Jul 11, 2017 | By Benedict
Researchers at the University of North Carolina and North Carolina State University have conducted a study to evaluate two 3D printing methods, electron beam melting (EBM) and direct metal laser sintering (DMLS), for manufacturing titanium osseointegrated implants.
Titanium 3D printed osseointegrated implants can be used to improve the integration of prosthetic devices
One thing that everyone involved in 3D printing can agree on is that titanium 3D printed implants are transforming modern medicine. But beyond that obvious statement, there’s a lot of room for argument.
For example, medical and additive experts are still trying to find out what 3D printing techniques are best for producing medical implants, while competing medical device companies generally all claim that their own 3D printed designs are the most effective at repairing the body, encouraging bone regrowth, or fitting naturally and safely into their designated bodily location.
These disagreements make it especially important for independent researchers to carry out experiments on 3D printed titanium implants, and that’s exactly what researchers from two North Carolina universities have just done.
A study conducted by the two universities has shown that 3D printing can be used to customize implant surface textures and geometries to match the specific anatomy of human amputees. But perhaps most interestingly, the study tested both EBM (using an Arcam A2 3D printer) and DMLS (using an EOS M290) 3D printing techniques, finding that the techniques produced differing results.
The subject of the study was the production of titanium osseointegrated implants, medical devices upon which new bone can grow and interact.
“Osseointegrated implants transfer loads from native bone to a synthetic joint and can also function transdermally to provide a stable connection between the skeleton and the prostheses, eliminating many problems associated with socket prostheses,” the researchers wrote in their research paper. “Additive manufacturing provides a cost-effective means to create patient-specific implants and allows for customized textures for integration with bone and other tissues.”
During the study, two groups of Sprague-Dawley rats received bilateral titanium implants in their distal femurs, one group receiving EBM implants transcortically in one femur and a DMLS implant in the contralateral femur, the other receiving DMLS implants in the intramedullary canal of each femur. The rats were then studied for four weeks.
Each 3D printed implant measured 7 mm in length and 2 mm in diameter, and was made from grade 5 titanium.
Surface topography of fine-textured (left) and coarse-textured DMLS titanium implants
Interestingly, while the EBM 3D printing method can only produce a coarse textured implant, DMLS can create either a fine or coarse textured surface. Knowing this, the researchers wanted to see how the techniques affected resulting strength of bone integration, interlocking, and torque.
When the rats’ four-week period of evaluation was up, the North Carolina researchers found that the fixation strength of coarse-textured implants provided better interlocking than fine-textured implants, without affecting bone volume fraction (BV/TV) or bone-implant contact (BIC) in both rat groups.
Additionally, the researchers discovered that the coarse EBM 3D printed implants in the transcortical model demonstrated an 85 percent increase in removal torque over the fine DMLS textured implants.
They also found that the thrust load in the intramedullary model saw a 35 percent increase from fine to coarse DMLS implants.
Their conclusion? “This research indicates that coarse textured surfaces can provide a higher interface strength for titanium alloy implants than fine textured surfaces,” they wrote. Of course, that’s hardly a damning evaluation of DMLS, since the metal 3D printing technique can also produce coarse textures, but it does suggest that coarse-textured 3D printed implants are ideal in such situations.
While the North Carolina researchers recommend that “future studies should be conducted to determine the optimal roughness for implant fixation,” their research could already prove useful for medical professionals looking to utilize 3D printing to create titanium osseointegrated implants.
The research paper, titled “Osseointegration of Coarse and Fine Textured Implants Manufactured by Electron Beam Melting and Direct Metal Laser Sintering,” was published in 3D Printing and Additive Manufacturing.
Its authors were David S. Ruppert, Ola L.A. Harrysson, Denis J. Marcellin-Little, Sam Abumoussa, Laurence E. Dahners, and Paul S. Weinhold.
Posted in 3D Printing Application
Maybe you also like:
- T-Bone Cape motion control board launches on Indiegogo
- New extruder could lower costs of 3D printing cellular structures for drug testing
- New Ninja Printer Plate for consumer 3D printing
- mUVe3D releases improved Marlin firmware for all 3D printers
- Zecotek plans HD 3D display for 3D printers
- Add a smart LCD controller to your Robo3D printer
- Maker Kase: a handy cabinet for 3D printers
- Heated bed for ABS printing with the Printrbot Simple XL
- Next gen all metal 3D printer extruder from Micron
- Pico all-metal hotend 100% funded in 48 hours, B3 announces Stretch Goal
- Create it REAL announces first 3D printing Real Time Processor
- A larger and more powerful 3D printer extruder on Kickstarter
3Ders.org provides the latest news about 3D printing technology and 3D printers. We are now seven years old and have around 1.5 million unique visitors per month.
