ISSN:
1573-4838
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
,
Technology
Notes:
Fifty-four cylinders (2.8 mm in diameter) machined from hot isostatically pressed titania (TI) and titania-hydroxyapatite (TI/HA-15 vol%) sintered at 925°C, as well as commercially pure titanium (c.p. Ti), were implanted in the fermoral cortical bone of New Zealand white rabbits for 1, 3 and 12 months. The shear strength between bone and implant was measured by a push-out test. The TI/HA composite showed a significantly higher bonding strength to bone compared to c.p. Ti at all times, while no differences were observed between TI and c. p. Ti at 1 and 3 months after implantation. Titania-based materials had a significantly higher bonding strength than that of c.p. Ti one year after implantation. The results indicate that bioactivity of HA in TI/HA composite contributes to the early bone apposition reflected by high bonding strength, while the stability of the oxide, determines the development of long-term bonding strength. Both effects may be explained by the level and type of ions released from the ceramic implant. HA has a positive conduction to bone ingrowth while TI has a limited interaction to the bone apposition due to the extraordinary low ion release in vivo. Under light microscopy, similar patterns of bone-implant interfaces were seen from titania-based materials and c.p. Ti in 3-month samples, indicating high biocompatibility of these materials. However, histological evaluation by light microscope cannot identify the differences between physical contact and chemical bonding of implant-bone interface, and thus does not give information on bonding mechanism and the level of shear stresses developed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00123369
