Surface Roughness Value Recommended for the Manufacture of Antibacterial Metal Surfaces: A Review

The manufacturing of antibacterial metal surfaces has been widely studied in the elaboration dental and orthopedic implants. Surface characteristics such as wettability, chemistry, electrostatics, and roughness have been described as factors for avoiding bacterial adhesion. However, surface roughness is still debated among authors regarding its effect on antibacterial surfaces. This paper reviews the existing literature to identify the recommended surface roughness values for metal implants to avoid bacterial adhesion, and it evaluates the different roughness parameters used in this regard. This compilation found no agreement when it comes to the exact roughness that a metal implant's surface should have to avoid bacterial adhesion and the subsequent formation of biofilms. In general, different authors recommend manufacturing smooth surfaces with a nanoscale roughness, smaller than the size of the target bacterium.