Titanium Dioxide/Graphene Oxide Composite Coatings for 316 Stainless Steel Dental Implants.

Stainless steel has been used in orthopedics and orthodontic fields. However, it cannot be used for fabrication of dental implants due to its inertness, low biocompatibility and weak resistance to corrosion. A composite coating of titanium oxide /graphene oxide has been prepared for stainless steel to improve its biological properties. Stainless steel discs were polished, cleaned and pre-treated with a mixture of HNO3 and HF acid for 15 min. The composite coating composed of TiO2 produced by sol-gel technique and doped with 0.75 wt% graphene oxide. XRD, SEM-EDX and AFM were employed to characterize the composite coating. The anti-bacterial action of the composite coating was investigated against S. aureus and E. coli. The corrosion resistance of coated and noncoated samples was assessed in SBF using electrochemical technique. Cytotoxicity was assessed using osteoblast-like cells. The wettability was determined by contact angle, and bioactivity assessed by immersion in SBF. The results revealed that the composite coating was dense with few micro-cracks, and was not cytotoxic to osteoblast-like cells. The composite coating reduced bacterial colonies and the corrosion rate of the steel was improved. The wettability of the sample was increased with the composite coating and apatite formation appeared after 21 days.