Tissue-engineered ligament: implant constructs for tooth replacement　　

Abstract　　

Aim: A tissue-engineered periodontal ligament (PDL) around implants would represent an important new therapeutic tool to replace lost teeth. The PDL is the key to tooth anchoring; it connects tooth root and alveolar bone, and it sustains bone formation. 　　

Materials and Methods: Cells were isolated from PDL and cultured in a bioreactor on titanium pins. After the formation of multiple cellular layers, pins were implanted in enlarged dental alveolae. 　　

Main Outcome Measures: Cell-covered implants integrated without adverse effects, and induced bone in their vicinity. 　　

Results: A histological examination of a dog model revealed that cells were arranged in a typical ligament-like fashion. In human patients, product safety was ascertained for 6–60 months. Probing and motility assessments suggested that the implants were well integrated with mechanical properties similar to those of teeth. Radiographs demonstrated the regeneration of deficient alveolar bone, the development of a lamina dura adjacent to a mineral-devoid space around the implant and implant migration in an intact bone structure.　　

Conclusions: New tissue consistent with PDL developed on the surface of dental implants after implantation. This proof-of-principal investigation demonstrates the application of ligament-anchored implants, which have potential advantages over osseointegrated oral implants.