Re: dental x-ray web information

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

If you isolate each sentence of Dr. Weil's response to "Are 
Dental X rays Safe?", then much of it is correct.  The 
problem is that it does not fit together.
The radiation dose from typical dental radiography, 
performed using state-of-the-art equipment and techniques, 
is equivalent to a few days of natural background.  The 
exact amount depends, of course, on the number and type of 
exposures made.  There is no evidence of any harm from 
these doses; neither is there evidence of absence of harm.  
The risk, if any, must be infinitesimally small.
Early radiologists have shown an increased incidence of 
leukemia.  However, those entering practice since the 
1930s, when radiation protection standards were introduced, 
show no evidence of ill effects.
It is true that diagnostic exposure, medical or dental, 
should be limited to specific clinically-indicated 
procedures, based on findings from history and physical 
examination.  There is no recommended time interval for 
repeat exams for all comers.
Tubehead leakage and beam filtration are only two of many 
factors that should be optimized for maximum efficiency of 
diagnostic x rays: maximum information at minimum dose.
There is no conclusive evidence that antioxidants have any 
effect in protecting against the cancer risk from small 
doses of radiation.

***********************************************************
S. Julian Gibbs, DDS, PhD               Voice: 615-322-3190
Professor of Radiology                    FAX: 615-322-3764 
Dept. of Radiology & Radiological Sciences
Vanderbilt University Medical Center
Nashville TN 37232-2670 Email:s.julian.gibbs@Vanderbilt.Edu