TiO2 Nanocoatings with Controllable Crystal Type and Nanoscale Topography on Zirconia Implants to Accelerate Bone Formation

Nan Li; Zhichao Liu; Guanqi Liu; Zhi Wang; Xianwei Guo; Chuanbin Guo; Jianmin Han

doi:10.1155/2022/8650659

TiO₂ Nanocoatings with Controllable Crystal Type and Nanoscale Topography on Zirconia Implants to Accelerate Bone Formation

Bioinorg Chem Appl. 2022 Apr 12:2022:8650659. doi: 10.1155/2022/8650659. eCollection 2022.

Authors

Nan Li¹, Zhichao Liu¹, Guanqi Liu^{1

2}, Zhi Wang³, Xianwei Guo⁴, Chuanbin Guo⁵, Jianmin Han¹

Affiliations

¹ Department of Dental Materials, National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, NMPA Key Laboratory for Dental Materials, Peking University School and Hospital of Stomatology, Beijing 100081, China.
² School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China.
³ Second Clinical Division, School and Hospital of Stomatology, Peking University, Beijing 100081, China.
⁴ College of Materials Sciences and Engineering, Key Laboratory of Advanced Functional Materials, Education Ministry of China, Beijing University of Technology, Beijing 100124, China.
⁵ Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing 100081, China.

Abstract

In dentistry, zirconia implants have emerged as a promising alternative for replacing missing teeth due to their superior aesthetic performance and chemical stability. To improve the osseointegration of zirconia implants, modifying their surface with hierarchical micro/nanotopography and bioactive chemical composition are two effective ways. In this work, a microscale topography was prepared on a zirconia surface using hydrofluoric acid etching, and then a 50 nm TiO₂ nanocoating was deposited via atomic layer deposition (ALD). Subsequently, an annealing treatment was used to transform the TiO₂ from amorphous to anatase and simultaneously generate nanoscale topography. Various investigations into the coating surface morphology, topography, wettability, and chemical composition were carried out using scanning electron microscopy, white light interferometry, contact-angle measurement, X-ray diffraction, and X-ray photoelectron spectroscopy. In addition, in vitro cytocompatibility and osteogenic potential performance of the coatings were evaluated by human bone marrow mesenchymal stem cells (hBMSCs), and in vivo osseointegration performance was assessed in a rat femoral condyle model. Moreover, the possible mechanism was also investigated. The deposition of TiO₂ film with/without annealing treatment did not alter the microscale roughness of the zirconia surface, whereas the nanotopography changed significantly after annealing. The in vitro studies revealed that the anatase TiO₂ coating with regular wavelike nanostructure could promote the adhesion and proliferation of osteoblasts and further improve the osteogenic potential in vitro and osseointegration in vivo. These positive effects may be caused by nanoscale topography via the canonical Wnt/β-catenin pathway. The results suggest that using ALD in combination with annealing treatment to fabricate a nanotopographic TiO₂ coating is a promising way to improve the osteogenic properties of zirconia implants.