TITANIUM DEPOSITION IN REGIONAL LYMPH-NODES AFTER INSERTION OF TITANIUM SCREW IMPLANTS IN MAXILLOFACIAL REGION

The deposition of titanium in regional lymph nodes was studied after i nsertion of endosseous, plasma-spray-coated titanium screw implants in a total of 19 beagle dogs. Five additional animals with no implants s erved as the control group. After killing the animals 9 months postope ratively, the regional lymph nodes were carefully excised, and samples were prepared for histologic examination. Other samples were used to identify foreign particles by energy-dispersive x-ray analysis and for measurement of the titanium concentration in the tissue by flameless atomic absorption spectroscopy. Very fine foreign-body particles could be seen in the histologic sections, and they were identified as titan ium by energy-dispersive x-ray analysis. The atomic absorption analysi s for titanium revealed a significantly higher concentration in the gr oup with implants. The presence of very fine, poorly attached particle s on the plasma-sprayed titanium surface suggests that these particles may be mechanically dislodged from the surface on insertion of the im plants. This suggests that the fine particles may be transported by ph agocytes to the regional lymph nodes, where they could be found withou t any signs of inflammation or foreign-body reaction.