Every time the dental assistant leaves the room before an X-ray, patients think the same thing: «If they leave, it must be dangerous». This is an understandable reaction. But behind it lies a fundamental misunderstanding of how radiation protection actually works.

The assistant takes dozens of X-rays every day and leaves to protect themselves from cumulative occupational exposure. For you, one X-ray every few months delivers a dose your body receives in just a few hours of normal daily life. A single periapical X-ray equals a 4-hour flight. You don't fear flying.

I often tell patients this analogy: a flight from Hamburg to Barcelona gives you more cosmic radiation than all dental X-rays for a year combined. Let's look at the actual numbers.

Natural background radiation in Germany

Radiation doses are measured in millisieverts (mSv) or microsieverts (µSv). 1 mSv = 1,000 µSv.

Every resident of Germany receives an average of 2.1 mSv of natural background radiation per year, according to the Federal Office for Radiation Protection (BfS). Sources: radon in soil and buildings, cosmic radiation, natural radionuclides in food and water.

A flight from Hamburg to New York delivers about 0.1 mSv.

Actual dental X-ray doses

🔬 Bitewing/single tooth film: 0.001–0.005 mSv (1–5 µSv)

🔬 OPG (panoramic X-ray): 0.01–0.015 mSv (10–15 µSv)

🔬 CBCT (3D X-ray): 0.05–0.25 mSv (50–250 µSv)

🔬 Natural background: 2.1 mSv/year ≈ 140–200 panoramic X-rays

Legal framework: Radiation Protection Act 2018

In Germany, dental X-ray use is governed by the Strahlenschutzgesetz (StrlSchG) and Strahlenschutzverordnung (StrlSchV), updated in 2018 in line with EU directives.

Core principle: ALARA (As Low As Reasonably Achievable). The dentist must justify each X-ray with a clinical indication. Taking an X-ray "just in case" without clinical grounds is illegal in Germany.

Pregnancy and children

Pregnancy is not an absolute contraindication. For acute tooth pain or infection, a single bitewing X-ray with abdominal and thyroid shielding is safe. the fetal dose of 0.002 mSv is negligible. Routine X-rays are postponed to after delivery. not because of medical necessity, but as a principle of reasonable caution.

How often should X-rays be taken?

There is no universal answer, it all depends on the clinical situation. For a healthy adult with no complaints, an OPG is taken roughly every 2-3 years, bitewings (for caries between teeth) every 12-24 months. Periapicals are taken as indicated. If your dentist proposes a full set of X-rays at every visit, that's a good reason to ask about the clinical justification.

For children with active caries or orthodontic treatment, more often: bitewings every 6-12 months. The first OPG is usually at 8-9 years for orthodontic planning.

Types of dental X-rays

In my practice I use 4 types of X-rays. Each has specific indications:

  • Periapical (Einzelzahnfilm). Small 3x4 cm image of 1-2 teeth. Dose 1-5 µSv. Indications: pain in a specific tooth, root assessment, endo control. The most detailed image.
  • Bitewing. Image of upper and lower tooth crowns simultaneously. Dose 2-5 µSv. Indications: detecting caries between teeth (proximal), assessing contact points. Standard every 1-2 years in prevention.
  • OPG (Orthopantomogram, panoramic). One image of the entire jaw. Dose 10-25 µSv. Indications: first visit, orthodontics, prosthetic planning, wisdom tooth assessment.
  • CBCT / DVT (Cone Beam CT, 3D). Three-dimensional image. Dose 50-150 µSv. Indications: complex implantation, endo with canal anomaly, impacted wisdom teeth, TMJ pathology, jaw fractures.

Modern digital equipment has reduced doses by 5-10x compared to 1990s film units. I use a Sirona digital system, dose below 90 percent of StrlSchV limits.

Safety principles: ALARA

Global radiation protection standard, ALARA (As Low As Reasonably Achievable):

  • Justification. Each X-ray must have a specific clinical indication. No «check» without reason.
  • Optimisation. The dose must be as low as possible while providing diagnostic information. Modern digital equipment plus precise collimation.
  • Dose limits. Regular equipment checks (every 3 years in Germany). The dentist holds Fachkunde Strahlenschutz certification.
  • Documentation. Each X-ray is recorded in the patient's Röntgenpass. Mandatory under StrlSchG.
  • Protection. Lead apron on request, especially for children and pregnant women.

If a doctor takes an X-ray without justification, it's not just a legal violation but also unethical. You have the right to ask: «Why exactly this X-ray now?» A good dentist is always ready to explain.