Dental X-rays
Regarding dental x-rays it is always best to keep our body radiation exposure to a minimum.
We should allow necessary x-rays to be taken. To provide safety to our patients, certain procedures and precautions are followed.
X-rays should be strong enough to penetrate the tissues and weak radiation that is more prone to bounce (scatter) off the skin and teeth should be limited. X-rays should be shielded (blocked) to prevent radiation from reaching areas that are not to be exposed. Dental x-ray film has a lead backing on it so x-rays won't penetrate past the film to the opposite side of the mouth. The cone on the x-ray machine is lined with lead to prevent scatter radiation and help focus the x-ray beam onto the film. There is aluminum filtration that the beam must pass though before it touches the patient to further reduce the number weak rays that can scatter. We use lead aprons to cover and protect the body and reproductive organs and thyroid gland that is more easily affected by radiation.
We only take x-rays when we feel they are needed for diagnostic reasons and don't adhere to a set time interval to retake them. When I went to dental school the school required a complete set of films every two years and bitewings (cavity detecting x-rays) every six months. We don't follow this guide line anymore and haven't for over 30 years. In addition, we use the ultra high speed film which allows us to make shorter exposures thereby reducing the amount of radiation needed for a good image. It's also important to know that our complete set of x-rays uses much less radiation than a single chest x-ray and it equals the amount of radiation one would be exposed to if they spent the day outdoors.