The dose from modern dental X-rays is very low (a single intraoral X-ray 2–5 µSv, a panoramic X-ray 10–24 µSv, CBCT 30–1000 µSv depending on the FOV), and when they are taken for a clinical indication the cancer risk is considered statistically negligible. Digital equipment, the lead apron, the thyroid collar and the ALARA principle make dental X-rays safe in modern dentistry. There is no “annual limit” for X-rays — every exposure is justified by a clinical reason; repeat X-rays without a reason, however, are not acceptable.
The most frequently asked question about the safety of dental X-rays is this: “Isn’t this radiation harmful to me?” The answer is not a single sentence, it depends on context — the clinical indication, the type of image, the technology of the equipment and the patient’s individual circumstances (age, pregnancy) all play a role.
In this article I explain the risk–benefit balance of dental X-rays in plain language: doses in concrete figures, the question of “how many times can I have one” and the rules of protection. The dose from CBCT is a separate topic: Is CBCT radiation high?.
What is radiation, and what type of radiation does a dental X-ray emit?
Dental X-rays use ionising radiation (X-rays). This means that as the radiation passes through tissue it can ionise molecules and, in theory, damage DNA. However:
- The dose used is very low and very localised.
- The body itself is able to repair such small amounts of damage.
- The cancer risk is so small that it is statistically impossible to measure.
For this reason the equation “X-ray = cancer” is not scientifically correct — the dose–effect relationship is always context-dependent.
How much radiation is the dose?
When a dentist says “it is a low dose”, the actual figure often remains unclear to the patient. Below are the effective doses of dental X-rays in numbers.
What do µSv and mSv mean?
Effective dose is a calculated measure of the risk that radiation creates for the whole body; it allows different examinations to be compared with one another. Its unit is the sievert: 1 sievert (Sv) = 1000 millisieverts (mSv) = 1,000,000 microsieverts (µSv). Because the dose from dental X-rays is very small, it is written in µSv, whereas large doses such as those from computed tomography are written in mSv. For the unit “rem” found in older literature: 1 mSv ≈ 100 mrem.
Typical doses by type of dental X-ray
The figures apply to modern digital equipment; the actual dose varies within these ranges depending on the device model, the exposure parameters, the size of the patient and the protocol. The panoramic and intraoral doses are based on publications calculated with the 2007 ICRP methodology (Ludlow et al., JADA, 2008).
| Type of X-ray | Typical effective dose |
|---|---|
| Periapical (single tooth), digital | 2–5 µSv |
| Bitewing (2 images) | 4–10 µSv |
| Full-mouth intraoral series (14–18 images) | 35–170 µSv (depending on collimation) |
| Panoramic X-ray (OPG) | 10–24 µSv |
| Lateral cephalometric X-ray | 3–6 µSv |
| Small FOV CBCT (a few teeth) | 30–100 µSv |
| Medium FOV CBCT (one jaw) | 100–200 µSv |
| Large FOV CBCT (both jaws + sinus) | 200–1000 µSv |
| Low Dose CBCT protocols | considerably lower than the standard protocol for the same FOV |
Note: with film-based analogue intraoral X-rays the dose used to rise to 20–50 µSv; an analogue panoramic image from the 2000s delivered 40–70 µSv. Now that digital detectors (CCD, CMOS, PSP) have become the standard, doses have fallen several times over.
Comparison with natural background radiation and everyday life
| Source | Effective dose |
|---|---|
| Daily natural background (world average, UNSCEAR) | 6–8 µSv |
| Annual natural background (world average) | ~2400 µSv (2.4 mSv) |
| Baku–London flight (approximately 5 hours) | 20–35 µSv |
| Long-haul flight (7–8 hours) | 30–50 µSv |
| Chest X-ray (single projection) | 20–50 µSv |
| Mammography | 300–400 µSv |
| Head computed tomography (conventional CT) | 1500–2500 µSv |
| Chest computed tomography | 5000–8000 µSv |
In other words:
- one intraoral X-ray ≈ roughly half a day to one day of natural background radiation;
- one panoramic X-ray ≈ 2–3 days of natural background radiation, or one medium-haul flight;
- a small FOV CBCT ≈ 1–2 weeks of natural background radiation;
- a large FOV CBCT ≈ approximately 5–40% of the dose of one head CT.
What does the dose depend on?
- The technology of the equipment — digital detectors require a considerably lower dose than film.
- Exposure parameters — kVp, mA and exposure time; these are set lower in the paediatric protocol.
- FOV (field of view) — in CBCT, the larger the field, the higher the dose.
- Collimation — directing the beam only at the area required (in an intraoral series, rectangular collimation reduces the dose several times over).
- The size of the patient — smaller heads receive a lower dose.
- Low-dose protocols — Low Dose CBCT modes.
The scientific consensus: the risk is very low, but not zero
The official position of the international radiological bodies (ICRP, UNSCEAR, ADA):
- At low doses (below 100 mSv) the cancer risk cannot be measured directly; as a precaution the risk is assessed using the linear no-threshold (LNT) model — that is, every dose is assumed to carry some risk, however small.
- In ICRP Publication 103 the nominal risk coefficient for the whole population is approximately 5.5% / Sv; this means that 1 mSv of additional dose corresponds to an increase of about 1 in 18,000 in the lifetime cancer risk. For one panoramic X-ray (10–24 µSv) this figure is approximately 1 in 1,000,000, and for one intraoral X-ray it is several times smaller still.
- The contribution of a single dental X-ray to collective statistics is negligible, yet medical radiation is managed not with a “zero risk” stance but with the principle of “the minimum necessary” (ALARA).
What does this mean in practice? — Every X-ray is taken for a clinical reason, not as a preventive “once a year” routine.
How many X-rays can be taken?
One of the questions patients ask most often is this: “They are asking for a second X-ray this year — isn’t that dangerous?” The answer: for dental X-rays there is no specific “annual limit”. The ICRP limit of 1 mSv/year applies to the dose the population receives from artificial sources; no official limit is set for patient examinations, because every exposure is justified by its clinical benefit. As a guide: even several panoramic images and one CBCT in a year add up to less than the annual natural background dose.
The ALARA principle in practice
ALARA (“As Low As Reasonably Achievable”) means that every image is taken only when it is clinically justified and with the lowest possible dose. So “a preventive panoramic X-ray every 6 months” is not the right approach; a new image is prescribed only if it will provide new clinical information and change the decision. The ADA’s 2024 recommendations also set out as a basic rule that X-rays should be prescribed on an individual clinical indication rather than to a “routine calendar”.
Who needs them, and how often?
- Healthy adult with no active problems: if a general screening image is needed, a panoramic X-ray usually every 3–5 years; a preventive panoramic image is not obligatory.
- During active treatment (implant, root canal, surgery): a panoramic X-ray and/or CBCT for planning before an implant; for follow-up after an implant at 6 months, 1 year, and then every 2–3 years; follow-up of complex root canal treatment every 6–12 months as indicated. In these scenarios 2–3 images a year can also be clinically justified.
- Orthodontic treatment: a panoramic X-ray + lateral cephalometric X-ray at the start; over 2–3 years of treatment usually 2–4 panoramic images in total.
- Children: an annual preventive panoramic X-ray is not recommended for a healthy child; where there is an orthodontic or developmental indication, every 12–24 months. More detail: Are dental X-rays safe for children?.
- Pregnant women: elective images are postponed; in urgent cases they are taken with special protection.
| Scenario | Typical number of panoramic images per year |
|---|---|
| Healthy adult, no active problems | 0–1 (rarely) |
| General examination + follow-up of root canal treatment | 1 |
| Active implant treatment | 1–2 (+ 1 CBCT) |
| Active orthodontic treatment (1st year) | 1 |
| Complex oral surgery (cyst, wisdom tooth) | 1–2 (+ CBCT) |
| Child — start of orthodontic treatment | 1 |
| Pregnant (elective) | 0 (postponed) |
The table gives average figures; the final decision is made by the dentist for each patient. On what a panoramic image shows: What is a panoramic X-ray?.
Lifetime accumulated dose
The key measure of radiation risk is not the dose of a single image but the lifetime accumulated dose — and the contribution of dental X-rays to this total is very small. An example calculation for a 30-year-old patient:
- childhood and adolescence: 2–4 panoramic images, 8–10 intraoral images, perhaps 1 CBCT ≈ 200 µSv;
- one panoramic image every 3 years in adulthood ≈ 60 µSv;
- one course of implant treatment (1 CBCT + 1 panoramic image) ≈ 100 µSv.
A total of roughly 0.35–0.4 mSv. By the age of 30 the same patient will have received about 70 mSv from natural background radiation — meaning that dental X-rays account for less than 1% of lifetime radiation. This is why the answer to “I have had two X-rays taken, is it safe now?” is usually: yes — provided that every image had a clinical reason.
How is safety ensured?
In modern dentistry the standard protective rules for dental X-rays are as follows:
1. The ALARA principle
Every image is justified by a clinical indication. If there is an alternative (a clinical test, a previous result), a new image is avoided.
2. Digital equipment
Digital detectors (CCD, CMOS, PSP) require a considerably lower X-ray dose than analogue film. The majority of modern clinics already work with digital equipment.
3. Lead apron and thyroid collar
A lead-containing apron placed over the chest, abdomen and reproductive organs protects against scattered radiation. A thyroid collar placed around the neck is useful for intraoral images, especially in children; during panoramic imaging and CBCT it is used selectively, as it can obstruct the field of view. Note: the ADA’s 2024 recommendations no longer consider the routine use of an apron and thyroid collar necessary with digital equipment that has proper collimation — but if the patient wishes to use them and they do not interfere with the image, their use is harmless.
4. Collimation and correct aiming
The X-ray beam is directed only at the area required, so the surrounding tissues are not exposed.
5. Paediatric protocols
For children, the exposure time and the mA (milliamperes) are set lower; in CBCT the smallest possible FOV is selected.
6. Reusing previous images
Results are archived in DICOM format — a previous image can be used for new treatment, and unnecessary repeats are avoided.
The most widespread myths about the “harm” of X-rays
Myth 1: “One X-ray inevitably causes cancer”
False. The dose of one dental X-ray is very small and no direct cancer risk can be demonstrated.
Myth 2: “X-ray machines emit radioactivity, so it is dangerous to be nearby”
False. X-rays are produced only at the moment the image is taken; when the machine is switched off it emits no radiation. A patient does not become “radioactive” after having an X-ray.
Myth 3: “Dentists harm themselves because they take many X-rays every day”
Dentists step out of the X-ray room or stand behind a radiation barrier — so they are, in effect, not exposed to radiation. In addition, every clinic uses dosimeter monitoring.
Myth 4: “Digital X-rays deliver as much radiation as film”
False. Digital equipment was developed precisely in order to reduce the dose.
Myth 5: “A panoramic X-ray is far more dangerous than an intraoral one”
The dose of a panoramic image (10–24 µSv) is higher than that of an intraoral image (2–5 µSv), but this difference is entirely negligible in terms of clinical risk. One panoramic image = the dose of 4–5 intraoral X-rays.
Precautions for special groups
Pregnant women
All elective X-rays are postponed. Where there is an urgent need (severe pain, infection, trauma), the risk–benefit balance is assessed and the image may be taken with special protective measures. More detail: Can you have an X-ray during pregnancy?.
Children
Children are more sensitive to radiation than adults (their cells divide rapidly), and the same exposure can translate into a higher effective dose in a small body. For this reason the clinic applies a paediatric protocol: lower kVp, shorter exposure, smaller FOV. With the correct protocol, the dose of a child’s X-ray is even lower than that of an adult protocol. More detail: Are dental X-rays safe for children?.
Chronic conditions
For patients receiving chemotherapy or with immunodeficiency, the clinical protocol is individualised in consultation with the doctor.
The clinical benefit of X-rays — why the risk–benefit balance is positive in practice
Not taking a dental X-ray is also a risk — because:
- Hidden tooth decay goes untreated and progresses.
- A cyst grows and erodes the surrounding bone.
- An implant is placed without planning — leaving it open to failure.
- It is not known that a wisdom tooth lies close to the nerve canal — and nerve damage may occur during surgery.
- Root canal treatment is left incomplete — and infection develops later.
In other words, not taking an X-ray also carries clinical risk. When the very low risk of radiation is compared with the risk of failing to detect hidden pathology, the balance of benefit usually falls in favour of the X-ray.
What happens in the body after an X-ray is taken?
In physical terms, briefly: the X-ray beam passes through the body for an instant and is partly absorbed by the tissue. Once the image is taken, the patient does not become radioactive; they do not “transmit radiation” to anyone.
The great majority of the cells ionised in the tissue are restored by the body’s own natural DNA repair mechanism. In rare cases where the repair is not complete, the body is able to eliminate that cell through programmed cell death (apoptosis).
How can patients themselves keep the dose to a minimum?
- Keep your previous X-rays (as a digital file or a printout) and give them to the dentist at a new clinic — if you had a panoramic image taken elsewhere 6 months ago, a repeat is often unnecessary.
- When you change clinic, if a new “preventive” X-ray is requested, ask why.
- Ask your dentist: “What is the approximate dose for this X-ray?”, “Is the equipment digital?”, “Is a special protocol used for my child?” — a good clinic answers these questions transparently.
- Give preference to clinics with digital equipment.
- Always tell your dentist about pregnancy.
The answer: is it dangerous?
A dental X-ray taken for a clinical indication is not considered dangerous — the doses are very low and the risk is statistically negligible. But “it is safe” does not mean the dose is zero — which is why unnecessary repeats are avoided (ALARA).
So the right question is not “is it dangerous?” or “how many times can I have one?”, but “is it necessary?” Only a dentist can answer that question.
What to look for in safe dental X-rays in Baku?
What you should pay attention to for X-ray safety in a good clinic:
- Digital equipment and the availability of low-dose protocols.
- A paediatric protocol and paediatric expertise.
- Asking about pregnancy and gathering information.
- Imaging on a clinical indication — no repeat “preventive” images without a reason.
- Archiving in DICOM format — so that older X-rays can be reused.
At our clinic, dental radiology services meet all of these standards.
Frequently asked questions (FAQ)
Can a single dental X-ray cause cancer?
The general scientific consensus: the dose of a single dental X-ray (2–24 µSv) is statistically negligible in terms of cancer risk. Multiple images over the long term are managed with the ALARA principle.
What do µSv and mSv mean?
They are the units of effective radiation dose: 1 mSv (millisievert) = 1000 µSv (microsieverts). Doses in dental radiography are given in µSv, and in computed tomography in mSv.
Is the dose of a panoramic X-ray high?
A panoramic X-ray delivers 10–24 µSv — roughly equivalent to 2–3 days of natural background radiation, or one medium-haul flight.
How many times a year can a panoramic X-ray be taken?
There is no official annual limit; in a healthy adult patient a preventive panoramic image every 3–5 years is usually sufficient. During active implant, orthodontic or surgical treatment, 2–3 images a year can also be justified on clinical indication.
Is it dangerous to have two panoramic X-rays in a year?
If there is a clinical indication, two images a year are not considered dangerous in terms of total dose — a total of 20–50 µSv, which is less than one week of natural background radiation. Repeat images without a reason, however, are not acceptable.
Is a digital dental X-ray safer than a film X-ray?
Yes. Digital equipment delivers a considerably lower dose than film radiography and shows the result immediately.
Is a lead apron necessary for dental X-rays?
It has been the standard for many years and it is harmless. According to the ADA’s 2024 recommendations, a routine apron and thyroid collar are no longer considered necessary with properly collimated digital equipment; they can be used if the patient wishes and if they do not interfere with the image.
Are dental X-rays more dangerous for children?
A child’s body is more sensitive to radiation. When taken on a clinical indication and with a paediatric protocol (low dose, small FOV), they are safe; an annual preventive panoramic image is not recommended for a healthy child.
Can dental X-rays be taken during pregnancy?
Where possible they are postponed; when there is an urgent need they are taken with special protection.
About the author
Dr. Bakhtiyar Aliyev — dentist, clinical director of the Smile by Dr. Bakhtiyar clinic. This article has been medically reviewed by Dr. Bakhtiyar.
This article is for general information only and is not a substitute for individual medical advice.
Book an appointment
For safe, modern dental X-rays in Baku, you are welcome to contact our clinic. Book an appointment online or get in touch with us.
Sources
- Patient risk related to common dental radiographic examinations: the impact of 2007 International Commission on Radiological Protection recommendations regarding dose calculation — Journal of the American Dental Association, 2008
- Optimizing radiation safety in dentistry: Clinical recommendations and regulatory considerations — Journal of the American Dental Association, 2024
- ICRP Publication 103: The 2007 Recommendations of the International Commission on Radiological Protection — International Commission on Radiological Protection, 2007
- UNSCEAR 2008 Report: Sources and effects of ionizing radiation, Volume I — United Nations Scientific Committee on the Effects of Atomic Radiation
- X-Rays/Radiographs — Oral Health Topics — American Dental Association
This article is for general information only and does not replace an individual diagnosis, examination or treatment. Consult a doctor for a decision about your case.