Diamond-like carbon films over reconstructive TMJ prosthetic materials: Effects in the cytotoxicity, chemical and mechanical properties Publication date: July–September 2019 Source: Journal of Oral Biology and Craniofacial Research, Volume 9, Issue 3 Author(s): Alecsandro de Moura Silva, Viviane Maria Gonçalves de Figueiredo, Renata Falchete do Prado, Gabriela de Fátima Santanta-Melo, Milagros del Valle El Abras Ankha, Luana Marotta Reis de Vasconcellos, Argemiro Soares da Silva Sobrinho, Alexandre Luiz Souto Borges, Lafayette Nogueira Junior Abstract Increasingly more young patients have been submitted to reconstruction of the Temporomandibular Joint (TMJ), so, the prostheses must to present more functional longevity. Objective To evaluate the effect of diamond-like carbon film (DLC) over titanium alloy (Ti6Al4V) and polyethylene (UHWPE) samples, their mechanical and chemical properties and cellular cytotoxicity. Methods Titanium and UHWPE specimens, with 2.5 cm in diameter and 2 mm thickness were coated through plasma enhanced chemical vapor deposition (PECVD) with DLC or DLC doped with silver (DLC-Ag). Scanning electron microscopy (SEM) morphological analysis, Energy-dispersive spectroscopy (EDS) chemical analysis, scratching test, mechanical fatigue test, surface roughness analysis, and cellular cytotoxicity were performed. Data were statistically analyzed using one-way ANOVA (p < 0.05) or two-way ANOVA and multiple comparison Tukey test. Results In the SEM analysis, morphological differences were observed on substrates after DLC deposition. The film chemically modified the substrate surfaces, according to the EDS analysis. The initial critical load failure occurred at 6.1 N for DLC and 9.7 N for the DLC-Ag film. The DLC film deposition over the polyethylene promoted a decrease in the polymer's damaged area after mechanical fatigue cycling. The cytotoxicity analysis demonstrated less biocompatibility in experimental groups, when compared to control, however, increased biocompatibility was observed, at 10 days, in all groups. Conclusion The diamond-like carbon coating enhanced the chemical and mechanical properties from substrates, however modified biological interaction course of the titanium alloy (Ti6Al4V) and polyethylene (UHWPE) samples. Parameters for film deposition remain to be improved in order to obtain best biocompatibility.