[1] Osaka Univ, Grad Sch Dent, Dept Prevent Dent, Suita, Osaka 5650871, Japan
[2] Osaka Univ, Grad Sch Dent, Dept Oral Frontier Biol, Suita, Osaka 5650871, Japan
[3] Osaka Univ, Dent Hosp, Div Special Care Dent, Suita, Osaka, Japan
[4] Osaka Univ, Microbial Dis Res Inst, Dept Bacterial Infect, Suita, Osaka 565, Japan