1 Division of Pathology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, 1-1 Keyakidai, Sakado-shi, Saitama, 350-0283, Japan. idef@dent.meikai.ac.jp.
2 Department of Diagnostic Pathology, Tsurumi University Dental Hospital, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, 230-8501, Japan.
3 Division of Pathology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, 1-1 Keyakidai, Sakado-shi, Saitama, 350-0283, Japan.
4 Department of Operative Dentistry, Cariology and Pulp Biology, Tokyo Dental College, 2-9-18 Kandamisaki-Cho, Chiyoda-ku, Tokyo, 101-0061, Japan.