ADASRI examines use of cement in detecting radiation exposure

Study finds carbonated hydroxyapatite cement emits magnetic signal proportional to radiation dose received

Radiation exposure could become easier to detect, thanks to research by the American Dental Association Science & Research Institute.

Researchers from the ADASRI and National Institute of Standards and Technology studied the magnetic properties of a cement resembling the primary component of teeth, finding it could be used to measure radiation absorption.

The study, "Electron Paramagnetic Resonance Characterization of Sodium- and Carbonate-Containing Hydroxyapatite Cement," was published in August by Inorganic Chemistry, a journal of the American Chemical Society.

Using a method developed by ADA scientists Laurence Chow, Ph.D., and Shozo Takagi, Ph.D., in the 1980s, the researchers synthesized carbonated hydroxyapatite cement, which has a microstructure and composition similar to biological hydroxyapatite — the main component of calcified tissues, such as tooth enamel and bones. The cement previously received U.S. Food and Drug Administration approval as the first commercially available material to treat craniofacial defects and bone fractures.

"Because of the superior biological properties of this material, there have been — and still are — numerous research studies that focus on assessing the biological properties of the material for different existing and emerging biological applications," said Eaman Karim, Ph.D., corresponding author of the study and senior scientist with the ADASRI. "However, our focus was on investigating the paramagnetic properties of the material, which have not been studied before."

The scientists found the cement provides distinct, reproducible, stable and spectrally pure electron paramagnetic resonance signals when exposed to ionizing radiation, and the signals are proportional to the radiation dose received. This correlation means the cement could be used to measure radiation absorption.

In future studies, the ADASRI will explore how such a measurement could be used in industrial and medical settings.

"Carbonated hydroxyapatite cement could be a promising candidate for a dosimetry system, which is used to measure the amount of radiation absorbed by an individual when exposed to ionizing radiation," Dr. Karim said. "A dosimetry system using carbonated hydroxyapatite cement could have different industrial and medical applications, such as in dentists' clinics."