Animals

Experiments were performed using C57BL/6J mice (male, 3 weeks old) and C.B-17/IcrHsd-Prkdc^scid mice (SCID, male, 6 weeks old) (both from Japan SLC, Inc., Hamamatsu, Japan). Animals were housed at a specific pathogen-free environment in the animal experiment facility of Matsumoto Dental University High-Tech Center. The animals were kept under controlled environmental conditions at 22°C and 50% humidity with a 12 h light/dark cycle, with free access to food and water. All procedures and experiments in this study were performed in accordance with the guidelines laid down by the National Institutes of Health (NIH) in the United States, regarding the care and use of animals for experimental procedures. This study was approved by the Matsumoto Dental University Committee on Intramural Animal Use (Nos. 289 and 364).