Effect of Remaining Periodontal Ligament on the Healing-up of the Implant Placement

Abstract

Tooth-shaped titanium implants were placed into a tooth socket with adhering periodontal ligament after extraction to examine the regeneration of periodontal tissues from remaining periodontal ligament cells. The extraction forces of the implants were measured with a materials testing machine. The mechanical strength of the peri-implant ligament increased markedly from 14 (25% of control) to 28 (68% of control) days. The implants and surrounding tissues were observed morphologically. The result showed that cementum-like hard tissues were formed on the surface of the titanium implants and there were many collagen fiber bundles between the cementum-like tissues and alveolar bone at 21 and 28 days. These findings suggest that placement of an implant into a socket with periodontal ligament leads to formation of new cementum-like hard tissues with functionally-oriented collagen bundles and development of adequate mechanical strength.