Fabrication and properties of functionally graded dental implant

Dental implants with functionally graded structures composed of titanium (Ti) and ceramic hydroxyapatite (HAP) were fabricated to satisfy both mechanical and biocompatible property requirements. Specimens containing up to Ti/50%HAP functionally graded material (FGM) with the dimensions 6 phi x 15 mm were successfully fabricated by CIP and sintering process. Miniature (2 phi x 10 mm) specimens of Ti, Ti/20%HAP FGM and Ti/30%HAP FGM implants were then made and inserted into femora of ten week-old Wistar strain rats to evaluate their biocompatibility. After 1, 2 and 4 weeks of implantation, the rats were killed and tissue blocks containing the implant material were embedded in resin. Observation of bone formation around the implant was performed by both the conventional method by optical microscopy using specimens stained with toluidine blue and the EPMA mapping method using unstained specimens. The observed area of new bone formation was in good agreement for both the light microscopy and EPMA elemental mapping method. Pure Ti and Ti/HAP FGM specimens showed no inflammation. When pure Ti and Ti/HAP FGM specimens were compared, Ti/HAP FGM showed better biocompatibility. (C) 1997 Elsevier Science Limited. All rights reserved.