Using an x-ray microscope developed at Lawrence Livermore National Laboratory for the Department of Energy, researchers at the UC San Francisco School of Dentistry are probing the intricate structure of dentin, the porous material that lies under the hard enamel of teeth.
An x-ray tomographic microscope (XTM), invented by a Lawrence Livermore scientist to analyze ceramic components used in jet engines, allows the dental researchers to observe structures in the dentin as small as two micrometers -- about the size of a human cell.
Atomic force microscopy (AFM), another technology used at UCSF and Lawrence Livermore, provides an even closer view. Researchers test the strength and stiffness of dentin by pushing the very atoms and molecules apart and using the device to observe how they respond.
Researchers want to understand the structure and properties of dentin in order to find methods and materials that will create a tighter, more permanent bond between the tooth and the plastic-based fillings now used to repair most cavities.
Metal alloys create a more durable restoration than newer plastic-based and ceramic materials used for filling tooth cavities, but the ability to match the color of these materials to the natural color of a tooth makes the newer materials much more popular choices.
"We want to make the polymer (plastic-based) and ceramic materials as strong and long-lasting as metal," explains Sally J. Marshall, PhD, UCSF professor of restorative dentistry. She and Grayson W. Marshall Jr., DDS, MPH, PhD, UCSF professor of restorative dentistry, led the UCSF research team working with John H. Kinney, PhD, senior research scientist at Lawrence Livermore National Laboratory.
The team of researchers recently reported on the progress of their study at
the annual scientific meeting of the American Association for Dental Research.
The study is funded by a grant from the National Institute for Dent
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Contact: Bill Gordon
bgordon@itsa.ucsf.edu
(415) 476-7901
University of California - San Francisco
17-Mar-1998