Trace elements cartography by the PIXE method at the interfaces of an implant coated with bioglass

Osteointegration of an implant is related to migrations of atomic elements between the implant, the coating biomaterial and the bone site. In our expe riments, a metallic alloy, Ti 6Al 4V, was coated with a bioactive glass and implanted in thighbone of ovine. The analytical method consists of irradia ting a section of the sample by scanning small areas of the interfaces with a 3 MeV proton beam. The emitted X-rays are detected by a Si semiconductor . The scanning reveals the presence of traces of Fe, Zn and Sr in addition to major elements such as Ca, P and Si. After 3 months of implantation, a g el appears between metallic implant and bone. The trace element signals in the gel are more intense than in mature bone. Osteoconduction leads to neof ormed bone founding in which the signals of these elements are however less intense than in mature bone. Using the PIXE method, we can distinguish and evaluate the degree of bone remodeling around the implant. We detect also Ti and Al contamination in the surrounding region: the presence of these el ements delay the new bone formation around the implant.