Surface characterization and assessment of biofilm formation on two titanium-based implant coating materials. TiCN and TiN coated disc biofilm

Peri-implantitis, an oral disease driven by microbial inflammation, is one of the leading causes of implant failure. The artificial surfaces used in the implants provide additional surfaces for the bacterial attachment, eventually leading to peri-implantitis. Currently, titanium is the most commonly used material for abutment components; however, there is a constant need to improve the materials' properties for better clinical outcomes. This study compared two titanium-based implant surface materials, titanium carbon nitride (TiCN) and titanium nitride (TiN) by characterizing their hydrophobicity, roughness, and biofilm forming ability. Atomic Force Microscopy and contact angle measurements were employed to determine roughness and surface hydrophobicity. A previously well-established saliva-based biofilm model, representing the majority of microorganisms of the human oral cavity was used for developing in vitro biofilm. The biomass accumulation on the different discs was further evaluated with crystal violet staining and SEM imaging. Additionally, the community profile of the biofilms in the presence of salivary and blood components at different time points was assessed using denaturing gradient gel electrophoresis. Although surface roughness was very similar for both types of surfaces, contact angle measurement showed that TiCN surfaces were more hydrophilic than TiN surfaces. Significantly, a higher bacterial biofilm was observed on TiN compared to TiCN at all-time points. This significant reduction of biofilm formation on TiCN surfaces can be further explored to improve the outcome of implants.