Dental plaque formation on teeth and restorative materials plays an important role in the pathogenesis of oral diseases. Newly developed dental materials have been tested for their susceptibility to adhere bacteria causing caries and periodontitis. Numerous factors have been identified to influence oral biofilm formation such as surface roughness, surface free energy and surface chemical composition. Both an increase in surface roughness above the Ra treshold above 0,2 µm and/or of the surface free energy facilitates biofilm formation on restorative materials. Various affinities of oral bacteria adhesion have been reported for different materials such as titanium, resin composites and dental ceramic materials. Several in vitro and in vivo studies have investigated the bacterial adhesion on ceramics in comparison to other dental materials, such as gold alloy, titanium, composite. Almost all of these investigations found lower bacterial adhesion and biofilm formation on ceramics compared to other materials. Biofilm formation on various types of dental ceramics differs significantly. Zirconia, in particular, exhibits low plaque accumulation. In addition to its high strenght, it makes zirconia a promising material for various indications (including implant abutments and telescopic crowns).

Key words: bacteria, biofilm, adhesion, dental materials.