The effect of biological environment on the surface of titanium and plasma-sprayed layer of hydroxylapatite.
The solubility of titanium samples with different surface coatings, i.e., hydroxylapatite (HA) powders, a two-layer coating of ZrO5+HA on a titanium substrate in solution and of tooth implants after long-term functioning in the human organism, was studied. A minimum difference in solubility of titanium samples with different surface finishes (polished or grit blasted) was established. For the HA powders and coatings, the lowest solubility was observed with a coarse-grained HA-B powder and a coating made of that powder. Clinical tests of tooth implants after long implantation times were performed. A titanium implant (implantation 12 y), a titanium implant with a two-layer coating of ZrO5+HA-A (implantation time 4 y) and a titanium implant with a two-layer coating of (Al5O3+3% TiO2)+HA-A (implantation time 6 y) were studied. The results show that the titanium surface and HA-A layers were dissolved. Nevertheless, after 6 y implantation, total removal of HA-A coating from that part of implant set into the bone, was not observed.
Palka
V
V
Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Racianska 75, P.O. Box 95, 830 08 Bratislava 38, Slovakia.
Ivan
J
J
Postrková
E
E
Kolenclak
V
V
Krsek
A
A
Infner
I
I
Koerten
H K
HK