Adhesion of bioactive glass coating to Ti6Al4V oral implant

Bioactive glass (BAG) is a bioactive material with a high potential as impl ant material. Reactive plasma spraying produces an economically feasible BA G-coating for Ti6Al4V oral implants. This coating is only functional if it adheres well to the metal substrate and if it is strong enough to transfer all loads. To examine these two properties an appropriate mechanical adhesi on test, the moment test, is developed. This test quantifies under a realis tic loading condition the corresponding functional adhesion strength to be >84 MPa in tensile. To get a qualitative insight in the BAG-coating behavio r during loading the mechanical test was combined with finite element analy sis, acoustic emission and microscopic analysis. These analyses showed that the coating withstands without any damage an externally generated tensile stress of 47 MPa. Not only the initial adhesion is determining for the impl ant quality; but more important is the coating functionality after reaction of the BAG. Adhesion testing after two months of in vitro reaction in a si mulated body fluid showed that coating adhesion strength decreased with 10% , but the implant system was still adequate for load-bearing applications. (C) 2000 Elsevier Science Ltd. All rights reserved.