Bacterial adhesion on the titanium and zirconia abutment surfaces

Microorganisms harboring the oral cavity, mainly those related to periodontal diseases, are the most potential etiologic factor of failure in long-term implant treatment. The material used for abutment components may influence the adhesion and colonization of microbial species. The aim of this in vivo investigation was to evaluate the biofilm formation on machined (MPT) or cast titanium (CPT) and zirconia abutments (Zc).

Six healthy subjects were enrolled in this randomized crossover clinical investigation. The study was conducted in three phases according to abutment surface evaluated. Each subject used an individual oral splint containing four disks of the same tested substrate, two located in the anterior and two in the posterior region, totalizing 12 specimens for subject. Participants were asked to use the removable intraoral splint during 24 h. DNA checkerboard hybridization method was used to identify and quantify 38 bacterial species colonizing formed biofilm on the abutment substrates.

Pathogens and non-pathogens species were found colonizing the three substrates surfaces. Fusobacterium nucleatum, Neisseria mucosa, Porphyromonas aeruginosa, Peptostreptococcus anaerobios, Staphylococcus aureus, Streptococcus gordonii, Streptococcus parasanguinis, and Tanerella forsythia were the only species with no significant differences over the tested materials (P > 0.05). All the other target species presented significant differences sought by Friedman test (P < 0.0001).

There was a significant difference in the total bacterial count between the three groups. CPT presented the higher mean counts, followed by MPT and Zc. CPT group also showed a higher mean incidence of species than MPT and Zc. The anterior or posterior region of disks placement did not show significant differences in relation to bacterial adhesion.