Posts for tag: x-rays
It’s important for your child’s current and future health that we watch out for tooth decay. Taking x-rays is a critical part of staying one step ahead of this common disease.
But while x-ray imaging is commonplace, we can’t forget it’s still a form of radiation that could be potentially harmful, especially for a child whose tissues are rapidly developing. We must, therefore, carefully weigh the potential benefits against risk.
This concern has given birth to an important principle in the use of x-rays known as ALARA, an acronym for “As Low As Reasonably Achievable.” In basic terms, we want to use the lowest amount of x-ray energy for the shortest period of time to gain the most effectiveness in diagnosing tooth decay and other conditions.
A good example of this principle is a common type of radiograph known as a bitewing. The exposable x-ray film is attached to a plastic devise that looks like a wing; the patient bites down on it to hold it in place while the x-ray exposure takes place. Depending on the number of teeth in a child’s mouth, an appointment usually involves 2 to 4 films, and children are typically spaced at six months apart. Frequency of x-rays depends on your child’s tooth decay risk: lower risk, less need for frequent intervals.
Each bitewing exposes the child to 2 microsieverts, the standard unit for radiation measurement. This amount of radiation is relatively low: by contrast, we’re all exposed to 10 microsieverts of background radiation (natural radiation occurring in the environment) every day or 3,600 microsieverts annually. Even two appointments of four bitewings each year is a fraction of a percent of the background radiation we’re exposed to in the same year.
This conservative use of x-rays is well within safe parameters for children. As x-ray technology continues to advance (as with the development of digital imaging) we anticipate the exposure rate to diminish even more. Prudently used, x-rays remain one of our best tools for ensuring your child’s teeth are healthy and developing normally.
If you would like more information on the use of 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.”
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!
X-rays are an important diagnostic tool in dentistry because of their ability to penetrate and pass through body tissues. Because they penetrate at different speeds depending on tissue density (shorter and thus darker on exposed film for soft tissues, longer and lighter for hard tissues like bone or teeth), we’re able to detect decay which appear as dark areas on x-ray film.
Without x-rays, the early detection and diagnosis of dental problems would be quite difficult. But despite its obvious benefits, it’s still a form of released energy that exposes patients to a certain amount of radiation. Since the potential health risk from radiation depends on the amount released (the dosage) and for how long and often a person is exposed, we must determine if the dosage and frequency from dental x-rays is a cause for concern.
It’s a common misconception to view any radiation exposure as dangerous. The truth is, however, we’re all exposed daily to radiation from the natural environment — about 2 to 4.5 millisieverts (the dosage measurement for radiation exposure) a year, or about 10 microsieverts (one-thousandth of a millisievert) every day.
In comparison, radiation exposure from routine dental x-rays is a fraction of this if measured over time. A set of four bitewing images of the back teeth produces 4 microsieverts of radiation, less than half the average daily exposure. One of the most comprehensive x-ray sets, a full mouth series of 18-20 images using “D” speed film, results in an exposure of 85 microsieverts, equaling about a week of normal radiation exposure.
These thoroughly researched rates help demonstrate that regular dental x-rays are relatively safe. What’s more, x-ray technology has continued to advance since first used in the mid-20th Century. With innovations in film and digital processing, today’s equipment produces only 80% of the radiation exposure of earlier machines. In effect, we’ve increased our capabilities to more accurately detect and diagnose issues through x-rays, while lowering the amount of radiation exposure.
Of course, a person’s annual exposure rate may differ from others. If you have concerns for yourself or your family about x-ray radiation exposure, please feel free to discuss this with us. Our primary goal is to improve your oral health without undue risk to your health in general.
If you would like more information on x-ray diagnostics and safety, 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 Frequency and Safety.”