U of S dentistry students win national research competition with new mercury-free material for filling teeth

Research by three students in the U of S College of Dentistry may lead to a new mercury-free material or amalgam for filling teeth.

"Amalgam is tried, tested and true, it's been used for many years, but there is such a negative public perception of mercury-based amalgams even though there are no harmful side effects," said Anapaula Campos, a fourth-year dentistry student.

With the help Dr. Azita Zerehgar, assistant professor of pediatric dentistry, and Assem Hedayat, assistant professor of dental materials, the group—including Kellyana Quattrini and Jenna Schmitt—set out to see if they could come up with a material that was long lasting and had amalgam's strength but replaces the mercury found in traditional amalgams.

Using Hedayat's expertise in materials science, they came up with potential mercury replacements.

"We helped him figure out what kind of material we needed and he came back to us with a silver solution and a ceramic nanoparticles. We then had to figure out what the right mixture and consistency were that would work for a filling."

With that determined, the students went to the college's tooth bank to get teeth on which to test their new material, using the standard dental filling practice. Once the teeth were filled, they were repeatedly immersed in hot and cold water to simulate the oral environment.

The tested teeth were then cross-sectioned and examined under an electron microscope. What the images revealed was surprising to the research team.

"The cross section image showed that the (new) material was a closer fit in the filling. There were no gaps showing between the fillings and the teeth compared to traditional amalgam which does show gaps along the margin of the filling," she said.

With these encouraging results, the group presented their findings at the college's research competition, which they won. They then presented their project at the national dental college competition against the other nine dental schools in Canada and placed first.

The first-place prize was a trip to San Antonio, Texas, to attend the American Dental Association's 2014 conference as international guests.

"Obviously there is more testing to do. We need to test strength, bio-compatability, corrosion and wear. It's a long process and we have applied for a research grant to keep the research going, but it has been a great experience."


For more information, contact:

Jennifer Thoma

Media Relations

University of Saskatchewan


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