X-rays are an ionising form of radiation (this means they interact in certain ways with the cells in your body, unlike radio-waves for example) and their use is therefore tightly controlled by the following pieces of legislation:-
(a) the Ionising Radiations Regulations 1999 (IRR99)(5) which relate principally to the protection of workers and the public, but also address the equipment aspects of patient protection;
(b) the Ionising Radiation (Medical Exposure) Regulations 2000 (IR(ME)R2000)(6) which relate to patient protection. Access to these regulations is available to all members of the public.
Early tooth decay does not tend to show many physical signs. Sometimes the tooth looks healthy, but your dentist will be able to see from an x-ray (radiograph) whether you have any decay under the enamel, any possible infections in the roots, or any bone loss around the tooth.
X-rays can help the dentist to see in between your teeth or under the edge of your fillings. Finding and treating dental problems at an early stage can prevent future pain and expense. X-rays are usually required before having teeth extracted or during procedures such as Root Canal Treatment.
X-rays are also vital in assessing broken jaws and other emergency situations.
In children, x-rays can be used to show where the second teeth are and when they will come through. This also applies to adults when the wisdom teeth start to come through.
If you are a new patient, unless you have had dental x-rays very recently, the dentist will probably suggest having x-rays. This helps them assess the condition of your mouth and to check for any hidden problems. After that, x-rays are usually recommended every 6 to 36 months depending on the person, their history of decay, age and the condition of their mouth.
X-rays can show decay that may not normally be seen directly in the mouth, for example: under a filling, or between teeth. They can show whether you have an infection in the root of your tooth and how severe the infection is.
In children an x-ray can show any teeth that haven't come through yet, and let the dentist see whether there is enough space for the teeth to come through. In adults, it can show any impacted wisdom teeth that may need to be removed, before they cause any problems.
The amount of radiation received from a dental x-ray is extremely small. We get more radiation from natural sources, including minerals in the soil, and from our general environment.
With modern techniques and equipment such as digitisation of x-rays, risks are kept to a minimum. However, your dentist will always take care to use x-rays only when they need to.
There is a very common misconception that dental x-rays are dangerous to the unborn child and should not be taken during pregnancy. This is not true!
Dental x-rays can be taken during pregnancy, for two main reasons :-
However, you should still advise your dentist if you are pregnant and they will most likely avoid taken non-urgent x-rays until at least after the first three months of pregnancy.
There are various types of x-ray. Some show one or two teeth and their roots while others can take pictures of several teeth at once. The most common x-rays are small ones, which are taken regularly to keep a check on the condition of the teeth and gums. These show a few teeth at a time, but include the roots and surrounding areas. There are large x-rays that show the whole mouth, including all the teeth and the bone structure that supports the teeth. These are called panoramic X-rays. There are also medium-sized X-rays, which show either one jaw at a time, or else one side of the face. There are also electronic imaging systems in use today. These use electronic probes instead of X-ray films and the picture is transmitted directly onto a screen.
You might be concerned to see the dentist and nurse leave the room whilst taking your x-rays – this is not a cause for concern but simply because they may be taking hundreds of x-rays every week.
Staff limit the amount of radiation they receive by moving away from the x-ray beam. However, the risk to patients from one or two routine x-rays is very small.