Hygiene Atlas

Atlas · Plate IX · Dental Radiography · 03

Radiation protection

Dose is kept as low as diagnostically acceptable through selection criteria, the fastest receptor, rectangular collimation and careful technique that avoids retakes. Since 2024 the ADA no longer recommends routine thyroid collars or lead aprons, though some states still require them. Operators stand at least 6 feet away at 90-135 degrees or behind a barrier, and never hold the receptor.

High-yield facts · 10

  1. ALARA = as low as reasonably achievable; ALADA = as low as diagnostically acceptable.S20
  2. ADA 2024: thyroid collars and lead aprons are no longer recommended for routine intraoral, panoramic, cephalometric or CBCT imaging, including pregnant patients and children.S21S20
  3. The ADA's reasons: modern equipment and rectangular collimation deliver tiny doses, and shields can block the beam and cause retakes. Some states still require shields.S21
  4. Patient protection comes from selection criteria, fastest receptor (digital or F-speed film), rectangular collimation, good technique and avoiding retakes.S20S19
  5. F-speed film needs about 60% less exposure than D-speed; digital sensors need less still.T7
  6. Operator stands at least 6 feet from the tube head and at an angle of 90-135 degrees to the central ray, or behind a protective barrier.T7
  7. Operators never hold the receptor or tube head; a parent (with protection) holds a child's receptor if needed.T7
  8. Occupational dose limit: 50 mSv (5 rem) per year whole body; declared pregnant worker: 5 mSv (0.5 rem) for the whole pregnancy; general public: 1 mSv (0.1 rem) per year.S23
  9. Personnel monitoring uses a dosimeter badge worn at waist level.T7
  10. Radiographs during pregnancy are acceptable when needed for diagnosis.S20

Facts are written in our own words; each tag links to its source. Values marked "sources vary" differ between references, so check the one your program uses.