Biomedical Engineering Reference
In-Depth Information
Table 7.1
First, second and third generation bioceramics
Type of bioceramic
In vivo
reactivity
Examples
1st generation:
Bioinert
Isolated by a
Alumina: Al
2
O
3
non-absorbable
non-adherent
Zirconia: ZrO
2
fibrous capsule
Carbons, mainly pyrolytic and as fibres in
composites
2nd generation:
Biodegradable
Dissolved
Calcium phosphates
resorbable
after a specific
Calcium sulphate
time
Calcium phosphates and sulphates
+ ZnO, Al
2
O
3
, Fe
2
O
3
Coralline CaCO
3
Bioactive
Tightly bonded
Hydroxyapatite (HA), pure and substituted
surface reactive
to living tissues
Hydroxycarbonate apatite (HCA)
Glasses: by melting and sol-gel
Glass ceramics: A/W glass-ceramic
®
and
Ceravital
®
Bioglass
®
: in particulate form
3rd generation:
Stimulating
scaffolds of
living tissues
Porous bioactive and biodegradable
biologically
regeneration
ceramics
active
Advanced bioceramics: mesoporous
molecules
materials, organic-inorganic hybrids
Biomineralization processes
Four more abundant inorganic phases
Aragonite
CaCO
3
Hydroxyapatite
Ca
10
(PO
4
)
6
(OH)
2
and “Ca phosphates”
Opal
SiO
2
-nH
2
O
Calcite
CaCO
3
* Egg shells
* Hard tissues in
invertebrates
* Algae
* Inferior
zoological
species
7.4
Four more abundant inorganic phases formed by
biomineralization processes.
* Inorganic phase
of hard tissues
in mammals
* Vertebrates
basic calcium phosphate. as indicated earlier, bones of vertebrate animals
are organic-inorganic composite materials whose structure can be briefly
described as follows: the inorganic component is a carbonated and calcium-
deficient non-stoichiometric hydroxyapatite. These biological apatite crystals
