Surface-specific outcomes of mechanical debridement with titanium, chitosan and nitinol brushes on titanium dental implant surfaces

Dental implants are susceptible to peri‑implant inflammation caused by bacterial biofilms, with surface properties playing a key role in bacterial adhesion and osseointegration. While mechanical debridement is essential for biofilm removal, consensus on the optimal tool remains limited. In this study, we evaluate the impact of a titanium, a chitosan and a nitinol brush on the surface properties of four titanium dental implant surfaces: OsseoSpeed®-like, SLActive®-like, machined, and polished. Profilometry, contact angle measurements, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) were used to assess the surface properties and chemistry. SEM and profilometry revealed that the titanium and nitinol brushes altered the morphology and topography of the rough OsseoSpeed®-like and SLActive®-like surfaces, while these effects were less pronounced on machined surfaces. Conversely, the chitosan brush caused minimal changes, but its bristles wore down quickly by physical abrasion, increasing surface carbon as detected by EDX and identified by XPS as organic material. Conversely, XPS confirmed that carbon contamination in samples treated with metal brushes was primarily environmental. The increased hydrophobicity observed across all groups was linked to carbon contamination. Polished surfaces remained unaffected by mechanical debridement. The chitosan brush showed minimal surface alterations, but the rapid bristle wear left organic residues that increased hydrophobicity. The titanium and nitinol brushes caused more pronounced surface changes, while contributing to increased hydrophobicity through environmental carbon contamination during debridement. Dental implant surface properties, including topography, morphology, wettability, and surface chemistry, play a critical role in bacterial adhesion and osseointegration. Selecting an optimal mechanical debridement instrument requires balancing the effective removal of biofilm with the impact on the implant surface properties.