Posts for tag: x-rays
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.
X-rays are such a routine part of dental care that it's easy to overlook how much this technology has revolutionized detecting and treating tooth decay. It's safe to say x-rays have helped save hundreds of millions of teeth over the last hundred years.
Thanks to its unique properties these invisible electro-magnetic waves give us precise images of the interior structure of teeth and gums. It's so precise that we can clearly detect even a small spot of softened, decayed tooth structure on an exposed x-ray film, often before it becomes visible to the naked eye. As a result, we can begin treating the decay earlier, minimizing the damage and increasing the chances for preserving the tooth.
There are a variety of ways we can utilize x-ray technology in diagnosing dental problems. The one, though, that's used the most is called the bitewing. The name comes from wing-like tabs extending out from a thin frame holding a segment of unexposed film. A technician places the frame inside the patient's mouth with the film on the tongue side of the teeth, and has them bite down on the tabs to hold the frame still. They then aim a camera at the patient's outer cheek, which then emits a very short burst of x-ray energy to expose the film.
Bitewings are popular because they give a full view of the back and side teeth, where decay is often hard to detect, with very little radiation exposure to the patient. And as x-ray technology has progressed over the years with digital processing and more efficient equipment, we can acquire sharper images with even less exposure. We've also developed standard protocols for when and how often we perform x-rays, so that we're getting the most diagnostic benefit for the least amount of exposure time.
Those few minutes getting an x-ray may seem routine, but the benefits to your dental health are truly amazing. The bitewing and other forms of x-rays play a huge role in helping us keep your teeth as healthy as they possibly can.
If you would like more information on x-ray diagnostics, 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 “Bitewing 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.”
It's difficult to measure how x-ray imaging has transformed dentistry since its use became prominent a half century ago. As equipment and methods standardized, the technology revolutionized the way we diagnose tooth decay and other mouth-related issues.
One of the more useful of these methods is called the bitewing x-ray. The term comes from the shape of the device a patient holds between their teeth with the film attached on the side toward their tongue. We direct the x-ray beam to the outside of the patient's cheek, where it passes through the teeth to expose on the film. Its particular design provides clearer images since the patient's bite helps keep the film still and distortion-free, making it easier to view signs of early tooth decay.
Bitewing x-rays usually consist of four films, two on either side of the mouth, necessary to capture all of the teeth (children with smaller jaws, however, often only require one film per side). How frequently they're conducted depends on a number of factors, including the patient's age: children or young adolescents are usually filmed more frequently than adults, usually every six to twelve months. Frequency also depends on a patient's particular decay risk — the higher the risk the more frequent the x-ray.
Regardless of how often they're performed, a similar application principle applies with bitewing x-rays as with any other radiological method: As Low As Reasonably Achievable (ALARA). With the ALARA principle in other words, we're looking for that sweet spot where we're able to detect the earliest stages of dental disease with the least amount of radiation exposure.
Bitewings fit this principle well: a patient receives only a fraction of the radiation exposure from a four-film bitewing as they do from a daily dose of environmental radiation. Factor in new digital technology that reduces exposure rates and bitewings pose virtually no health risk to patients, especially if conducted in a prudent manner.
The benefits are well worth it. Thanks to bitewing x-rays we may be able to diagnose decay early and stop it before it causes you or your family member extensive tooth damage.