Biocompatibility evaluation of domestically-manufactured NiTi-alloys after thermal oxidation of surface / 第二军医大学学报

ABSTRACT

Objective:To compare the tissue biocompatibility of domestically manufactured NiTi alloy before and after thermal surface oxidation under 3 different temperatures.Methods:Domestically manufactured NiTi alloy was oxidized in air (group A)and subjected to 30 min heat treatment at 400℃(group B),500℃(group C),and 600℃(group D)to form different protective oxide surface layers in presence of argon(607.95 kPa).Wire samples from A,B,C and I3 groups were subcutaneously implanted in guinea pigs.Guinea pigs received 317L stainless steel transplantation(group E)and sham-operation group(F)were taken as control.The order of inflammatory cell infiltration and tissue hyperplasia around implanted materials were observed 1,2,4,and 8 weeks after implantation.Results:The peak time of inflammatory cell infiltration and fibrous hyperplasia were at the first and fourth week after implantation.The inflammatory cell infiltration and fibrous hyperplasia were both slight and all met the GB/T 16886.6-1997 in vivo implantation standard.The order of inflammatory cell infiltration and thickness of capsule walls from low to high was F