[1] Nihon Univ, Sch Dent, Dept Periodontol, Matsudo, Chiba, Japan
[2] Nihon Univ, Sch Dent, Res Inst Oral Sci, Matsudo, Chiba, Japan
[3] Tokyo Dent Coll, Dept Periodontol, Tokyo, Japan
[4] Tsurumi Univ, Sch Dent Med, Dept Periodontol, Yokohama, Kanagawa, Japan
[5] Niigata Univ, Div Periodontol, Dept Oral Biol Sci, Grad Sch Med & Dent Sci, Niigata, Japan
[6] Showa Yakuhin Kako, Res Inst, Tokyo, Japan
[7] Denka Seiken, Reagent Res & Dev Dept, Gosen, Niigata, Japan