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New imaging technique for faster andmore accurate detection of cavities
Junji Tagami

work has generated
Q Youra significant technologicaladvance in detecting cavities.
Please tell us about thisnew technology.

A: The method we employ is called sweptsource optical coherence tomography (SS-OCT),
which uses high-speed frequency swept-laser
light from a near-infrared laser. The light isprojected at the occlusal surface of the toothand scanned across its proximal surface. Twodimensional images from below the toothsurface are generated by detecting the backscattered laser beam signal, which is digitizedover a time scale.

methods are currently
Q Whatused to detect cavities, and how

Executive Director at TMDU / Executive Vice President of Education andInternational Student Exchange / Professor of Cariology and Operative Dentistry

Dr. Tagami completed his dental and graduate school at TMDU, where he received
his DDS and PhD. He became Adjunct Assistant Professor at the Medical College ofGeorgia at Augusta University, and in 1994, assumed the post of Professor and Chairmanof the Department of Operative Dentistry at Ohu University. He returned to TMDU in 1995
as Professor and Chairman of Cariology and Operative Dentistry. Dr. Tagami became
Executive Director and Executive Vice President in 2014.

in several ways. First, cavities were detected
at an earlier stage with SS-OCT than withradiographs. Also, SS-OCT detected cavities
in areas that may be difficult to reach using
radiographs. Finally, SS-OCT appears to provide
more reliable and accurate images than bitewing radiographs. In addition to these differences, SS-OCT images can be collected in realtime, enabling on-site diagnosis in a dental
clinic.

is the new method superior?

A: These days, oral health professionals typically use radiographs to detect cavities thatare not visible to the naked eye. However,cavitated enamel lesions and dentin caries
that comprise cavities can be difficult todetect on radiographic images, especially atthe early stages. Our study has shown thatimages generated using SS-OCT are better
than radiographic images for detecting cavities

will the new methodQ How
help patients with cavities?
A: Earlier detection of cavities using SS-OCT
would allow the cavity to be treated when it issmaller, rather than detecting it later when thecavity could be larger and require moreextensive and invasive treatment. This could
reduce the pain experienced by the patient,which is associated with more complex dentalprocedures. Moreover, SS-OCT imaging does
not require any radiation, so it can be usedsafely for dental diagnosis on patients such as
pregnant woman and young children.

us about any
Q Tellfurther improvements to theSS-OCT technique.

A: We already saw an improvement in cavitydetection using two-dimensional imaging.
Obtaining three-dimensional images in realtime will further improve detection of earlystage cavities and cavities in areas that may bedifficult to reach using X-rays. Our goal is toimprove technology that can be used in dental
offices, and this research is important in
improving overall oral care.

J. Biophotonics, doi: 10.1002/jbio.201200210

Occlusal view (left) and SS-OCT image (right) of lower first and second molars
The SS-OCT image was obtainedby scanning along the dottedyellow line shown in the lefthand image. SS-OCT reveals slightdemineralization at the firstmolar (red arrow) and enamel
caries at the second molar (bluearrow).

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