Researchers from the University of Nevada Las Vegas have developed a device they call the “Tooth Cracker 5000”, which can extract 80% of the stem cells that are available in the dental pulp.
Tooth root pulp is home to two types of prized stem cells. The first, pluripotent stem cells, which have the ability to become any cell in the organism from which they’re drawn. The second is the multipotent stem cells that can transform into specific types of cells within that organism.
Knowing where to find these cells was one thing. Recovering them, the researchers knew, would be another.
Common methods for extracting root pulp involve drilling into, removing the top of, or shattering the tooth. Each method has its detriments, Dr. Mah said, all of which lead to a low stem-cell recovery rate: damaging heat from drilling, corrosive elements in the water teeth are rinsed in, contaminating enamel particulates, and more. So the researchers sought to discover how to extract pulp in a manner that consistently produced a higher yield.
“Initially, the answer seemed simple: crack the tooth in half like a nut and remove the pulp,” Dr. Mah said.
Unfortunately, teeth have irregular surfaces and non-uniform shapes, so cracking teeth usually produces the same shattering effect as a hammer, thereby reducing the number of viable stem cells.
Happy Ghag, then a dental student working with Dr. Mah and Kingsley on the project, thought he might have solution to the dilemma. He approached Mohamed Trabia (UNLV Howard R. Hughes College of Engineering’s associate dean for research, graduate studies, and computing) and Brendan O’Toole (Mendenhall Innovation Program director and mechanical engineering researcher) to discuss fracture analysis.
“Happy had reviewed fracture mechanics literature and decided on a technique that scored the tooth to enable a clean break, similar to the process for custom-cut glass,” O’Toole said. After a few discussions, some of Engineering’s personnel helped Ghag fabricate the device.
The completed instrument, which the research team facetiously dubbed the “Tooth Cracker 5000,” uses a clamp to hold a tooth in position for a cutting tool to score the surface and a blade to crack it. The result: a perfectly halved tooth, with immediate access to undamaged and uncontaminated root pulp.
For O’Toole, this was just another successful collaboration between the two units, as Mechanical Engineering had been interacting with the School of Dental Medicine’s orthodontic program for a few years.
“Orthodontics, by definition, is a bioengineering topic,” O’Toole said. “They design and place mechanisms in people’s mouths that help move teeth into optimum position. The interaction between our departments makes a lot of sense.”
With the Tooth Cracker 5000 complete, Dr. Mah and Kingsley tested the fracture rate of 25 teeth, achieving a 100 percent rate of success. The fracture idea and design prototype had worked perfectly.