Dental radiology; xeroradiography

["Gibbs, S Julian" <s.julian.gibbs@vanderbilt.edu>]

The arguments that newer faster dental films produce inferior 

images are based on the same sort of reasoning as the LNT 

hypothesis.  Conversely, several well-conducted studies have 

compared performance of D-speed films (the standard since the 

1950s) with E-speed, for a variety of diagnostic tasks.  All show 

no significant differences.  F-speed film is new; studies are under 

way but not finished.  The costs of all three film types are 

comparable and in most cases identical.  Thus there is nothing to 

lose from use of faster films, and there may be some gain.  I think 

we all agree that if we can reduce unnecessary radiation exposure 

at no cost, then we should do so.  This has nothing to do with LNT. 

It is just common sense.

Xeroradiography fell into disfavor for mammorgraphy (or any other 

diagnostic imaging) largely because the equipment was so 

unreliable.  The standard joke in radiology departments was that if 

one wants to use xeroradiography, one must purchase at least two 

units in order to have a 50% chance that one would be working when 

needed.  The manufacturer seemed unable to correct the problems. 

The xero images were good, but modern screen-film images are 

equally suitable for the diagnostic task.

We must remember that for both dental radiography and mammography 

image quality is judged on the basis of diagnostic information, not 

esthetic quality.



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S. Julian Gibbs, DDS, PhD               Voice: 615-322-1477

Professor, Emeritus

Dept. of Radiology & Radiological Sciences

Vanderbilt University Medical Center     Home: 615-356-3615

209 Oxford House        Email:s.julian.gibbs@vanderbilt.edu

Nashville TN 37232-4245     or alias:j.gibbs@vanderbilt.edu

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