Biotribocorrosion behavior of titanium in the presence of biofilms

In the oral cavity, restorative surfaces such as of titanium-based implant systems are in contact with several acidic substances originated from dietary intake and microbial metabolism. During the mastication, a simultaneous corrosion-wear process known by Biotribocorrosion can take place on the surfaces which are in relative contact motion. The objective of this work is to investigate the in-vitro simultaneous corrosion-wear behavior of titanium in the presence of biofilms. Electrochemical tests of titanium surfaces covered or not by mixed oral biofilms (Streptococcus mutans and Candida albicans) were carried out in artificial saliva. After stabilization of open circuit potential of titanium in artificial saliva, reciprocating wear sliding tests were performed against an alumina ball at different loads using a tribometer equipped with a test viewer software. Moreover, electrochemical measurements were carried during the wear sliding tests. Worn and unworn surfaces were analyzed by different SEM techniques. Biofilms decreased significantly the friction of titanium surfaces. However, the presence of biofilms affected negatively the corrosion resistance of titanium probably due to acids release from the biofilms.
Comissão Europeia - programa Alban (cod. E06D103407BR)
Fundação para a Ciência e a Tecnologia (FCT) - PTDC/CTM/67500/2006)
Flemish Science Foundation. Scientific Research Community on Surface Modification of Materials (WOG-FWO Vlaanderen)