Dental radiographs use very low doses, reduced further by digital sensors. Safety rests on taking only necessary images and using proper protection.
Dental radiographs deliver one of the lowest doses in medical imaging, and digital sensors have reduced it further. Declining a radiograph your dentist considers necessary usually carries more risk than taking it, because hidden decay and root-tip infection progress silently.
Why images are needed
A clinical examination only shows the surfaces you can see. Many cavities begin where two teeth touch. Infection at a root tip, the position of an impacted tooth, cyst-like lesions in the jaw and bone loss in gum disease can only be assessed with imaging. Radiographs let the dentist measure rather than guess.
Types of dental radiograph
- Periapical: one tooth including the root tip, used for pain assessment and root canal work.
- Bitewing: shows decay between back teeth and bone levels.
- Panoramic: the whole jaw in one image, for impacted teeth and surgical planning.
- Cone beam CT: three-dimensional planning for implants and surgery, at a higher dose, requested only when needed.
The principles behind safety
The guiding rule is to keep dose as low as reasonably achievable. In practice: images are taken when there is an indication, not routinely; the beam is collimated to the area of interest; exposure times are short; and digital sensors need noticeably less dose than film. Existing recent images are reused instead of repeated.
Practice on lead aprons varies with equipment, since scatter from modern collimated units is small, but thyroid collars remain widely used for children and during pregnancy. Always mention if you are, or may be, pregnant.
Children and pregnancy
Growing tissues are considered more sensitive, so imaging intervals for children are set individually according to caries risk rather than by a fixed schedule. In pregnancy, non-urgent imaging can wait, but necessary images for pain, abscess or trauma may be taken with appropriate protection. An untreated infection is the greater risk.
How often?
There is no universal interval. A low-risk adult with good hygiene needs images rarely; someone with recurrent decay, periodontal follow-up or many restorations needs them more often.
Ask your dentist which image is being taken and why. See our pages on root canal treatment, oral surgery and paediatric dentistry.
