Influence of surface modifications to titanium on oral bacterial adhesion in vitro

The influence of surface modifications to titanium on the initial adherence of Porphyramonas gingivalis ATCC33277 and Actinobacillus actinomycetemcomi tans ATCC43718 was evaluated. Surface modifications were performed with dry processes including ion implantation (Ca+, N+, F+), oxidation (anode oxida tion, titania spraying), ion plating (TiN, alumina), and ion beam mixing (A g, Sn, Zn, Pt) with Ar+ on polished pure titanium plates. Comparatively lar ge amounts of P. gingivalis and A. actinomycetemcomitans adhered to polishe d titanium plates. The degree of P, gingivalis adhesion showed a positive c orrelation with surface energy and the amount of calcium-ion adsorption. Ad herence of both P. gingivalis and A. actinomycetemcomitans increased on cal cium-implanted surfaces compared with polished titanium surfaces, whereas a dherence of P, gingivalis was remarkably decreased on alumina-coated surfac es. These findings indicate that titanium implants exposed to the oral cavi ty require surface modification to inhibit the adherence of oral bacteria, and that surface modification with a dry process is useful in controlling t he adhesion of oral bacteria as well as ensuring resistance against wear. ( C) 2000 John Wiley & Sons, Inc.