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.”
The CAT scan is a relatively recent technique in dentistry, used to get an image of what’s happening deep within your jaws. You may be wondering what a CAT scan tells us that a conventional x-ray picture does not, and whether it is worth the extra expense to get one. And how does a CAT scan compare with a conventional x-ray in terms of radiation exposure?
CAT stands for “computer assisted tomography.” Often it’s just called a CT scan, for “computerized tomography.” The word “tomography” comes from roots meaning “slice” and “write.” Tomographic techniques take repeated two dimensional pictures, similar to repeatedly slicing through an object, and then assembles them with a computer to produce a three dimensional (3-D) image.
The latest type of CT scan used in dentistry is called CBCT, or Cone Beam Computed Tomography. The Cone Beam refers to a spiral beam of x-rays, which is used to create a series of two dimensional images from which a computer creates a 3-D image. Such an image is of great value in assessing problems and planning treatment.
Here are just a few examples of how a CBCT scan can be used. Orthodontists can see skeletal structures and developing teeth that are still inside the jawbone while planning strategies for directing the teeth in order to arrive at a better bite. Oral surgeons can find impacted or missing teeth, see their locations, and view their proximity to nerves and sinuses, assisting them in planning surgeries. These scans are particularly useful for root canal specialists because they show root canals that are less than a millimeter wide and even reveal accessory canals that may not be visible on conventional x-rays. In cases of sleep disorders such as sleep apnea, a CBCT during sleep can be used to view a person’s airway and how it may be blocked by the tongue and other soft tissues in a person’s throat during sleep.
Compared to background radiation, the amount of radiation delivered in dental x-rays is minimal. A CBCT delivers a dose of radiation that is less than a typical full mouth x-ray series but more than a typical two dimensional panoramic radiograph. Generally CBCT scanners deliver lower doses than medical CT scanners.
With one low-dose CBCT scan, we can get an accurate idea of the internal structure of your bones and teeth and how they are situated in relation to each other. Prior to the availability of such images, many of these relationships had to be discovered in the course of a surgery or other treatment. Thus such a scan can aid greatly in the quality of treatment you will receive.