Amin RizkallaThree-dimensional solutions

By Ciara Parsons, BA’15

Schulich Dentistry researchers are developing novel applications of three-dimensional (3D) printing for use in cranio-facial reconstruction.

Amin Rizkalla, PhD, PEng, is the principal investigator and he is working with a team of people, including Yara Hosein, PhD, Drs. Joe Armstrong and Henry Lapointe, as well as David Holdsworth, PhD, to determine how 3D printing can be utilized to develop porous titanium constructs for craniofacial reconstruction.

They are hoping that their research will help to solve a large problem in current craniofacial reconstruction methods.

Because solid metal implants used to repair defects in the skull and face are mechanically stiffer than human bones they create stress shielding, a known adverse reaction.

Stress shielding prevents the remodelling process and decreases the amount of loading on the bone, which serves to weaken it. In some cases, when there is an absence of stress on the bone, necessary regeneration does not occur, and the implant will loosen and fail.

Working closely with clinicians, Rizkalla has set out to design a titanium metal device that is porous and has a bone-like firmness. The hope is that craniofacial reconstruction implants can be optimized and avoid issues associated with stress shielding.

“We have looked to 3D metal printing for this project because conventional manufacturing limits the fabrication of complex geometries, such as those expected in our device. 3D printing allows more flexibility in terms of design for customized medical and dental devices,” said Hosein, a postdoctoral fellow in Rizkalla’s lab.

The research project is still in its early phases, however, preliminary titanium 3D printed constructs are being designed using computer-aided design (CAD) software at Western University.

The final prototypes will be 3D printed at Western University’s Additive Design in Surgical Solutions (ADEISS) Centre. This multi-million dollar facility is one of the only of its kind in Canada and stands to put London on the map as a North American leader in 3D printed prosthetics and surgical implants.

Rizkalla says the ability to design custom constructs and receive them in as little 12 hours is a huge advantage to the experimentation phase of this research.

As personalized medicine takes a more prominent role in health care innovation, the success of 3D printing in dentistry-focused implants could make craniofacial reconstruction methods more individualized and patient-specific.

Hosein expressed that one of the issues with titanium implants occur because they are not an ideal ‘match’ to the patient.

“Many of the implants used clinically for these craniofacial reconstructive surgeries are ‘off the shelf’,” said Hosein. “With our technology, once we are able to show that we can develop implants that have optimal stiffness, we can also apply patient-specific designs to these implants.”

Since many Canadians are without private dental coverage, cost can be a barrier to many in need of dental or oral health care services. The team believes that, if successful, 3D printing may be able to help ease some of the costs associated with dentistry and specialized services related to oral health care.

“On one build plate, which is what we use to print constructs, we can print dozens of individual implants. If you can fill the build plate, the cost of each device will be reduced significantly. There will also be less overhead fees from manufacturing,” said Rizkalla.

The impact of this research stands to re-shape the surgical processes of craniofacial reconstruction for better patient outcomes, and has the potential to impact other facets of dentistry and orthopedics affected by stress shielding issues.

Dr. Armstrong, an oral and maxillofacial surgeon, believes the application of a porous titanium construct can also promote bone growth and act as a conduit for better drug delivery in the body.

Dentistry education, too, may soon be changing around the capabilities of 3D printing, once it becomes more established in the field of dental and oral health care services.

“3D printing has the potential to change the dentistry curriculum for students. In the future, they may be learning how to design 3D printed devices with CAD programs,” said Rizkalla.

The team still has much work ahead of them until they can move into clinical trials, but are motivated to discover new and novel approaches to craniofacial reconstruction and see their research translated into real-life applications.