Posts for tag: x-rays
X-ray imaging is such an intricate part of dentistry, we usually don't think twice about it. Without it, though, the fight against dental disease would be much harder.
At the same time, we can't forget that x-rays are a form of electromagnetic radiation that can penetrate human tissue. It's that very quality and the difference in the absorption rate between denser bone and teeth and softer diseased tissue that makes disease diagnosis possible.
But this same penetrative power can potentially harm the tissues it passes through. For that reason when practicing any form of x-ray diagnostics, dentists follow a principle known as ALARA, an acronym for "As Low As Reasonably Achievable." In lay terms ALARA means getting the most benefit from x-rays that we can with the lowest dose and exposure time possible.
While practicing ALARA with x-rays is important for patients of any age, it's especially so for children who are more sensitive to radiological energy given their smaller size and anatomy. We can't use the same settings, dosages or exposure times with them as with an adult.
To protect children, dentists have developed techniques and protocols that lessen their exposure time and rate, while still providing usable images for diagnosing disease. The bitewing is a good example of safe and effective pediatric x-ray imaging.
A bitewing is a plastic device holding exposable film that patients bite down on and hold in their mouth while x-raying. The x-rays pass through the teeth and gums and expose the film behind them on the bitewing. Using a bitewing we can capture a set of two to four radiographs to give us a comprehensive view of the back teeth, while exposing the child less radiation than they normally receive daily from background environmental sources.
This and other advances in equipment and digital imaging greatly reduce the amount of radiation patients receive during x-rays. If, though, you're still concerned about your child's x-ray exposure, talk with your dentist who can explain in more detail the x-ray safety protocols they follow. Just like you, they want your child to be as safe as possible while still benefiting from the diagnostic power of x-rays.
If you would like more information on safety precautions using x-rays with children, please contact us or schedule an appointment for a consultation. You can also learn more about this topic by reading the Dear Doctor magazine article “X-Ray Safety for Children.”
One of the most widely used forms of dental imaging is the bitewing x-ray. So called because of the shape of the device that holds the exposable film a patient clenches between their back teeth, the bitewing x-ray is an effective means for detecting the earliest stages of tooth decay.
These early signs are small lesions on a tooth surface caused by mineral loss in the enamel. While we can identify them on front teeth through visual examination or bright lighting, they’re nearly impossible to see on the biting surfaces of back teeth. The bitewing x-ray solves this problem.
During the procedure, a narrow beam of x-rays is directed at the back teeth area. Since X-rays can transmit through solid matter, they pass through the teeth and gums to expose the film attached to the bitewing assembly.
X-rays pass through matter at different rates depending on the density of the tissue — a slower rate for harder tissues like teeth and bone and a faster rate for soft tissues like the gums. As a result, x-rays through teeth expose less of the film and appear as a lighter image than the gums. This difference is so precise even a tooth’s softer dentin appears slighter darker than its harder outer enamel.
This precision helps us identify decay lesions. Because the lesions on the enamel are less dense than the normal enamel, they’ll appear as dark spots. By detecting them at this stage we have a better chance for reversing the effects of decay or at least minimizing damage that’s already occurred.
Because x-rays emit radiation, there’s a natural concern about over-exposure and we go to great lengths to reduce it. Children may undergo a bitewing x-ray twice a year for developing teeth, while adults with healthy teeth are typically x-rayed just once a year. Advances in digital film and other technology have also helped lower the exposure rate.
Today’s standard 4-film bitewing x-ray produces about four days worth of what we receive on average from normal background radiation, so the health risk is quite negligible. The benefit, on the other hand, is much greater — the early detection of tooth decay could ultimately save a tooth.
Radiographic (x-ray) images are an indispensible diagnostic tool in dentistry. One of the most routine and useful types of x-rays dentists take is the so-called bitewing. Here are some things you may want to know about this common diagnostic procedure.
What are bitewing x-rays?
Bitewings reveal the presence and extent of decay in the back teeth, specifically in areas where adjacent teeth touch each other. Unlike other areas of the teeth, these contacting surfaces between adjacent teeth can’t be examined visually. Bitewings can also show areas of bone loss around teeth — a sign of periodontal disease; however, they are not taken for that purpose because bitewings will not show the complete root surface that is surrounded by bone.
Why are they called that?
The name “bitewing” refers to how the film — or sensor, in the case of a digital x-ray — is positioned in the mouth: The patient bites down on a little tab or wing that holds the apparatus in place.
How often do I need them?
This is determined on a case-by-case basis, with the goal of not exposing you to any more radiation than necessary — even the minimal amount found in a series of bitewing x-rays. Your individual susceptibility to caries (tooth decay) and personal dental history will play a major role in determining how frequently you need radiographic examination — and, for that matter, how often you need to come in for routine cleanings and exams.
Are they safe?
The safety of bitewing x-rays is best illustrated with a comparison to the regular daily radiation exposure we get every day from environmental sources, which is about 0.01 millisieverts — the unit of measure we use for radiation. A series of 4 bitewing x-rays exposes you to 0.004 millisieverts of radiation — less than half of the daily exposure. Undetected tooth decay, which can spread quickly through the softer inner layers of teeth, is considered much more dangerous!
If a bitewing x-ray shows that there is tooth decay, what happens next?
If the cavity is very small, we may be able to treat it during the same appointment. If not, we will make a separate appointment to make sure it is taken care of promptly. The sooner tooth decay is treated, the better!