were major elements, and Na and Mg were the trace elements. It was suggested that the difference may be cause in the content of Na and Mg related with aging. The Ca/P molar ratio was 1.19 on average in the youth. The Ca/P molar ratio was 1.46 on average in the adult. The possibility that the difference is in the crystal of dental calculus because of the aging was suggested.
