1. Division of Periodontology and Endodontology, Department of Oral Rehabilitation, School of DentistryHealth Sciences University of Hokkaido Ishikari‐Tobetsu, Hokkaido 061‐0293 Japan
2. Postdoctoral Fellow of Japan Society for the Promotion of Science Chiyoda‐ku Tokyo Japan
3. Department of Oral Microbiology, School of DentistryHealth Sciences University of Hokkaido Ishikari‐Tobetsu Hokkaido 061‐0293 Japan
4. Department of Oral Biology, School of Dental MedicineUniversity at Buffalo, The State University of New York Buffalo New York
5. Division of Biomaterials and Bioengineering, Department of Oral Rehabilitation, School of DentistryHealth Sciences University of Hokkaido Ishikari‐Tobetsu Hokkaido 061‐0293 Japan