Influence of surface modifications to titanium on antibacterial activity in vitro

The antibacterial effect of surface modifications to Titanium on Porphyromo nas gingivalis ATCC 33277 and Actinobacillus actinomycetemcomitans ATCC 437 18 was evaluated. Surface modifications were performed with dry processes i ncluding ion implantation (Ca+, N+, F+), oxidation (anode oxidation, titani a spraying), ion plating (TIN, alumina), and ion beam mixing (Ag, Sn, Zn, P t) with Ar+ on polished pure titanium plates. F+-implanted specimens signif icantly inhibited the growth of both P. gingivalis and A. actinomycetemcomi tans than the polished titanium. The other surface-modified specimens did n ot exhibit effective antibacterial activity against both bacteria. No relea se of the fluorine ion was detected from F-implanted specimens under dissol ution testing. This result and the characterization of the F+-implanted sur faces suggested that the possible antibacterial mechanism of the F+-implant ed specimen was caused by the formation of a metal fluoride complex on the surfaces. In addition, F+-implanted surfaces did not inhibit the proliferat ion of fibroblast L929-cells. These findings indicate that surface modifica tion by means of a dry process is useful in providing antibacterial activit y of oral bacteria to titanium implants exposed to the oral cavity. (C) 200 1 Elsevier Science Ltd. All rights reserved.