Ultrananocrystalline diamond coatings for the dental implant: electrochemical nature

Titanium (Ti) and its alloys are currently used as biomaterials for dental implants. However, titanium and its alloys suffer electrochemical corrosion in the oral environment. Ultrananocrystalline diamond (UNCD) coating is a promising coating material with exceptional biocompatibility, excellent osseointegration, high wear resistance and extreme resistance to chemical attack for producing a new generation of long-life dental implants. The main objective of this work was to investigate the basic electrochemical behavior of UNCD-coated samples of commercially pure titanium (Cp-Ti/Ti-2) and titanium alloy (Ti–6Al–4V/Ti-5) at three different pH conditions of artificial saliva. All titanium and titanium alloy samples of four groups were used: (a) control Ti-2, (b) UNCD-coated Ti-2, (c) control Ti-5 and (d) UNCD-coated Ti-5. For each group, electrochemical analysis was performed at pH 3, 6·5 and 9·0. In the electrochemical tests, the evolution of potential was higher in the UNCD-coated Ti-2 and UNCD-coated Ti-5 than in the uncoated samples. Potentiodynamic (E_corr, I_corr) and impedance measurements also showed improvement in the electrochemical behavior of both UNCD-coated titanium samples for all three pH conditions. These preliminary findings indicate that UNCD coatings could be considered for the next generation of the dental implants, to improve their performance.