UMN research identifies new anti-bacterial coating for dental implants

Monday, November 10, 2014

University of Minnesota researchers have developed a novel coating for the titanium used in dental implants.

The coating kills bacteria on contact and prevents biofilm buildup that can cause infection and implant failure. Researchers hope the coating could be used in prosthetics, medical implants and medical devices used in the body. The findings were published in PLOS ONE.

The germ-fighting compound, a new antimicrobial peptide called GL13K, was derived from a human protein found in saliva and developed by Sven-Ulrik Gorr, Ph.D., study co-author and associate dean for research at the University of Minnesota School of Dentistry. The research will now move to an animal model.

“The coating kills bacteria by contact,” Gorr said. “This eliminates biofilms from forming on the coated surface of the implant.”

“This is unique because many coatings used to fight bacteria will release the antibacterial molecules into the mouth,” said co-author Dr. Conrado Aparicio, Ph.D., deputy director of the UMN Minnesota Dental Research Center for Biomaterials and Biomechanics. “Our device doesn’t do that. The antimicrobial material is actually part of the implant itself.”

The research team studied the interaction between the peptide coating and bacteria in the lab using a drip-flow biofilm reactor, which simulated human salivation.  The peptide killed most of the bacteria S. gordonii that colonize in the mouth to initiate plaque. It also destroyed P. gingivalis, bacteria that causes periodontal (gum) disease, which is a condition that can result in loss of the jawbone needed to support both natural teeth and dental implants.

According to the American Academy of Implant Dentistry, three million Americans have dental implants, a number that grows by 500,000 each year. Infection is a major cause of dental implant failure.

For patients, the findings of this study could potentially translate to safer dental implants and a reduced risk of plaque and gum disease.

The GL13K coating is stable and appears safe in the oral environment while many alternatives like traditional antibiotics or biocides cause bacterial resistance or expose the body to toxins.  
While the study is a significant discovery for dental patients, it could also lead to breakthroughs in other health fields. Aparicio and Gorr hope to adapt the peptidecoating for prosthetic limbs and implants in other parts of the body, such as hips and knees. Gorr said he would also like to modify GL13K to attack other biofilms, like the mucus that fills the lungs of people with cystic fibrosis.
“If we can prevent bacteria from attaching to dental implants, why not try it on implants used in other parts of the body?” Gorr said. “It’s very gratifying to work on something that has that much potential.”
Gorr and Aparicio both stressed the importance of collaboration in the study.
“When people come together, it makes research exciting,” Gorr said. “Every person who worked on this project has an individual specialty, and as a team, we were able to develop this device.”

That collaborative, team-oriented approach will continue in the next phase of their research. They will translate these findings into an animal model to further determine effectiveness of the coating, through the support of the U of MN’s Clinical and Translational Science Institute, and in collaboration with Joan Bechtold, Ph.D., at the Minneapolis Medical Research Foundation at Hennepin County Medical Center.

Xi Chen, DMD, Ph.D, Helmut Hirt, Ph.D., and Yuping Li, Ph.D., also contributed to this study.

Funding for this project was provided by the 3M Foundation, National Institute of Dental and Craniofacial Research at the National Institutes of Health grants R01DE017989 and R90DE023058 and the Office of the Vice President for Research at the University of Minnesota.