Ultrastructure of ceramic-bone interface using hydroxyapatite and beta-tricalcium phosphate ceramics and replacement mechanism of beta-tricalcium phosphate in bone.
Hydroxyapatite (HA) and beta-tricalcium phosphate (beta-TCP) are useful for grafting and augmentation of bone tissue. Observation by transmission electron microscopy (TEM) was done to investigate the ultrastructures at the interfaces between the biomaterials and the adjacent tissue, and osteogenesis around the biomaterials in the present study. HA and beta-TCP ceramics were used in disk forms which had macropores and micropores, and were implanted between the parietal bone and the cranial periosteum of rats. Specimens were prepared for observation at 4 and 8 weeks postoperatively. The microscopic results indicated that an intervening layer was present on the surface of HA, whereas it was not present on the surface of beta-TCP. A characteristic fibrillar structure was observed in the intervening layer between HA and bone under decalcification by HCl. In beta-TCP, in reticular structures observed close to the bone tissue by optical microscopy, calcification and sparse collagen fibers were interspersed among the granules of beta-TCP. In addition, close to the interface between beta-TCP and bone, many osteocytes with numerous processes were present. Some processes were elongated towards the interface. These results revealed the difference in the ultrastructures of the interfaces between HA and beta-TCP, and the dissolution mechanism of beta-TCP in bone.
Removable Prosthodontics and Stomatognathostatic Rehabilitation, Department of Oral Functional Science, Graduate School of Dental Medicine, Hokkaido University, North 13, West 7, Kita-ku, Sapporo 060-8586, Japan. fujita@den.hokudai.ac.jp
Rumi
R
Fujita
Atsuro
A
Yokoyama
Yoshinobu
Y
Nodasaka
Takao
T
Kohgo
Takao
T
Kawasaki
D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D001842:Bone and Bones / Q000648:ultrastructure*; D002130:Calcium Phosphates / Q000737:chemistry*; D002516:Ceramics / Q000737:chemistry; D017886:Durapatite / Q000737:chemistry*; D017348:Microscopy, Electron, Scanning Transmission; D010012:Osteogenesis; D019736:Prostheses and Implants; D051381:Rats; D040521:Subcutaneous Tissue / Q000648:ultrastructure; D013499:Surface Properties
D001672:Biocompatible Materials; D002130:Calcium Phosphates; C485817:beta-tricalcium phosphate; D017886:Durapatite