Dental X-rays
Dental x-rays are a vital tool in the diagnosis of dental diseases such as cancer, bone infections, abscesses, cysts, and decay. Rays that can penetrate an object, revealing the contents within, were discovered by Wilheim Roentgen in 1895.[1]
Radiation is known to be accumulative in the cells of our bodies. How much radiation do we as dental consumers get from a regular set of x-rays during a routine dental visit? This and many more questions should be asked and understood by each dental care consumer. This article will address these and other issues that dental consumers should be made aware of.
History of dental x-rays
Dental x-rays began to be used by Dr. Otto Walkoff in Germany, 1896 [2]. The first dental x-ray was used by Dr. Edmund Kells and in 1856. He used glass plates to capture the desired image. The first dental x-ray film was used by Dr. Frank Vanwoert. Dental x-ray equipment and procedures have progressed over time. Glass plates, used by Kells in 1856 were changed to film, used by Vanwoert. Today X-ray film has been replaced by a digital form reducing almost eliminating exposure to unsafe doses of dental radiation.
Amount of radiation from dental x-rays
As a clinician, I am asked a variety of questions regarding the amount of radiation received from our dental x-rays. X-rays come from a variety of sources and are accumulative throughout our lifetime. A unit called a “rem” is used to measure radiation. A rem is a large unit, much like a mile is a large unit of length, so we usually use a millirem (mrem) instead, much as you would measure in inches instead of miles for most purposes. (It takes 1000 mrem to equal one rem.)[3] A typical dental x-ray image exposes you to only about 2 or 3 mrem. The National Council on Radiation Protection (NCRP) says that the average resident of the U.S. receives about 360 mrem every year from background sources. This comes from outer space, radioactive materials in the earth, and small amounts of radioactive material in most foods we consume.3
Just for your information, “Some typical sources that may expose you to radiation also include smoke detectors (less than 1 mrem per year), living in a brick house instead of a wood one (about 10 mrem per year due to radioactive materials in the masonry), cooking with natural gas (about 10 mrem per year from radon gas in the natural gas supply), reading a book for 3 hours per day (about 1 mrem per year due to small amounts of radioactive materials in the wood used to make the paper), and even from flying in an airplane (about 5 mrem for one cross-country flight because of the increased altitude.) In fact, you receive about 2 mrem per year from sleeping next to someone! This is because all of us have very small amounts of naturally occurring radioactive materials in our bodies. [4]
Why do I need a dental x-ray?
At times dental consumers wonder, “x-rays again”. It is important to be aware of the advantages of having regular dental x-rays taken.
Advantages of Dental x-rays
Digital radiographs reveal small hidden areas of decay between teeth or below existing restorations (fillings), bone infections, gum (periodontal) disease, abscesses or cysts, developmental abnormalities and tumors that cannot be detected with only a visual dental examination.
Digital radiographs can be viewed instantly on any computer screen, manipulated to enhance contrast and detail, and transmitted electronically to specialists without quality loss.
Early detection and treatment of dental problems can save time, money and discomfort.[5]
Digital micro-storage technology allows greater data storage capacity on small, space-saving drives.
Dental digital radiographs eliminate chemical processing and disposal of hazardous wastes and lead foil, thereby presenting a "greener" and eco-friendly alternative.
Digital radiographs can be transferred easily to other dentists with compatible computer technology, or photo printed for dentists without compatible technology.
Digital sensors and PSP (photostimulable phosphor) plates are more sensitive to X-radiation and require 50 to 80 percent less radiation than film. This technology adheres to the ALARA (As Low As Reasonably Achievable) principle, which promotes radiation safety.
Digital radiograph features, including contrasting, colorizing, 3-D, sharpness, flip, zoom, etc., assist in detection and interpretation, which in turn assist in the diagnosis and patient education. Digital images of problem areas can be transferred and enhanced on a computer screen next to the patient's chair.
Disadvantages of dental x-ray
Are there disadvantages to having routine dental x-rays? There is always a risk involved in taking any type of x-ray especially to the physically compromised. However, the risk involved with digital dental x-rays outweighs the disadvantages.
Digital dental x-rays are a necessary and vital tool for the diagnosis and care of dental disease. Exposure to digital x-rays is now so minimal that even those individuals that are at risk can safely take care of their dental needs.
Tess Hulet RDH, MHSM
[1] Assmus, Alexi. Early History of x Rays. Summer 1995 P24. www.slac.stanford.edu/pubs/beamline/25/2/25-2-assmus.pdf.
[2] Singer, Steven R. DDS. The History of OralRadiology Part II. srs2@columbia.edu
[3] http://www.physics.isu.edu/radinf/dental.htm
[4] http://www.physics.isu.edu/radinf/dental.htm
[5] Rondon Nayda, Nosti John, DMD. Digital Dental Radiography: Zooming in on the Future of Dental Imaging. http://www.yourdentistryguide.com/digital-radiography/