Abstract
Department of Operative Dentistry and Endodontology, Kagoshima University Dental School, Kagoshima 890-8544, *Department of Preventive Dentistry, Kyushu University Faculty of Dentistry, Fukuoka 812-8582, †Department of Clinical Laboratory Medicine, Kagoshima University Medical School, Kagoshima 890-8520 and ‡Department of Microbiology and Immunology, Tohoku University School of Dentistry, Sendai 980-8575, Japan
Corresponding author: Dr M. Torii (e-mail: toriim{at}dentb.hal.kagoshima-u.ac.jp ).