1. Department of Endodontology; Kyushu University Hospital; Maidashi, Higashi-ku Fukuoka Japan
2. Section of Endodontology & Operative Dentistry; Division of Oral Rehabilitation; Faculty of Dental Science; Kyushu University; 3-1-1 Maidashi Higashi-ku Fukuoka 812-8582 Japan
3. Division of General Oral Care; Kyushu University Hospital; Maidashi, Higashi-ku Fukuoka Japan
4. OBT Research Center; Faculty of Dental Science; Kyushu University; Maidashi, Higashi-ku Fukuoka Japan