Wednesday, February 03, 2010

Dental Did You Know: Dental Radiation and Airport Scanners?

Hi everyone,

Ok, it seems that everyone is worked up about the potential for damage from these new airport backscatter radiation scanners. (Which also brings up the topic of radiation doses from dental radiographs). On occasion, certain patients will decline radiographs because they think the doses they are receiving are large.

To clear the record, this chart from the Health Physics Society ( gives us the basis of where a dental radiograph is compared to other medical xray procedures:

(Dosage in millirem (mrem))

Skull (lateral): 1
Chest (PA): 2
Skull (PA or AP): 3
Chest (lateral): 4
Chest (PA and lateral): 6
Limbs and joints: 6
Thoracic spine (AP): 40
Thoracic spine (lateral): 30
Lumbar spine (AP): 70
Lumbar spine (lateral): 30
Abdomen (AP): 70
Abdomen: 53
Pelvis (AP): 70
Pelvis or hips: 83
Bitewing dental film: 0.4

As you can see, dental films are *way* down the scale in terms of dosage and provide information that is beneficial to the patient in term of detecting potentially large cavities in between teeth and other pathological conditions.

As another basis of comparison, most people don't know they are getting a dose of radiation from the environment: house, lawn, park, work, airplane, office etc. This dose is in the range of 300 millirem per year. The new airport scanners are 5-10 microrem (not millirem), therefore going through these scanners are about 1/50th of a dental radiograph and 1/30000 background radiation.

Now, any radiation dose is not good for you, but we as health practitioners have to balance out the consequences of not taking a picture vs. taking the pictures. The odds ratios almost always favour taking a radiograph in order to help the patient overall.

As for the airport scanners, I would personally be more worried about crossing the street in traffic.



Source: Stabin M, Doses from Medical Radiation Sources, Health Physics Society, Dec 18, 2009, Read on Feb 3/10,

Hans Skariah, B.Sc., DMD
Promenade Court Dental Health Group in Mississauga
2233 Hurontario St., Mississauga, ON, Canada
(1/2 km north of the QEW in the Dome Building)
(905) 273-7100