Micro- and nano-structured 3D printed titanium implants with a hydroxyapatite coating for improved osseointegration

With the increasing demand for low-cost and more efficient dental implants, there is an urgent need to develop new manufacturing approaches and implants with better osseointegration performance. 3D printing technology provides enormous opportunities for the rapid fabrication of a new generation of patient-tailored dental implants with significantly reduced costs. This study presents the demonstration of a unique model of titanium implants based on 3D printing technology with improved osseointegration properties. Titanium alloy (Ti6Al4V) implants with a micro-structured surface are fabricated using a selective laser-melting process followed by further nano-structuring with electrochemical anodization to form titania nanotubes (TNT) and subsequent bioactivation by a hydroxyapatite (HA) coating. The osseointegration properties of the fabricated implants were examined using human primary osteoblasts and cell line models. The results showed significantly increased protein adsorption, cell adhesion and cell spreading. The expression of the late osteoblast/osteocyte genes GJA1 and PHEX was also enhanced, indicating a cell maturation effect and the promotion of mineralization on the surface. These results suggest that 3D printing technology combined with electrochemical nano-structuring and HA modification is a promising approach for the fabrication of Ti implants with improved osseointegration and provides potential alternatives to conventional dental implants.