Orthopedic implants are widely used to repair damaged bones caused by injury, aging, or disease. Metals such as titanium alloys are commonly used because they are strong and reliable. However, these materials remain permanently in the body and are often much stiffer than natural bone. This difference can affect how the bone carries load, weaken the surrounding bone over time, and in some cases lead to additional surgeries
To address this challenge, researchers have developed a new type of metal implant designed to support bone healing while also encouraging natural bone regeneration. The new hybrid implant combines a strong titanium alloy framework with zinc, a metal that can slowly dissolve inside the body. This allows the implant to provide mechanical support during healing while gradually creating space for new bone growth.
The study was carried out by Prof. Dr.-Ing. Prashanth Konda Gokuldoss and Early Stage Researcher Mayank Kumar Yadav from the Additive Manufacturing Technologies research group at Tallinn University of Technology, together with an international team. Their paper, published in Advanced Light Materials, introduces a new manufacturing approach that combines 3D printing with pressure-assisted sintering to produce the metallic implant.
The implant consists of a 3D-printed titanium alloy lattice inspired by the natural honeycomb structure. This architecture provides high strength while using less material and allows body fluids and bone cells to move through the structure. The lattice is then filled with zinc, which gradually degrades under physiological conditions.
The idea behind this design is that as the zinc dissolves, it creates additional space for bone tissue to grow into the implant. Meanwhile, the titanium framework remains stable and continues to support the mechanical load. This combination allows the implant to provide strength during the healing phase while promoting bone regeneration.
The resulting material showed improved mechanical strength compared to pure zinc while maintaining a controlled degradation rate. In laboratory tests, the composite achieved a compressive strength of about 292 MPa, which is higher than the reported value for natural bone, and demonstrated a degradation rate of approximately 0.157 mm per year under simulated body conditions. Tests with bone-related cells also indicated good biocompatibility.
“This study shows that it is possible to combine a strong titanium framework with biodegradable zinc in a single implant, so the material can support the bone during healing while gradually creating space for new bone growth,” said Mayank Kumar Yadav.
According to the researchers, this approach represents a promising step toward next-generation orthopedic implants. Further research will focus on understanding the long-term behavior of the implant and optimizing its design for clinical applications.
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Prof. Dr.-Ing. Prashanth Konda Gokuldoss