Dental X-rays

How are Dental  X-rays used in treatment.
X-ray images, also called dental radiographs, are among the most valuable tools a dentist has for keeping your mouth and teeth healthy. By understanding what the structures of the mouth look like normally on an X-ray film, dentists can diagnose problems in the teeth and jaws. For adults, radiographs can:

Show areas of decay that your dentist may not be able to see with just a visual examination, such as tiny pits of decay that might occur between teeth

Find decay that is developing underneath an existing filling

Find cracks or other damage in an existing filling

Alert the dentist to possible bone loss associated with periodontal (gum) disease

Reveal problems in the root canal, such as infection or death of the nerve

Help your dentist plan, prepare and place tooth implants, orthodontic treatments, dentures or other dental work

Reveal other abnormalities such as cysts, cancer and changes associated with metabolic and systemic diseases (such as Paget's disease and lymphoma)

For children, radiographs are used to watch for decay and to monitor tooth growth and development. Dentists will use periodic X-rays to see whether a space in the mouth to fit all the new teeth, whether primary teeth are being lost quickly enough to allow permanent teeth to erupt properly, whether extra (supernumerary) teeth are developing or whether any teeth are impacted (unable to emerge through the gums). Often, major problems can be prevented by catching small developmental problems early and then making accommodations.

How Often Should Your Teeth Be X-rayed?
Even though no X-ray can be considered routine, many people require X-rays on a regular basis so that their dental condition can be monitored. Exactly how often this happens will depend on your medical and dental history and current condition. Some people may need X-rays as often as every six months. For others, X-rays may not be needed for as long as two years. In patients with no recent dental or gum disease and who visit the dentist regularly for check-ups, X-rays may be taken only every five years or so.

Who needs more frequent or regular radiographs? They include:

Children - Many children need X-rays every six months to one year, depending on age, because they are highly likely to develop caries. X-rays also help monitor tooth development.

Adults with extensive restoration work, including fillings - All the conditions that helped create the caries to begin with continue, making it necessary to check for decay beneath existing fillings or in new locations.

Anyone who drinks sugary sodas, chocolate milk or coffee or tea with sugar - Even mildly sugary beverages create an environment in the mouth that's perfect for decay, so anyone who drinks these beverages regularly will need to have more regular X-rays.

People with periodontal (gum) disease - Periodontal treatments may need to be stepped up if there are significant or continuing signs of bone loss.

People who are taking medications that lead to dry mouth, also called xerostomia - Saliva helps keep the acid levels (pH) in the mouth stable. In a dry mouth, the pH decreases, causing the minerals in the teeth to break down, leaving them prone to caries. Medications that can decrease saliva are those prescribed for hypertension, antidepressants, antianxiety drugs, antihistamines, diuretics, narcotics, anticonvulsants and anticholinergics.

People who have dry mouth because of disease, such as Sjögren's syndrome, or because of medical treatments that damaged the salivary glands, such as radiation to the head and neck for cancer treatment.

Smokers, because smoking increases the risk of periodontal disease.

Types of X-rays
X-rays are divided into two main categories: intraoral, which means that the X-ray film is inside the mouth; and extraoral, which means that the film is outside the mouth.

Intraoral radiographs
Intraoral X-rays are the most common radiographs made. If you're like most people who visit the dentist, you've had many sets of intraoral radiographs in your life and you'll likely have many more. Because they give a high level of detail, these are the X-rays that allow dentists to find caries, look at the tooth roots, check the health of the bony area surrounding the tooth, see the status of developing teeth, and otherwise monitor good tooth health. The various types of intraoral X-rays show different aspects of the teeth:

Bite-wing X-rays highlight the crowns of the teeth. On each radiograph, the upper and lower teeth in one portion of the mouth are shown, from the crown to about the level of the jaw.

Periapical X-rays highlight the entire tooth. On each radiograph, the teeth from either the upper or lower jaw in one portion of the mouth are shown. The difference from bitewings is that in a periapical X-ray, the whole tooth is shown, from the crown down past the end of the root to the part of the jaw where the tooth is anchored.

Periodically, a dentist may recommend a "full-mouth radiographic survey," or FMX. This means that every tooth, from crown to root to supporting structures, will be X-rayed using both bitewing and periapical radiographs.

Occlusal X-rays are larger and highlight tooth development and placement. On each radiograph, nearly the full arch of teeth in either the upper or lower jaw is shown. These X-rays are taken with the X-ray machine either pointing straight down from near the nose (to take pictures of the upper jaw and teeth), or straight up from under the chin (to take pictures of the lower jaw and teeth).

Digital radiographs are one of the newest X-ray techniques around. Because it is so new and because the machines can be so expensive, your dentist may not have it yet; but watch for this process to become standard in the future. With digital radiographs, film is replaced with a flat electronic pad or sensor. The X-rays hit the pad the same way they hit the film. But instead of developing the film in a dark room, the image is electronically sent directly to a computer where the image appears on the screen. The image can then be stored on the computer or printed out. One of the great advantages of this process is that radiographs can be digitally compared to previous radiographs in a process called subtraction radiography. The computer can digitally compare the two images, subtract out everything that is the same and give a clear image of anything that is different. This means that tiny changes that may not be noticeable with the naked eye can be caught earlier and more clearly with digital-subtraction radiography. Subtraction radiography requires a specialized projection technique and additional software.

 Article source: Colgate