Dental implant treatment could become simpler and potentially less invasive with a new bi-layered implant developed by Indian researchers, who have combined titanium alloy and zirconia into a single integrated structure.
The design, developed by researchers at the International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), an autonomous institute under the Department of Science and Technology (DST), seeks to overcome some of the limitations of conventional multi-component implants and reduce the need for multiple surgical procedures.
A conventional dental implant typically has three parts — a fixture anchored in the jawbone, an abutment connecting it to the artificial tooth and a crown. The junction between the fixture and abutment can undergo tiny movements, or micromovements, which may affect implant stability and bone integration over time. The multi-component approach can also require more than one surgical intervention, adding to treatment time, discomfort and clinical complexity.
A scientist from the DST said that the ARCI researchers have integrated Ti6Al4V, a titanium alloy, with yttria-stabilised zirconia (YSZ), a ceramic commonly used in dental applications.
In the proposed implant, titanium alloy forms the load-bearing section designed to integrate with the jawbone, while zirconia constitutes the visible crown region. The arrangement aims to combine the strength and biocompatibility of titanium with zirconia’s tooth-like appearance, wear resistance and corrosion resistance, he added.
Both materials have limitations when used independently. Titanium alloys are strong and widely used in biomedical applications, but their performance in the moist oral environment can raise concerns related to corrosion and, in some cases, gum recession. Zirconia offers superior aesthetics and corrosion resistance, although prolonged exposure to moisture can lead to degradation through hydrolysis.
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To integrate the two, the researchers used Spark Plasma Sintering (SPS), an advanced powder-metallurgy process. A specially designed tapered graphite die helped manage temperature during processing, enabling the two materials—which have different sintering requirements—to be densified together.
The resulting bi-layered structure achieved 99.5% density. Structural and microscopic analysis showed a well-bonded interface without visible cracks, pores or delamination. Researchers also found no significant elemental diffusion between the metal and ceramic, indicating a stable transition between the two layers.
Mechanical tests showed hardness of up to 1,350 HV, compressive strength of about 1,550 MPa and flexural strength of around 310 MPa, indicating considerable mechanical strength for further implant development.
Laboratory biological tests also produced encouraging results. Tests using L929 mouse fibroblast cells recorded metabolic activity above 90% across the concentrations examined, indicating non-cytotoxic behaviour. Haemolysis testing showed negligible damage to red blood cells.
However, the findings are still at the laboratory stage. They do not establish how the implant would perform in patients over several years. Clinical studies will be necessary to assess safety, durability, bone integration and effectiveness before the technology can be considered for routine dental use.
The researchers also carried out five-axis CNC machining trials to produce the threaded implant shape. Some difficulties were encountered in moving the cutting tool along curved surfaces, prompting further optimisation.
Despite this, the team has described the fabrication approach as reproducible and potentially suitable for scale-up.
Published in Materials Letters, the research also reflects efforts to develop indigenous biomedical technologies that could eventually support more accessible and high-performance dental care in India.
