Ce‐doped defective titanium oxide coating with antibacterial, antioxidant and anti‐inflammatory properties for potential application of peri‐implantitis treatment

Abstract Implant‐related infections and tissue inflammation are the main factors for peri‐implantitis. Lack of antibacterial activity and poor soft tissue sealing property increase the occurrence probability of peri‐implantitis. To prevent and treat peri‐implantitis, cerium‐doped defective titanium oxide coatings are prepared on medical titanium surfaces by plasma electrolytic oxidation and thermal reduction treatment. In the darkness, Ce‐doped defective titanium oxide coatings with micro‐porous structure surface can inhibit the bacteria adhesion to some extent with antibacterial rates of 38.0% against S. aureus and 65.0% against E. coli . Under near infrared (NIR) irradiation, Ce‐doped defective titanium oxide coatings show good photothermal antibacterial activity with antibacterial rates of 99.9% against S. aureus and 99.9% against E. coli . Moreover, with the increasing content of Ce‐doping, the coatings exhibit higher capacity to scavenge hydrogen peroxide (H 2 O 2 ) and 2,2′‐azinobis‐(3‐ethylbenzothiazoline‐6‐sulfonic acid) radical cation (ABTS ·+ ). The coatings with enhanced antioxidant effect can protect human gingival fibroblasts from oxidative stress damage by eliminating reactive oxygen species and promoting initial cell adhesion. Besides, Ce‐doped coatings can regulate the immune microenvironment by up‐regulating the expression of anti‐inflammatory genes and down‐regulating the pro‐inflammatory genes. In vivo animal experiments further confirm the good antibacterial activity of Ce‐doped defective titanium oxide coatings under NIR irradiation and good biosafety. This work provides a novel surface modification strategy for implant abutment, which shows good application prospects for preventing and treating peri‐implantitis.