The benefits of X-rays are well known: They help dentists diagnose relatively common disorders such as cavities, periodontal disease and infections. Without this ability to see inside a tooth and beneath the gums, more disease would go unchecked, patients would experience more pain and discomfort and more teeth would be lost because proper treatment couldn't be started in time.

The X-rays used in dental and medical offices emit extremely small doses of radiation. However, cells can be damaged by many small doses that add up over time. That's why experts recommend that X-rays be used with precautions and only when necessary.

Several changes made by dentists or required by regulatory agencies have reduced radiation exposure in dental X-rays through the years:

• Lower X-ray dose — The single most important way dentists keep their patients safe from radiation is by limiting the X-ray beam to a small area and by reducing the amount of radiation that strays from that path. Although an X-ray machine looks quite large, the X-rays come out of a small cone that limits them to an area less than three inches in diameter. X-ray machines are well shielded and there is very little radiation exposure beyond the diameter of the beam.
• Better film — The speed of films used for dental X-rays has been improved so less exposure is needed to get the same results.
• Digital radiography — The use of digital X-rays reduces radiation by as much as 80%.
• Film holders — Dental patients used to hold X-ray film in their mouths with their fingers. Those days are long gone. Now, holders keep the film in place.
• Regular inspections and licensing — State and Health departments periodically check X-ray machines for accuracy and safety.
• Lead shields — Before you get X-rays, you will be covered from the neck to the knees with a lead-lined full-body apron and sometimes a separate neck protector. These shields have been used for decades, and many states require them. Today, however, they offer more peace of mind than actual protection because stray radiation from modern dental X-ray machines is almost nonexistent.
• Limited use of X-rays — Dentists take radiographs only when they believe they are necessary for an accurate dental assessment or diagnosis.

Current guidelines recommend that X-rays be given only when needed to diagnose a suspected problem. As a patient, you can help increase X-ray safety by talking to your dentist about how often you or your children need X-rays and why.