In Search of a Pale Amber Panacea Share This OHSU Content

Harry Davis, PhD (left) and John Mitchell, PhD, load a sample of bioactive glass into a scanning electron microscope.

Harry Davis, PhD (left) and John Mitchell, PhD, load a sample of bioactive glass into a scanning electron microscope.

OCTRI pilot award recipient brings chemistry background to dental treatments.

In Portland, Oregon, Harry Davis, Ph.D., produces small batches of pale amber and dark brown solutions in search of a better mouthfeel than large-scale commercial offerings—but he’s no brewmaster. Rather, Davis is a chemist at Oregon Health & Science University’s School of Dentistry and the recipient of a Career Development Pilot Project award from the Oregon Clinical and Translational Research Institute (OCTRI). He explores how to make many kinds of dental treatment more effective and comfortable—using finely ground glass.

Silicate-based bioactive glasses (BAGs) have been used for more than 30 years, but Davis has found a way to make types that have far greater surface area—and thus serve as far better scaffolds for bioactivity. They could, for instance, help bone regenerate around a BAG-coated titanium implant in a fractured jaw, or help prevent tooth surfaces from decalcifying around orthodontic appliances when kids don’t brush well. Even at their most mundane, better BAGs could more effectively fill a worn tooth’s exposed dentin tubules, outperforming current toothpastes that suppress sensitivity.

“I almost feel like I’d completed my career before I came here,” said Davis. After many years as a research chemist and professor, Davis found himself hired “out of the blue” by the School of Dentistry in 2006 to produce BAG starting materials that were simply more cost-efficient than commercial offerings. He went further, however, and used this material to formulate new BAGs that were previously unavailable. Davis and his colleague, John Mitchell, Ph.D., a professor in the school’s Department of Biomaterials & Biomechanics, suspected that surface area would be increased as well. However, they were astounded when analyses indicated greater than 100 times the surface areas of commercially available BAG. This was a discovery that could make a real difference, for both routine dental care and more extreme dental trauma.

“A great thing about this work is that the supplies are not expensive,” said Davis. However, analyzing samples can be very costly. This presented a dilemma. At a later stage of development, the work might attract federal and/or industry funding—but how could Davis and Mitchell fund the early stages that would confirm the discovery’s potential?

Fortunately, Mitchell was aware that OCTRI’s Pilot Project awards and suggested that Davis apply.  As a result, Davis received a one-year, $15,000 award. “When the results came out, I was excited to see my name,” Davis laughed, “but it was matched with someone else’s study!” The mix-up was quickly corrected, and both parties found they were indeed funded.

One condition of the award was that Davis find a mentor, despite his extensive C.V. This posed no problem, however. Although they are contemporaries, Davis already looked to Mitchell for expertise in guiding research toward clinical needs. “His familiarity with that is much greater than mine,” explained Davis. “He and Jack [Ferracane, Ph.D., chair of the department] are my go-to people for deciding which direction to take.”

At the half-way point in his year-long study, Davis is halfway through his one-year award period and is preparing to carry out in vitro tests to determine how samples interact with simulated body fluids. He has embodied OCTRI’s precept of collaboration among institutions by drawing on his extensive teaching connections: He uses analytical tools from nearby Portland State University that suffice for the current stage of his research and help make the most of his funding.

However, Davis harbors no illusions about what’s to come. Moving to clinical trials with human volunteers—even for something as relatively innocuous as orthodontic brackets (“braces”) will require far more resources—and thus, far more funding. He credits OCTRI for allowing him to prepare to compete for larger grants. “Funding is often too focused on end products,” said Davis, “but an award like this gives you a chance to explore, discover and figure out what you’ve got.”