Biomedical Engineering Reference
In-Depth Information
TABLE 2.2. Lattice Parameters of Mineral, Synthetic and Biologic Apatites
Lattice
parameters
(
±
0.003A)
Apatite
Substituent
a
- axis
c
- axis
Mineral
OH - Apatite (Holly Springs)
—
9.422
6.880
F - Apatite (Durango, Mex)
F - for - OH
9.375
6.880
Dahllite (Wyoming)
CO
3
- for - PO
4
9.380
6.889
Staffelite (Staffel, Germany)
CO
3
- for - PO
4
, F - for - OH
9.345
6.880
Marine phosphorites (USA)
CO
3
- for - PO
4
, F - for - OH
9.322
6.882
Synthetic (non- aqueous)
a
OH - apatite
—
9.422
6.882
F - apatite
F - for - OH
9.375
6.880
Cl - apatite
Cl - for - OH
9.646
6.771
CO
3
- apatite
CO
3
- for - OH (Type A)
9.544
6.859
Synthetic (aqueous
b
)
OH - apatite
—
9.438
6.882
OH - apatite
HPO
4
- for - PO
4
9.462
6.879
F - apatite
F - for - OH
9.382
6.880
(Cl,OH) - apatite
Cl - for - OH
9.515
6.858
CO
3
- apatite
CO
3
- for - PO
4
(Type B)
9.298
6.924
CO
3
- F - apatite
CO
3
- for - PO
4
(Type B) and F - for - OH
9.268
6.924
Sr - apatite
Sr - for - Ca
9.739
6.913
Pb - apatite
Pb - for - Ca
9.894
7.422
Ba - apatite
Ba - for - Ca
10.162
7.722
Biologic apatite
Human enamel
(CO
3
,HPO
4
) - for PO
4
9.441
6.882
Shark enameloid
CO
3
- for - PO
4
(Type B) and F - for - OH
9.382
6.880
[57,64]
The fi rst application of calcium phosphate for bone repair was reported in
1920 [1]. It was not until the early 1970s, but especially in the 1980s and 1990s, that
extensive studies on apatites (particularly calcium hydroxyapatite, HA) and some
calcium phosphates (especially
-TCP) have been investigated for their potential
use as bone substitute materials [2,18,46]. Commercial calcium phosphate prod-
ucts used for bone repair, augmentation or as scaffolds for tissue engineering
include: apatites (HA and calcium-defi cient apatites),
β
β
- TCP, biphasic calcium
phosphates, BCP (intimate mixtures of HA and
- TCP) [2,12,15,18,20,46,54,62,
64,70,75]. HA is also used to deposit bioactive coatings on orthopedic and dental
implants [30,82]. Experimental apatites (CHA, CFA) and other calcium phos-
phates (e.g., OCP, Mg- or Zn-substituted
β
β
-TCP) are investigated as possible
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