Posted December 5, 2018

Growing teeth: Researchers regenerate dental tissue

The collaborative research between the Kornberg School of Dentistry and the College of Engineering uses stem cells to regrow the pulp-dentin complex that makes up the center of a tooth.

Two scientists working in a lab
Photography By: 
Ryan S. Brandenberg
Associate Professor of Endodontology Maobin Yang, center, works in the Regenerative Health Research Laboratory at the Kornberg School of Dentistry with assistance from visiting research scholar Yu Du, left.

Undergoing a root canal may someday be a more pleasant experience, thanks to the work of a pair of researchers at Temple.

Associate Professor of Endodontology Maobin Yang, director of the Regenerative Health Research Laboratory at the Kornberg School of Dentistry, and Professor and Department Chair of Bioengineering Peter Lelkes have been collaborating on the research for three years. Yang and Lelkes’ work focuses on using dental stem cells to regenerate the pulp tissue (including blood vessels and nerves) and dentin tissue that comprises the inside of a tooth.

“These two tissues come from a similar region and have a close relationship to each other. They make up the pulp-dentin complex,” Yang explained. “If dentin decay is not that severe, the pulp can generate new dentin to repair it—all this happens naturally.

“But when we see patients, most have the pulp infected, so the nerve has to be taken out,” he continued. “The root canal is then empty, so we currently fill up the root canal with inert treatment.”

But Yang wanted to find a better treatment than the inert substance typically used in root canals. So he began to research the use of stem cells in conjunction with a small scaffold to simultaneously regenerate both tissues that form the pulp-dentin complex.

In generating the tissue using stem cells, there’s one major problem. “When you put the components into the canal, they don’t have spatial control, so they don’t know where to grow the pulp and the dentin—the dentin outside and the pulp inside. So we need structure.”

That’s where Lelkes, a Laura H. Carnell Professor, came in: He worked with Yang to develop a bioengineered two-sided scaffolding to guide the tissue growth.

This is one of the great cases when he says, ‘Here, I have a clinical problem, let’s try to find an engineering solution to this problem.'"
-- Peter Lelkes, Department Chair, Bioengineering

“The beauty of the system is that we have shown in vitro [test tube] that we can engineer a two-sided scaffold, and can guide the stem cells to differentiate into both pulp cells and dentin, producing odontoblasts that will eventually repair the root canal. We—our smart scaffold—can do this differentially with great efficacy.”

Yang and Lelkes’ partnership was born out of a friendship that occurred by happenstance: When Yang arrived at Temple six years ago, he initially worked out of a lab in Lelkes’ department and found a mentor and friend in Lelkes. So when he needed bioengineering assistance in his research, he turned to Lelkes.

“This is one of the great cases when he says, ‘Here, I have a clinical problem, let’s try to find an engineering solution to this problem,’” Lelkes said.

The pair recently published their findings in the journal Tissue Engineering

Yang said growing full teeth is still a bit distant in the research, because the various materials that make up teeth are complex and differ in their components. He said most research similar to his and Lelkes’ focuses on regenerating parts of the tooth—and regenerating the nerve and dentin, as they are, is particularly valuable, as root canal treatment is such a common procedure.

The next step for the researchers is to test the tissue growth technique in animal models.

“I believe in the next 10 years, or even sooner, when patients come to the endodontist for a root canal treatment, we will be able to provide an alternative, equivalent or even better treatment modality, which is to regrow the nerves and the blood vessels and to grow new pulp back into your tooth, instead of using inert material,” Yang said. “With investments and with lots of research, I believe that we will get there soon.”