Fig. 2

Implantation and removal of NGF-CS/HA-coating implants in the mandible of Beagle dogs. a The alveolar ridge of a Beagle dog after extraction. b The premolar teeth of a Beagle dog after extraction. c Six months after tooth extraction, 4 NGF-CS/HA-coating implants were implanted in the right mandibular premolar. d A ring bone drill was applied to remove the implants with thin layers of bone tissue