Boning Up

Implant a Major Advance in Treating Tooth Loss

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, MCG researchers applied a protein that directs stem cells into boneforming cells onto a dental implant. The result was a nearly complete regeneration of lost tissues, said Dr. Ulf Wikesjo, MCG professor of periodontics.

Tissue loss including bone is a common and devastating result of gum disease.

Dr. Wikesjo is researching woundhealing 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, rootconditioning and membrane devices for directed tissue growth, all resulting in some regeneration. We had to look at the commonalities among these treatments.”

Dr. Wikesjo 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 effects 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. Wikesjo said. “They may not resorb quickly enough and may block the space for new tissue to grow into.”

The information helped researchers narrow possible treatments to the use of proteins that direct stem cells into boneforming 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. Wikesjo said. “The result so far is that the implant generates its own bone that will bond with existing bone in the jaws.” The next step is clinical trials of the implant, which Dr. Wikesjo hopes to start soon.

“In some cases, the protein may rapidly release from the implant, and other times, there appears to be a more gradual release,” Dr. Wikesjo 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

 

 

The Medical College of Georgia is the state’s health sciences university with a tripartite mission of education, research and patient care.