Whether you are a child or adult you can have dental x-rays taken of the inside or outside
of your mouth. The amount of radiation is extremely low, and is equivalent to the amount of 
exposure received on a 1-2 hour airplane flight.
Even if you are pregnant x-rays can still be taken, although they are generally kept to a minimum during this period.
Why do dentists leave the room?
Due to taking many x-rays all day long, stepping out of the room limits their ongoing exposure to radiation.
How often are dental x-rays needed?
Dental x-rays are generally taken approximately every 2 years to detect decay between teeth and check for infections.
They may need to be taken more frequently than that depending on your previous dental history.
Dental X-rays
Dental x-rays allow a dentist to see what is happening beneath the surface. Not everything that is going on in your mouth is visible to the naked eye.
What can be seen on dental x-rays? 
- Early tooth decay between teeth, under fillings and crowns.
- Abscesses, cysts and tumors between teeth.
- The presence and severity of gum disease (bone loss).
- Traumatic injuries, such as tooth and bone fractures.
- Presence and position of developing teeth.
- Presence and position of wisdom teeth.
- The position of nerves and sinuses in relation to the roots of teeth.