"At present the use of 316L Stainless Steel is limited to temporary devices with a service life not exceeding 12 months."
"Stainless Steel is the least biocompatible alloy. Titanium alloy offers a clear advantage in corrosion resistance and general biocompatibility."
"Minimal fibrosis is typically observed around Titanium alloys, whereas fibrous layers as much as 2mm thick are encountered with Cobalt-Chrome and especially, steel implants."
Source: "Characteristics of metals used in implants"
Journal of Endourolgy. Volume 11, number 6, 6/12/1997, Irena Gotman, PhD >> Download STENT ARTICLE (.pdf file, 1315Kb)
"Titanium alloys are wholly resistant to fretting corrosion, in comparison the cast cobalt chromium is fairly resistant, and Stainless Steel is particularly suceptible to fretting."
"In cardiovascular applications, titanium is being used in heart valves and pacemakers with no report of corrosion."
"More recent animal studies confirmed the early conclusions, it appears that titanium may be actually better tolearted than the Stainless Steel and cobalt chromium."
"The range of potentials recorded in volts were as follows : 0.2 to 0.35 for Stainless Steel, 0.3 to 0.4 for cobalt chromium, and 0.45 to 0.55 for titanium." (The higher is the potential, the more resistant to corrosion it is).
Source: "Corrosion resistance of Titanium - Surgical Implant Alloys : A Review"
American Society for Testing and Materials >> Download STENT ARTICLE (.pdf file, 381Kb)
"Simpson et al performed a study involving implants made of Stainless Steel, Cobalt and Titanium. Clinical symptoms of pain, swelling and inflammation were observed with the first two metals but none with Titanium. Infection was not reported with titanium. Such observation distinguish the 2nd generation metal Titanium from conventional materials Stainless Steel and cobalt chromium molybdenum alloy."
"Metallic foreign body can interact with tissue in 3 ways: electron exchange (redox), proton exchange (hydolisis), by organic molecule binding. All three reactions occur for stainless steel but none for titanium"
"Tissue impregnation by corrosion products is equivalent to a chemical insult. Metals ions can unite with protein to form an antigen. Such complex formation are known to occur with nickel, cobalt and chromium but are absent from titanium."
Source: "Metal implants and Surface reactions"
Injury 1996, 27 Suppl 3: SC16-22 >> Download STENT ARTICLE (.pdf file, 420Kb)
"On the Titanium oxide films no platelet aggregation was found, almost no red blood cells were damaged, and almost no fibrin was found on the surface. Howewer, all three characteristics were found on the surface of LTI Carbon."
Source: "In vivo, investigation of blood compatibility of Titanium oxide films, Shangai Cardiovascular Institute"
Feng Zhang, Zhihong Zheng, Yuchen, Zhonghan hospital >> Download STENT ARTICLE (.pdf file, 145Kb)
OTHER ARTICLES
Titanium as a metal for implantation >> Download STENT ARTICLE (.pdf file, 875Kb)