Oral biofilm formation on the titanium and zirconia substrates.

The aim of this randomized crossover investigation was to assess the biofilm formation on two titanium and one zirconia substrates in relation to the topography and surface roughness of the materials. Twenty-four discs specimens for each evaluated material (Machined pure titanium, Cast pure titanium, or Zirconia) were evaluated after oral cavity exposure in six healthy subjects. The study was conducted in 3 phases according to the material evaluated. Each subject was asked to use a removable splint containing 4 disks of the same tested substrate, 2 located in the anterior, and 2 in the posterior region. Participants were asked to use the intraoral splint during 24 h. The total biofilm covering on the discs was evaluated by 1% of neutral red staining. EMV and surface roughness was carried out to correlate with the biofilm found between different substrates. Data showed higher mean roughness values for zirconia (Zc) when compared with titanium specimens (MPT and CPT; P < 0.001). MPT and CPT presented no differences between them (P > 0.05). The mean percentage (%) of covering biofilm on substrates was 84.14 for MPT, 86.22 for CPT and 90.90 for Zc. There were no significant differences in the total area of formed biofilm among the tested groups. No correlation was found between surface roughness and the total amount of formed biofilm in the groups.