Biomedical Engineering Reference
In-Depth Information
TABLE 2.2
Examples of Relatively Bioinert Bioceramics
Bioinert Ceramics
References
1. Pyrolitic carbon-coated
devices
Adams and Williams (1978)
Bokros et al. (1972)
Bokros (1972)
Chandy and Sharma (1991)
Dellsperger and Chandran (1991)
Kaae (1971)
More and Silver (1990)
Shimm and Haubold (1980)
Shobert (1964)
2. Dense and nonporous
aluminum oxides
Hench (1991)
Hentrich et al. (1971)
Krainess and Knapp (1978)
Park (1991)
Ritter et al. (1979)
Shackelford (1988)
3. Porous aluminum
oxides
Hench (1991)
Hentrich et al. (1971)
Park (1991)
Ritter et al. (1979)
Shackelford (1988)
4. Zirconia ceramics
Barinov and Bashenko (1992)
Drennan and Steele (1991)
Hench (1991)
Kumar et al. (1989)
5. Dense hydroxyapatites
Bajpai (1990)
Cotell et al. (1992)
Fulmer et al. (1992)
Huaxia et al. (1992)
Kijima and Tsutsumi (1979)
Knowles et al. (1993)
Meenen et al. (1992)
Niwa et al. (1980)
Posner et al. (1958)
Schwartz et al. (1993)
Valiathan et al. (1993)
Whitehead et al. (1993)
6. Calcium aluminates
Hammer et al. (1972)
Hentrich et al. (1971)
Hulbert and Klawitter (1971)
nonstructural support uses are ventilation tubes, sterilization devices (Feenstra and de Groot, 1983),
and drug-delivery devices (see Table 2.3).
2.2.2 Alumina (Al
2
O
3
)
The main source of high-purity alumina (aluminum oxide, Al
2
O
3
) is bauxite and native corundum. The
commonly available alumina (alpha, α) can be prepared by calcining alumina trihydrate. The chemical
composition and density of commercially available “pure” calcined alumina are given in Table 2.4. The
American Society for Testing and Materials (ASTM) specifies that alumina for implant use should con-
tain 99.5% pure alumina and less than 0.1% combined SiO
2
and alkali oxides (mostly Na
2
O) (F603-78).
Alpha alumina has a rhombohedral crystal structure (
a
= 4.758 Å and
c
= 12.991 Å). Natural alu-
mina is known as sapphire or ruby, depending on the types of impurities which give rise to color. The
