Plasma Treatment to Remove Titanium Surface Contaminants and Improve Implant Biocompatibility: An In Vitro Study

Plasma technology is an emerging method for implant surface decontamination and modification. This in vitro study evaluates the effects of plasma treatment on fibroblast and osteoblast adhesion, proliferation, and differentiation on titanium surfaces. Plasma was applied to machined and rough titanium discs, followed by surface characterization using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and hydrophilicity testing. SEM imaging, cell viability assays, and immunohistologic staining were used to assess cell behaviour in response to treatment, while RNA sequencing evaluated gene expression related to differentiation. Although no significant architecture changes were observed with plasma treatment, XPS revealed a significant reduction in carbon content (p < 0.001), indicating decreased hydrocarbon contamination. Plasma treatment significantly increased surface hydrophilicity in both machined and rough surfaces (p < 0.0001). SEM and IHC imaging showed greater early-stage cell attachment for both fibroblasts and osteoblasts, though differences diminished after 12 h. RNA sequencing revealed time-dependent gene expression in both cell types, with Apln and Crabp2 significantly upregulated at 6 h in the plasma-treated fibroblast group. In conclusion, plasma treatment reduces hydrocarbon buildup, enhances hydrophilicity, promotes early cell attachment, and upregulates genes linked to angiogenesis and proliferation. Further studies are needed to determine its clinical significance in managing peri-implant disease.