Why are digital x-rays needed?

Computers are a fixture in every day life. They also play an important role in our dental office. Besides using computers to track your appointments, treatment details and insurance records, we use them to help capture, store and transmit your dental x-rays.

The dental x-rays produced using the computer are called digital x-rays (also called digital images or computerized dental radiographs) and can be displayed and enhanced on the computer monitor.

Many Diseases of the oral cavity (including the teeth, surrounding tissues and bone) cannot be seen when the dentist examines your mouth. An x-ray examination may help the dentist see:

• small areas of decay between the teeth or below existing restorations (fillings)
• bone destruction from a tooth infection (e.g., an abscess) or from a cyst
• bone loss due to periodontal (gum) disease
• developmental abnormalities
• some types of tumors
• the effects of trauma
• the position of unerupted teeth in children and adults

Finding and treating dental problems at an early age can save time, money and unnecessary discomfort and help prevent serious health problems. X-rays may be able to help the dentist detect damage and disease not visible during a regular dental exam.

How are digital x-ray images made?

Digital imaging uses an X-ray machine like that used for dental radiographs made with film. But instead of film in a plastic holder, digital images are made using a small electronic sensor or image receptor that is placed in your mouth to capture the x-ray image.

When the digital radiograph is exposed, the image is either transported to a computer processor (with or without a cable), or in the case of an imaging plate, is removed and scanned by a special reader, similar to a cd player. Unlike any conventional x-ray film that may between three to five minutes to process, a digital x-ray image can be viewed quickly on the computer screen. The image is displayed in a large format on the computer screen rather than the small x-ray film that is viewed on a light box.

With digital x-ray images, technical errors can often be corrected to provide an optimal radiograph without having to make another x-ray exposure. Specific problem areas of a tooth can be enhanced with magnification as well as the brightness and contrast alterations. Viewing an enhanced x-ray image on a computer screen can help a dentist to better see a problem. Patients can more easily understand a dental problem or condition and discuss options for treatment.

The dental office can print or copy your x-rays, too. And, because the images are stored on the computer, they can easily be compared to a future x-ray image to see if and how conditions have changed.

Digital x-rays are environmentally friendly. They eliminate the need for film and film processing chemicals that generate bio hazardous waste. Special light boxes to view the traditional x-ray films are no longer needed.

Are dental x-rays safe?

Dental x-ray examinations require very low levels of radiation exposure, which makes the risk of potentially harmful effects very small.

Dental x-ray equipment and techniques are designed to limit the body's exposure to radiation. Some steps that can limit the area exposed during any dental x-ray examination include:

• limiting the size of the x-ray beam to approximately the size of the film or sensor being used, and
• using a leaded apron and thyroid shield (most x-rays are stopped by lead)   
  

The whole body radiation exposure associated with four bitewing radiographs is approximately 38 microsieverts, for example. By comparison, an airplane flight at 39,000 feet is associated with an exposure of about 5 microsieverts per hour. This means the exposure during a set of four bitewing radiographs is roughly equivalent to a seven-hour flight. These estimates are based on traditional film based x-rays; many digital x-ray systems may require even less radiation.