In dentistry, x-rays are one of the most popular types of diagnostics. An image of the teeth allows you to clarify the diagnosis, assess the general condition and internal structure of the tooth, the condition of the bone tissue and gums, and choose the right treatment tactics. To monitor treatment, it is also necessary to take dental x-rays. And prosthetics, implantation, root canal treatment and other operations are generally impossible without this examination.
Let's find out more about this indispensable diagnostic method.
When X-rays, OPTG and CT may be required
An x-ray is a targeted photograph of one or more teeth. OPTG or orthopantomogram is a panoramic image that captures both jaws. CT is a computer tomogram. It allows you to obtain three-dimensional or volumetric images of the entire human jaw system. Each of these types of diagnostics is used for certain indications:
- X-rays are performed when treating a specific tooth: in the presence of caries, pulpitis, periodontitis, suspected cyst or granuloma. Allows you to determine the extent of tooth damage, as well as the condition of the tissues around the root,
- An orthopantomogram is indispensable in the presence of inflammatory processes in periodontal tissues and jaw bone. It is carried out both during multiple dental treatment and in preparation for orthopedic, orthodontic treatment or dental implantation. Allows you to assess the condition and volume of bone tissue, clarify the position of the maxillary (nasal) sinuses of the upper jaw, nerves and other anatomically important elements,
- CT scan is performed for certain indications. Most often in the presence of tumors of the jaw system (to determine their volume in all dimensions), as well as before dental implantation, especially in complex cases.
Today in dentistry (and in medicine in general) digital devices are used instead of film ones. They have a much lighter load, and they also use shorter shutter speeds to create a photo. For comparison: a modern digital visiograph takes up to 0.3 seconds to take an image, a film X-ray machine requires up to 1.5 seconds.
The Smile-at-Once clinic uses the latest generation CT-Scan tomograph. It allows you to get both a targeted or panoramic, and a three-dimensional digital image. Thanks to minimal radiation exposure, the equipment is completely safe and allows repeated diagnostics without harm to the human body.
How is dental x-ray examination performed?
The photo is taken in a special room with lead-protected walls and floors. The doctor asks the patient to remove metal jewelry and accessories, as they may distort the results of the study. The vital organs of the body are protected by an apron with lead inserts. Features of the study depend on the method used.
When receiving a targeted image, the doctor directs an x-ray beam to the area of the jaw being examined from the side of the face or to an area of the oral cavity. An orthopantomogram is obtained in a different way. The patient fixes his head in a special device, grabs the plate in a disposable cover with his teeth and remains motionless while the mobile part of the device makes a full revolution around the head.
Is it dangerous to take pictures?
According to SanPiN1, when performing X-ray procedures for preventive purposes, radiation exposure should not exceed 1000 microsieverts (µSv) per year. We are talking specifically about prevention, since for medicinal purposes the indicator can be much higher.
In terms of the number of shots it looks like this:
- 500 targeted shots (1-3 µSv),
- 80 OPTG (13-17 µSv),
- 20 digital CT scans (50-60 µSv).
For comparison, here is a table that shows the radiation doses that a person receives during diagnostic procedures in dentistry, in other areas of medicine and in life in general. The last table shows parameters that are truly dangerous to the body and can be fatal.
| In dentistry | In other areas of medicine | In life | Dangerous indicators |
| 1-3 μSv – one targeted shot | 30-60 µSv – one digital fluorography, 150-250 µSv – old type film FOG | 5 µSv – 3 hours in front of a computer or TV | 750 thousand µSv – minor changes in blood composition |
| 13-17 μSv – one panoramic image (OPTG) | 500-700 µSv – one mammography procedure | 20-30 µSv – one 2-3 hour flight | 1 million µSv – mild radiation sickness |
| 50-60 μSv – one CT procedure in dentistry | 2000 μSv – one head CT procedure | 2000-3000 μSv – natural dose of radiation per person per year (food, solar radiation, air) | 7 million µSv – lethal dose of radiation |
As can be seen from the table, irradiation can cause harm (minor and short-lived) only when a dosage of 750 thousand µ3V is reached, while only one thousand µ3V is allowed for diagnosis. Therefore, 20 CT images or 80 panoramic images will not cause any harm to the body.
Are there any contraindications to X-ray examination?
Dental X-rays are not performed on patients with severe bleeding in the mouth, or those who are unconscious or in critical condition.
Pregnancy is considered a relative contraindication. In this condition, women should not undergo dental procedures involving radiation until 4-5 months. But in each individual case, the expectant mother needs to personally consult a doctor, since situations are different.
A breastfeeding woman can undergo an X-ray examination. But it is advisable to resort to digital methods and skip one or two feedings after the session.
Is it possible to carry out diagnostics during pregnancy?
According to SanPiN, X-ray examinations are allowed in the second half of pregnancy using protective equipment, provided that the radiation dose does not exceed the same 1000 μSv. However, it is recommended to refrain from taking x-rays in the first and last 12 weeks, i.e. in the first and last trimesters.
Do not be afraid of undergoing diagnostic procedures during pregnancy. Even ordinary caries is an infection that, if not properly treated, can spread throughout the body and lead to infection of the fetus. Therefore, it is better to receive a small and completely safe dose of radiation than to carry out complex dental treatment blindly, not knowing how deep the inflammatory process is.
After the baby is born, i.e. During breastfeeding, dental x-rays can be taken, even more than once (within reasonable limits). Radiation doses are minimal, so radiation does not accumulate in breast milk, and there will be absolutely no harm to the baby. There is also no need to pump or skip feedings.
Advantages of X-rays in dentistry
One of the most common diseases that occurs in almost every patient is caries. If the disease is detected at an early stage and treated, it is not dangerous. But in the absence of timely intervention, caries causes serious complications (pulpitis, periodontitis and others), which are accompanied by severe toothache and the treatment process in such cases takes a lot of time and effort. This is why it is so important to visit the dentist regularly for preventive examinations. It is recommended to undergo an examination every six months, which may include x-rays.
If a root canal filling is planned, the dentist needs to see its structure and possible individual characteristics. After filling, the specialist prescribes an x-ray for control. This is very important, because if a filling defect is not detected in time, inflammation will develop after some time, which can lead to tooth loss.
More information about caries treatment can be found here
Situations when taking photographs is strictly prohibited
Such situations practically never occur. On an individual basis, X-rays are considered in cases where the patient receives radiation in other areas of life: for example, in hazardous work, while undergoing chemotherapy or radiation therapy. But again, when X-raying the state of the jaw system, the radiation is so small that it will not affect the overall picture.
Thus, you should not be afraid to take photographs - in single quantities they are quite acceptable and will not affect your health at all.
It is important to understand that such diagnostic procedures allow for better treatment, especially with dental implantation, the results of which will last not a couple of years, but for many years of life. 1 Sanitary rules and regulations (SanPiN) 2.6. 2.6.1.1192-03 for the design and operation of X-ray rooms, devices and the conduct of X-ray examinations.
What can a doctor see on an x-ray?
He can see:
- total number of teeth;
- anatomical features of the structure of the maxillofacial region;
- level, bone height;
- possibility of installing implants.
X-rays are also done for the purpose of establishing a diagnosis, when the doctor cannot make one based solely on the patient’s complaints.
X-rays are also done to monitor the doctor’s work. It shows how:
- canals are sealed;
- tooth removed;
- an implant was installed.
Radiation exposure during CT scan of the jaw
Clinics of the Smile Factor network use new generation tomographs, the radiation from which during scanning is reduced to a minimum.
While the exposure time of standard (outdated) X-ray machines is about 2-3 seconds, the equipment we use operates with a exposure time of 0.05 seconds (this is the time of direct exposure to radiation). To understand the size of the radiation exposure and find out for yourself how often you can do a CT scan of your teeth so that it is not harmful to your health, you need to do more than just familiarize yourself with dry data figures. It would be more clear to consider a comparison of radiation from a tomograph with radiation in everyday life:
- Watching any TV at a distance of less than 2.5 meters from the screen for 3 hours gives 0.5 millisievert (mSv). Accordingly, five days of watching TV for 3 hours is equal to the same radiation exposure that can be obtained with 1 x-ray of the jaw.
- Working on a computer/laptop for more than 3 hours is 1 µSv, which is equal to 1 targeted photograph of a tooth.
- A plane flight from St. Petersburg to Omsk, Surgut or Turkey takes 3.5 hours. During this time, a radiation dose of 10 mSv will be received, which is equivalent to 5 CT images.
And this is without taking into account the daily exposure of your body to radiation from the refrigerator, microwave oven and other regularly used appliances. The examples given are enough for you to understand that the radiation exposure from a CT scan of the jaw is small and its effect is not as harmful to health as it might seem. But the results of the study will help not only to correctly diagnose diseases, but also to correctly carry out some dental operations, for example, implantation.
How is the load reduced during x-rays?
All information about the radiation examinations performed, their number and radiation dose is entered into the medical record. If a critical dose accumulates over the course of a year, then prescribing another x-ray is highly undesirable.
To control the workload, the radiographer must have maximum information, so it is important to report all previous examinations and possible contraindications.
To protect the body, three main methods of protection are used:
- Protection by distance. The X-ray tube is placed in a special protective casing. It does not allow X-rays to pass through, which are directed at the patient through a special “window”. In addition, at the exit of the rays from the tube, an X-ray machine diaphragm is installed, with the help of which the irradiation field is increased or decreased.
- Time protection. The patient should be irradiated for as little time as possible (short shutter speeds when taking pictures), but not to the detriment of diagnostics. In this sense, images provide less radiation exposure than transillumination.
- Shielding protection. Parts of the body that are not to be photographed are covered with sheets and aprons-skirts made of leaded rubber. Particular attention is paid to the protection of the genital organs and thyroid gland, as they are the most sensitive to x-ray radiation.
Where can I do it?
Most dental clinics have an X-ray room where the patient can undergo this procedure without leaving the building and return to his dentist with the images. State clinics also have such installations, but they are exclusively of the old type. This means that you will have to go through the procedure several times and pay less. Old equipment also has high radiation doses. Unfortunately, many private dentistry are also equipped with such equipment. Sometimes a private doctor may refer you to another diagnostic center to obtain data. Cone beam computed tomography is only available in progressive private clinics, but the accuracy of the results fully pays for itself.
The price of the service will depend on the type of examination. Thus, bitewing radiography costs from 3 to 10 dollars, depending on the number of images. At the same time, prices are almost the same in both public and private institutions. A panoramic image will cost approximately $20-25. It can only be done in private institutions, but some clinics can provide this service for free if the patient is being treated by them. The most expensive diagnostic is CBCT, which is done in single diagnostic and dental centers. Its cost will be 50-60 dollars.
Is dental CT harmful to the health of pregnant women?
Often women are interested not only in how often dental CT can be done, but also whether this diagnostic procedure is available for pregnant women. Experts give the following answers to this question:
- First half of the term . Computed tomography is indicated only if absolutely necessary. For example, if there is an urgent need to identify tumors.
- Second half of the term . During this period, there are no restrictions or prohibitions on computed tomography and the resulting radiation exposure for expectant mothers.
It is worth understanding that an experienced doctor will never send a patient for a tomography unless necessary. But, if when collecting a clinical picture or during treatment it is necessary to see what a CT scan of the teeth and jaws shows, you cannot do without an X-ray scan. Be sure to tell your doctor that you are pregnant (if this is not obviously noticeable) so that he can reschedule a CT scan or prescribe a suitable alternative diagnostic test that will not be harmful to the health of the expectant mother and fetus.
Frequently asked questions from patients
Are x-rays harmful?
Radiography is based on radiation exposure. This sounds quite threatening to the average person. Meanwhile, every person receives a dose of radiation every day, even our bodies are radioactive. The background radiation level per day is 10 μSv (microsieverts). To obtain 4 photos with a bitewing X-ray, the patient receives 20-51 μSv. A panoramic image gives 5-25 μSv. CBCT is accompanied by a higher radiation dose; in one session a person receives from 20 μSv to 700 μSv. The level of radiation will depend on the settings and type of device, and the width of the area being studied.
Thus, there is no direct threat in the procedure. However, radionuclides can accumulate, so diagnostics are prescribed if necessary. After the session, the radiologist must write down how many sieverts the patient received, this will make it possible to calculate the next dosage with minimal harm to the person. After the examination, it is advisable to eat more carrots, apples, radishes, beans and citrus fruits. These products will help remove radionuclides from the body.
How often can it be done
Best materials of the month
- Coronaviruses: SARS-CoV-2 (COVID-19)
- Antibiotics for the prevention and treatment of COVID-19: how effective are they?
- The most common "office" diseases
- Does vodka kill coronavirus?
- How to stay alive on our roads?
The type of x-ray and its frequency depends on the condition of the oral cavity and the complexity of the treatment. It is better to do CBCT no more than 3 times a year. Bitewing film photographs are prescribed no more than 7 times a year; the new technology uses lower radiation doses, so there may be more digital diagnostics. The acceptable norm is 7 diagnostic studies per year. When changing dentists, it is not necessary to take new photographs; it is enough to take the ones you already have with you to the appointment. If digital data has been lost, it can be requested from the clinic that conducted the examination. CBCT results are stored for up to a year in the archives of medical centers.
