X-rays, also known as radiographs, are an essential part of any dental care treatment plan. They are diagnostic, but they can also be preventative, by helping a dentist diagnose potential oral care issues in a patient’s mouth before they become a major problem. An x-ray is a type of energy that passes through soft tissues and is absorbed by dense tissue. Teeth and bone are very dense, so they absorb X-rays, while X-rays pass more easily through gums and cheeks.
X-rays are divided into two main categories, intraoral and extraoral. Intraoral is an X-ray that is taken inside the mouth. An extraoral X-ray is taken outside of the mouth.
Intraoral X-rays are the most common type of radiograph taken in dentistry. They give a high level of detail of the tooth, bone and supporting tissues of the mouth. These X-rays allow dentists to:
- Find cavities
- Look at the tooth roots
- Check the health of the bony area around the tooth
- Determine if periodontal disease is an oral care issue
- See the status of developing teeth
- Otherwise, monitor good tooth health through prevention
Benefits of X-Rays Outweigh Risks
A recent report from the National Academy of Sciences concludes that low-doses of radiation from medical and dental X-rays, natural and other manmade sources pose some risk for cancer but that risk is small and shouldn't keep people from seeking care.
The American Dental Association recommends that dentists consider exposure risk in diagnosing oral diseases and conditions.
"The dentist must weigh the benefits of taking dental radiographs against the risk of exposing a patient to X-rays, the effects of which accumulate from multiple sources over time," says the ADA and Food and Drug Administration Guide to Patient Selection for Dental Radiographs.
"The dentist, knowing the patient's health history and vulnerability to oral disease, is in the best position to make this judgment in the interest of each patient," the guidelines say.
According to the ADA, many diseases of the teeth and surrounding tissues cannot be seen when your dentist examines your mouth without X-rays. An X-ray may reveal:
- small areas of decay between the teeth or below existing fillings;
- infections in the bone;
- periodontal disease;
- abscesses or cysts;
- developmental abnormalities;
- some types of tumors.
When dental X-rays pass through your mouth during a dental exam, more X-rays are absorbed by the denser parts (such as teeth and bone) than by soft tissues (such as cheeks and gums) before striking the film.
How often X-rays should be taken depends on the patient's individual health needs. Your dentist will review your history, examine your mouth and then decide whether you need radiographs and what type. If you are a new patient, the dentist may recommend radiographs to determine the present status of the hidden areas of your mouth and to help analyze changes that may occur later. If you have had recent radiographs at your previous dentist, your new dentist may ask you to have the radiographs forwarded.
Benefits of Digital X-rays
- The film is immediately processed and available to view, whereas film takes time to be developed.
- Less radiation needed to produce the same quality image as film (digital X-rays gives 70% less exposure to radiation than conventional X-rays).
- You can enhance the digital image (such as alter brightness and contrast) with a series of processing techniques
- Digital archiving—the ability to store images on a computer.
- Digital radiography produces larger photos to better source hard-to-see cavities
- Digital radiography, though expensive to buy initially, is cheaper and more environmentally friendly in the long run
- Grey-scale of digital X-rays offers 256 shades of grey versus 16-25 shades in conventional radiography.