This study examined the initial attachment of Streptococcus sanguis G9-B and Actinomyces viscosus T14V to saliva-treated powdered enamel and titanium surfaces. Using an in vitro adherence model, significantly lower numbers of Actinomyces viscosus T14V bound to the saliva-treated titanium surface when compared to that of the similarly treated enamel. The binding of Streptococcus sanguis G9-B to titanium or enamel did not vary significantly. A comparison of the percentage of cells bound to the titanium surface revealed that S sanguis cells attached in significantly higher numbers when compared to the A viscosus cells. Schlagwörter: Actinomyces, adherence, Streptococcus, titanium