[Study on anodic oxidation and hydrothermal treatment of titanium implants with thin hydroxyapatite layers: an implantational test in rabbits].

OBJECTIVE

To learn bone response to commercially pure titanium implants with anodic oxidation followed by hydrothermal treatment in vivo.

METHODS

Tweleve rabbits were averagely divided into three groups. And 36 implants (9 polished, 9 roughened by grit-blasting, 9 treated with anodic oxidation followed by heat treatment and 9 treated with anodic oxidation followed by hydrothermal treatment) were randomly implanted into femur bones of each group rabbits. Implants were harvested at 4 W, 8 W and 16 W respectively. Slice about 30 microns thick were ground with a grinding machine and stained with 1% toluidine blue. The bone-implant interface was observed with light microscopy and scanning electron microscopy. Implant surface element contents were also detected with EDAX.

RESULTS

Woven bone rapidly transferred to lamellae bone at 8 weeks for anodic oxidized implants followed by hydrothermal treatment, which appeared little woven bone and no hydroxyapatite debris between the interfacial zone at 16 weeks. In addition, Ca and P contents increased much more for hydrothermal treated implants after implantation compared with polished implants.

CONCLUSIONS

Anodic oxidation followed with hydrothermal treatment of a titanium fixture could speed up woven bone transferring the lamellae bone at early time of implantation, which meant thin HA layers could accelerate bone healing at the implanted site and might shorten healing time. This superiority need more research in the future.