Remediation of machining medium effect on biocompatibility of titanium-based dental implants by chemical mechanical nano-structuring

Dental implants are commonly manufactured by shaping titanium rods into screws in an oil medium followed by sandblasting. This study compares the biocompatibility of the titanium dental implants machined in an oil versus DI-water environment. Electrochemical evaluations showed that the machining oil leaves residue on the implant. As a remedy, chemical mechanical nano-structuring (CMNS) is implemented to remove oil residue while controlling the surface roughness and surface passivation. Bacteria growth on the oil-machined and sandblasted implants was higher than the implants only machined in oil ( p value 0.014) and DI water ( p value 0.002). Cytotoxicity experiments also showed ~ 5% higher cell concentration on the DI-water-machined implants than the oil-machined implants and ~ 10% higher than the oil-machined/sandblasted implants. After CMNS treatment, both the DI-water and oil-machined implants showed statistically the same cell proliferation ( p value 0.785), indicating that the implants were cleaned from the oil residue. Graphical abstract