Contamination by metallic elements released from joint prostheses.

When a metallic implant is in contact with human tissues, the organism reacts and a corrosion process starts. Consequently, we might observe liberation of metallic debris and wear. Our purpose is to measure the contamination and the migration of these metallic elements in the surrounding tissues of the implant.

Modelling by percolation theory of the behaviour of natural coral used as bone substitute.

We investigate the relevance of site-bond percolation theory to model the resorption and ossification of natural coral implanted in bones. The first step of the process is the vascularization of the implant seen here as a percolation threshold. The resorption and ossification can thus take place by activation of unoccupied sites.

Nuclear methods to characterize biomaterials.

Techniques using X-rays are often used to study biomaterials fields. However, when one is interested by quantitative and very sensitive measurements, it is valuable to develop nuclear instruments and methods, in addition and complement with others. Fast neutron activation is appropriate for non-destructive analysis.

Dissolution Kinetics, Selective Leaching, and Interfacial Reactions of a Bioglass Coating Enriched in Alumina.

Bioglass coatings are interesting for developing a direct bond between prostheses and bone. But the high solubility of these materials limits their application. The addition of alumina can be used to control their solubility, but may inhibit the bonding mechanisms.

Study of implanted biomaterial functionality by diphosphonate molecules labeled with radioactive 99mTc.

An implanted biomaterial can be transformed into young bone after some months, but it has not necessary reached full biofunctionality. Mineral concentration kinetics and crystal-structure studies, still being carried out in our group, are completed here by biofunctionality determinations. A natural coral is implanted in vivo at the cortical level of the femoral diaphyoff++ in rabbits.