A titanium dental implant coated with proteins that induce
bone formation is a key advancement in treating tooth loss due to gum disease,
researchers say.
In laboratory tests, Medical College of Georgia researchers applied a protein that directs stem cells into bone-forming cells onto a dental implant. The result was a nearly complete regeneration of lost tissues, said Dr. Ulf Wikesjö, MCG professor of periodontics.
Tissue loss including bone is a common result of gum disease.
Dr. Wikesjö, who came to MCG this year from Temple University in Philadelphia, is researching wound-healing and tissue regeneration with a $1.4 million grant from Nobel Biocare, a leading manufacturer of dental implants and equipment. Finding the key to regeneration is like putting the pieces of a puzzle together, he said.
“For the past 20 years, there has been a quest to regenerate tissues around teeth that are lost due to periodontal disease,” he said. “I’ve looked at multiple approaches to achieve regeneration, including bone grafts, root-conditioning and membrane devices for directed tissue growth, all resulting in some regeneration. We had to look at the commonalities among these treatments.”
Dr. Wikesjö and his colleagues found that regeneration requires a stable wound and space for the regenerated tissue to grow during the first stages of healing.
“If these components are in place, regeneration of the
tissues around the tooth may occur within a week or two,” he said. “After that,
it’s a matter of the wound maturing – going through the various stages of
healing that we’re already familiar with.”
By experimenting with treatments and discerning their effect on healing bone defects, they identified some that actually hindered tissue regeneration. Some of those are considered state of the art and used in clinics today.
“Some biomaterials like hydroxyapatite particles, which are chemically similar to the mineral component of bone, may actually interfere with regeneration,” Dr. Wikesjö said. “They may not resorb quickly enough and may block the space for new tissue to grow into.”
The information helped researchers narrow down
possible treatments to the use of proteins that direct stem cells into
bone-forming cells. The proteins were implanted around teeth and implants, but
around teeth, the proteins caused gum cells to attack and destroy part of the
tooth. The result with a coated implant was much better.
“There was almost complete regeneration,” Dr. Wikesjö said. “The result so far is that the implant generates its own bone that will bond with existing bone in the gums.”
The next step is clinical trials of the implant.
“In some cases, the protein may rapidly release from the implant, and other times, there appears to be a more gradual release,” Dr. Wikesjö said. “We need to find out what factors cause that. In the end, we may not need to use much protein to make the implant effective. Those are things we’re looking at now.”
-Jennifer Hilliard