09.24.13
Tolou Shokuhfar, Ph.D. Image courtesy of Michigan Technological University.
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The material TiO2 has commonly been used as a white dye—commercially named E1710—in sunscreen and food products. Inorganic nanotubes are cylindrical molecules which tend to be more stable yet more malleable that better-known carbon nanotube molecules.
“Dental implants can greatly improve the lives of people who need them,” said Shokuhfar. “But there are two main issues that concern dentists: infection and separation from the bone.”
Dental implants are posts, usually made of titanium, that are surgically placed into the jawbone as bases for artificial teeth. There is a small percentage of dental implants that fail and have to be removed. Adult human mouths can play host to up 1,000 different types of bacteria, and even an adult that cleans her teeth regularly can have up to 100,000 bacteria living on each tooth surface. Bacterial infections are one serious risk to dental implants. Another obstacle to successful implants is the failure of the jawbone tissue to heal around the post. Jawbones are thin and relatively fragile, so replacing failed implants can prove difficult. Shokuhfar hopes that her nano-material will bring the failure rate to zero.
The professor’s TiO2 nanotubes have been in development for years, but Shokuhfar is now collaborating with Cortino Sukotjo, D.D.S., Ph.D., a clinical assistant professor at the University of Illinois at Chicago (UIC) College of Dentistry to develop a dental implant with a surface made from the nanotubes.
“We have done toxicity tests on the nanotubes, and not only did they not kill cells, they encouraged growth,” Shokuhfar said.
She has already demonstrated that bone cells grow more vigorously and adhere better to titanium coated with TiO2 nanotubes than to conventional titanium surfaces. That could keep more dental implants in place.
This shows a forest of titanium dioxide nanotubes etched into metallic titanium. The surface holds promise for improving the longevity of dental implants. Image courtesy of Dr. Tolou Shokuhfar. |
The nanotubes also have the ability to be laced with silver, which is an antimicrobial agent. According to an article published by Michigan Tech, Shokuhfar is conducting research with a colleague, Craig Friedrich, Ph.D., into the use of silver-doped TiO2 nanotubes in orthopedic implants such as artificial hips.
“Silver has antimicrobial properties, and we are capable of obtaining a dose that can kill microbes but would not hurt healthy cells and tissues,” Shokuhfar said.
In particular, the inclusion of silver can help prevent biofilms—vast colonies of bacteria that can cover implants and be very difficult to eradicate. A nanotextured implant surface embedded with silver nanoparticles could prevent infection for the life of the implant.
Shokuhfar and Friedrich have received a provisional patent and are working with two hospitals to further develop the technology and eventually license it. Shokuhfar expects that implants with the new nanotubular surface will be easily assimilated into the market, since titanium implants, both dental and orthopedic, have a long history.