Can an integral forming immunoassay be the next-generation standard test to evaluate the long-term integration of implant materials?Wednesday (10.05.2017) 09:40 - 10:00 Part of:
Ceramic materials like zirconium oxide have gained increased interest as a biomaterial for dental implants. They provide not only better aesthetical properties but also an improved biocompatibility and a mechanical strength comparable to standard titanium implants. Bioceramics don‘t oxidize or corrode, giving them an advantage over metal implants. There are many factors, like material surface characteristics, protein adsorption, type of adjacent cell and surrounding tissue, influencing the interaction at the biointerface between a biological system and a material surface. To accept a material as biocompatible a number of cell biological tests (ISO10993-5) are carried out as standards using murine or human fibroblasts to measure cytotoxic effects. Additionally, there are only a few standardized tests (ISO10993-4) of medical devices for blood interactions due to the complexity and variability of patient specific blood response and immunity. However, the primary adhesion of blood proteins during first blood contact, which is crucial for a problem-free integration of the implant in the body, has not been addressed. Certainly, all previous cell-based tests can make a statement regarding biocompatibility, but only within a limited time frame in vitro.
In this project, we developed Yttrium stabilized zirconium oxide with a micro- and macro-structured surface. The surface structuring was not carried out by means of additive and/or subtractive methods, as usual, but was produced by means of slip casting during the shaping of the ceramic. We than applied standard test methods for biocompatibility and hemocompatibility adapted to ceramic and equally structured TiAlV. We established protein- and cell-based assays using specific blood proteins, like albumin, and the human osteoblast cell-line MG-63. We could detect initial structural effects on cell viability and metabolic cell activity comparing different biological assays. Hereby, we could improve the test procedure and obtained a detailed picture of cell morphology and growth behavior on the substrate.