Journal of the Japanese Association of Regenerative Dentistry
J Jpn Assoc Regenerative Dent Vol.8(1) pp.10-18
ISSN 1348-9615


Changes of composition in the subgingival calculus by aging

Hiroyuki MISHIMA1, Saori MIYAMOTO2, Kazuo TANAKA3, Atsushi OOKUBO4, Yasuo MIAKE5, Akiyasu NISHINO6
1Department of Early Childhood Education and Care, Kochi Gakuen College, Kochi, Japan
2Shimazu Hospital, Kochi, Japan, 3Tanaka Dental Clinic, Shimanto, Japan
4Department of Histology, Cytology and Development,
Nihon University School of Dentistry at Matsudo, Matsudo, Japan,
Hiu Dental Academy, Sasebo, Japan
5Department of Ultrastructural Science, Oral Health Science Center,
Tokyo Dental Collge, Chiba, Japan
6Department of Medical Hygiene, Kochi Gakuen College, Kochi, Japan

The subgingival dental calculi of people in their twenties and that of people over forty were compared to examine changes in structure and composition. The calculus samples of the older group were green, gray, and dark brown in contrast to that of the younger group. On the calculi of the older group, polygonal structures, flake-like structures, and bacillus-like structures were common. In the calculi of the younger group, small spherical structures were commonly observed. EPMA analysis revealed the composition of the calculi of the younger group contained higher levels of Na than that of the older group, while that of the older group contained higher levels of O, Ca, P, and Mg compared to the younger group. The Ca/P molar ratio was 1.75±0.39 on average in the younger group. The Ca/P molar ratio was 1.50±0.21 on average in the older group. HA was detected in the younger group, and W was detected in the older group by X-ray diffraction method. The analysis results of EPMA and the result of the X-ray diffraction method were in harmony. It is possible that the difference in crystal type and composition of subgingival dental calculi between the two groups is due to age.

Keyword: subgingival calculus, age changes, crystal, trace element