The effect of different titanium nitride coatings on the adhesion of Candida albicans to titanium

Objectives

The aim of the present study was an in vitro evaluation of the effects of different titanium nitride (TiN_x) coatings on Candida albicans (C. albicans) adhesion to titanium and to correlate these findings to differences in specific surface characteristics (surface topography, roughness, chemical component, and surface free energy).

Methods

TiN_x coatings were prepared by physical vapour deposition (PVD), a plasma nitriding process or a dual nitriding process. Surface properties were analysed by the optical stereoscopic microscopy, scanning electron microscopy, roughmeter, and drop shape methods. Quantity comparisons of C. albicans on the four surfaces were assessed by cell count and XTT reduction assays. Types of adhesive C. albicans were explored by SEM and confocal laser scanning microscope.

Results

The nitrided modifications were found to influence the surface properties and fungal susceptivity of flat titanium. Compared to flat titanium, fewer adhered C. albicans in yeast form were observed on the TiN-coated surface, whereas the plasma nitrided surface did not show any reduced potential to adhere C. albicans in hyphal or yeast form. The dual nitrided coating showed anti-fungal characteristics, although a small quantity of hyphae were identified. Our findings indicate that the Ti₂N phase is prone to C. albicans hyphae, while the TiN phase inhibits their adhesion.

Conclusions

Different TiN_x phases could influence the characteristics of C. albicans adhesion. TiN coating by PVD could be a potential modification to inhibit C. albicans.