Changes of nickel and titanium in some organs and tissues of dogs after the en-dosseous implantation of shape memory alloy

The analyses were performed for the content of nickel and titanium in samples of liver,kidney,spleen and nasopharyngeal mucosa taken from eight dogs after irnplanting ten shape memory NiTi alloy en-dosseous dental implants in each dog for 2-6 months.Ten dogs were taken for the control.The results showed that,except spleens,there are significant increases for the content of nickel in all theorgans and tissues of experimental dogs（P＜0.05）,especially in kidneys（P＜0.01）;and no significant differ-ences for titanium in all the organs and tissues between the experimental group and the control.The results indicated that the stability of the shape memory NiTi alloy in animal bodys is relative, butthere are some variances in the released quantity between nickel and titanium;the further study should be tak-en to make clear the evaluation of biological safety for the tendency to increase the content of nickel in liver,kidney and nasopharyngeal mucosa of the experimental dogs;and the study also should be made in deep on themechanism and the differences of the affinity of various organs and tissues to nickel and titanium.