More About Dental X-rays

X-rays show dentists the things they can’t otherwise see, like cavities between teeth, infection around a root surface, how close a cavity may be to the living pulp tissue in the middle of the tooth, and many other valuable pieces of information involved in making a proper diagnosis.

Dental X-ray Types

For adults, a full-mouth series of dental x-rays includes 18 different views. These are the standard x-rays in a dental office used to diagnose cavities in between teeth. They can also help diagnose cavities beneath other fillings, severity of cavities, bone level around your teeth, infection, gum disease, root canal treatments, and other important everyday oral health problems. A full series is usually taken at least every three years with supplemental films taken as needed. A patient with high risk for oral health problems or a younger patient may need x-rays more often.

A panoramic x-ray is one large x-ray that gives a full view of a patient’s mouth. These x-rays are useful for looking at development of teeth and impacted wisdom teeth, as well as infections. However, these are less diagnostic for problems such as cavities.

An occlusal view x-ray is used least frequently; this type of x-ray is taken to analyze skeletal and/or pathologic conditions of the floor of the mouth of the palate.

Dental X-ray Safety

Dental x-rays are safe. The amount of radiation you’re exposed to is negligible. It is equivalent to a few days of background radiation you encounter on a regular basis or an airplane flight. In fact, a full set of dental x-rays taken weekly would not equal the exposure to natural radiation at high altitudes.

The apron your dentist covers you with protects you from this radiation, but it’s more for peace of mind than anything else. While it does help shield some radiation from the abdomen and thyroid, the amount of radiation you’re getting is consistent with many other activities in life.

The ALARA principle is used in dental x-rays. ALARA is an acronym for "as low as reasonably achievable." This means that it is a dentist’s responsibility to make every reasonable effort to keep exposures to radiation as far below the dose limits as possible. To give you an idea of how dental x-rays compare to other x-rays: dental x-rays usually give off 0.7-1 milli roentgen per exposure.  For a set of 18 that is taken once every three years, it will total around 18 milli roentgens. In comparison, a typical medical x-ray will be about 20 milli roentgens. In a year, it has been estimated that you’ll be exposed to 100 milli roentgens of radiation from the sun alone.

If you’re pregnant, and the problem is minor in nature, your dentist may avoid all x-rays until after the baby has been delivered. But, if there is an untreated problem, it could cause a health risk to the mother and the unborn child. The radiation from dental x-rays is low, and every precaution is taken to make sure that ALARA is achieved. If it is feasible, your dentist will most likely wait until the third trimester to take any x-rays.

Traditional X-rays vs. Digital X-rays

The most significant difference between traditional and digital is that the digital x-rays are much quicker, and there’s no time spent waiting on the x-rays to develop.  Digital x-rays also make it easier to have a patient’s chart available on computers. In the case of digital dental x-rays, the picture can be enlarged to get a better view, color can be contrasted, and the image can be zoomed or manipulated to a targeted area.

However, the sensors for digital x-rays are often larger and thicker than traditional x-ray sensor plates. This can cause discomfort in a patient’s mouth or inability for a patient to close properly. Also, it has been argued that the digital x-rays are not quite as diagnostic yet as the traditional method.

CAT Scans

CAT or CT (computerized axial tomography) scans can give a doctor a three-dimensional image of the inside of an object. CT scans are very useful in placing dental implants, because they provide a full picture of a patient’s underlying bone, tissue and nerves. Because implants are very technique sensitive, your dentist needs more specifics than your average two-dimensional dental x-ray provides. CT scans can also be used for accurately diagnosing endodontics, orthodontics and TMJ analysis. They can help assess tumors, growths and fractures that may not be visible in any other fashion.