1. Division of Endodontics and Restorative Dentistry, Department of Oral Functions, Kyushu Dental University, Kitakyushu, Japan;
2. Research and Development Department, Nippon Shika Yakuhin Co., Ltd, Shimonoseki, Japan;
3. Laboratory of Biomaterials, Department of Regeneration Science and Engineering, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan