Why do we need x-rays in dentistry?

A dental x-ray is a detailed image of the teeth, bones and soft tissues around them, allowing us to identify various dental and oral problems. X-rays can show cavities, hidden dental structures (such as wisdom teeth), bone loss and other abnormalities that cannot be detected during a visual examination and a routine dental consultation. Dental X-rays are usually performed annually. It is also actively used for follow-up monitoring of teeth after treatment. X-rays may be prescribed more often if your doctor monitors the development of a dental problem directly during treatment.

Types of dental x-rays

Today, there are four main types of dental x-rays according to their intended purpose:

Bite X-ray – an image of the upper and lower rows of teeth in a closed state. This type of x-ray helps identify malocclusions, subsidence of bones, interdental caries, and the presence of hidden cavities. Also allows visualization of bone loss due to severe gum disease or dental infection.
A peripheral x-ray of a tooth depicts the entire tooth, its surface and internal parts, that is, it is an image from the crown of the tooth to the part of the bone that supports it. These x-rays are used to identify dental problems below the gum or jaw line, such as affected teeth, abscesses, cysts, tumors, and bone changes associated with certain diseases.
An occlusal photograph is aimed at identifying the condition of the roots of the teeth and the dental floor. It is actively used for jaw fractures, cleft palate symptoms, abscesses and suspected presence of hidden/not yet erupted teeth (including wisdom teeth). Occlusal x-rays can also be used to detect foreign objects.
Panoramic x-ray of teeth. Allows you to obtain a detailed image of the jaws, teeth, nasal cavity and jaw joints. This type of x-ray does not allow visualization of cavities. This type of x-ray is effective in diagnosing tooth fractures, various bone pathologies, cysts and neoplasms. Actively used before orthodontic treatment.

What types of X-ray diagnostics are used in dentistry?

The main types of images obtained during x-ray photography of the dental system:

Sighting. Provides information about the condition of one or more teeth and adjacent tissues. This helps the specialist assess the condition of dentin, root canals, periodontium, and blood vessels.
Panoramic (OPTG, orthopantomogram). It is a detailed flat image of the jaws, teeth, joints, and sinuses. This image helps to detect carious areas, defects in fillings, impacted teeth, and cysts. And also draw up a correct plan for implantation, prosthetics, and treatment.
Occlusal. This is the so-called bite radiography, which is often used when examining children, as well as when it is impossible to obtain clear results using targeted radiography.

In addition, photographs can be film or digital, when the resulting image is transmitted using a special sensor to a computer monitor. In the second case, the study is called radiovisiography.

What can an x-ray reveal?

Thus, using dental x-rays, the dentist can determine:

inflammatory processes inside the tooth that are invisible during normal examination;
presence, size and location of neoplasms (eg, cysts) or foreign bodies;
quality of dental canal filling;
the degree of development of caries and the presence of deep, hidden carious areas;
the presence of an abscess or other purulent-inflammatory processes;
cracks in teeth;
abnormalities in bone development;
the presence of hidden, unerupted teeth (for example, wisdom teeth).

Indications for use

Dental radiography is used for two main purposes: to diagnose and evaluate the quality of treatment performed.

Allows you to detect the following diseases:

hidden carious lesion;
pulpitis (inflammation of the neurovascular bundle of the tooth);
cyst at the roots of the teeth;
periodontitis (purulent inflammation of the tissue between the root of the tooth and the hole in which it is located);
gum disease, in which bone tissue atrophies (periodontitis, periodontal disease);
neoplasm.

Intraoral radiography also helps evaluate the results of procedures such as:

root canal filling;
treatment of periodontal diseases.

Features of the appointment of dental x-rays

If you are a new patient, you will likely undergo dental x-rays so that the new dentist can get a clear picture of your dental health. This is especially important if you do not have x-rays from your previous dentist. Children may need dental x-rays more often than adults because their dentists need to monitor the growth and development of their teeth. This is important because it can help the dentist determine whether baby teeth need to be removed to prevent complications, such as adult teeth growing behind baby teeth.

Kinds

Contact (pariapical)

It is carried out to obtain an image of the tooth in its true size - from the crown to the root and the hole in which it is located. As a rule, it is used to diagnose pathologies in the area of the tooth root. It also allows you to detect abnormalities in the structure of bone tissue. It is worth noting that this technique is ineffective if it is necessary to examine the condition of periodontal tissues.

When performing contact radiography with a conventional X-ray machine, film sizes of 2x3, 3x4 cm, 5x6 and 6x8 cm are used.

Interproximal

Justified in cases where it is necessary to obtain a clear and undistorted intraoral image to diagnose interdental or cervical caries and determine the degree of bone tissue resorption. Three or four photographs are taken to examine all teeth.

Occlusal (bite)

This technique is used if there is a need to examine several teeth at once (four or more), diagnose dystopic (improperly located in the dentition) and impacted teeth, study the condition of the hard palate, salivary glands, and detect neoplasms and cysts.

Occlusal radiography has proven its effectiveness in examining the dental system in children, as well as in cases where it is not possible to use the contact method due to an increased gag reflex, jaw injuries, and TMJ dysfunction. The main difference is that a film measuring 5x6 or 6x8 cm does not fit into the patient’s oral cavity, but is fixed between the closed teeth.

Long focal length

It differs from contact in that it allows you to get a clear picture of not only periodontal tissues, but also periodontal tissue (this method is actively used in periodontology). This result is achieved by using a device with a more powerful X-ray tube.

Digital radiography (radiovisiography)

Separately, mention should be made of the technology that is based on the use of a radiovisiograph. This computer device allows you to obtain targeted images of teeth with minimal radiation doses - ten times less than conventional film X-rays.

The resulting images are immediately displayed on the computer screen and then transferred to the attending physician's office, saving time.

Images can be stored for an unlimited time, they can be copied to digital media, or sent by e-mail for consultation with other doctors.

Risks of Dental X-Rays

Dental X-rays involve radiation, however, the radiation levels are so low that it is considered safe for both children and adults. If your dentist uses digital X-rays instead of film X-rays, the risks from radiation exposure will be even lower.

Also, before the x-ray, the specialist will provide you with a protective apron to put on your chest, abdomen and pelvic area to prevent unnecessary radiation exposure to vital organs. In case of thyroid disease, a special thyroid collar may be used. Children and women of childbearing age may also wear it along with a lead bib.

Pregnancy is a contraindication for radiography. Women who are pregnant or think they may be pregnant should avoid all types of X-rays. Tell your dentist if you think you are pregnant because radiation exposure is not considered safe for the developing fetus.

Radiography

An image is taken of a small area of the jaw, more often to diagnose the condition of one tooth. It allows you to evaluate the characteristics of bone tissue, the tooth itself, the tissues around it and its root (gums, bone, ligaments).

X-rays in dentistry are used to:

diagnose hidden caries, pulpitis, inflammation or cracks of the root canals;
collect information about the dental system before implantation, prosthetics or monitor their results;
assess the volume of bone tissue during sinus lift;
check the quality of root canal treatment (must be filled without voids or pores);
assess the structure of the dental system before and after orthodontic treatment;
perform an accurate diagnosis if the patient’s complaints correspond to several diseases.

There are several types of X-rays used in dentistry.

Intraoral, dental. Performed to obtain an image of a single tooth or small area. The picture is taken using a radiovisiograph - a digital camera that captures an x-ray signal. The technology allows you to obtain high-resolution images: the doctor can see the condition of the canals, hard tissues, etc., and identify diseases at the initial stage. Radiation exposure with digital radiovisiography is minimal, which allows the method to be used for primary and intermediate diagnostics, when assessing the results and quality of treatment. The image is taken in a few minutes: a sensor is placed in the patient’s mouth on the side of the tooth being examined, and a pulsed radiation source is placed near the face. The image is available for viewing immediately.

Panoramic. It is performed to assess the structure and condition of the jaw as a whole, allows you to identify foci of inflammation or infection, pathology or disease of the TMJ, and assess the condition of the maxillary sinus and periodontium. Panoramic photographs are needed in preparation for implantation, prosthetics, and orthodontic treatment. They are performed using a special apparatus. The radiation dose is higher, but remains safe.

CT scan. It is used in planning sinus lifting, bone grafting, implantation, and other surgical interventions, and in diagnosing periodontal diseases. The photographs are taken in certain projections and used to build a three-dimensional model of the jaw. Computed tomography is very informative. The study provides information about the localization of inflammation (including intraosseous), the presence of tumor-like formations, their structure, size, features of the location of the root canals, etc.

Preparation and carrying out the procedure

Dental X-rays do not require special preparation. The specialist will guide you through each step of the x-ray process. He may leave the room briefly during filming. You will be required to stand or sit still for short periods of time. Spacers (film holders), if used, will move and adjust in the mouth to produce correct images.

Once the images are ready—immediately in the case of digital x-rays—your dentist will check them and determine whether or not there are any abnormalities.

Are dental x-rays safe for human health?

In accordance with SanPiN 2.6.1.1192-03, the maximum permissible annual radiation dose during diagnostic x-ray procedures is 1000 μSv (microsievert) for an adult and 300-400 μSv for a child.

To receive it, within a year you must complete:

500 targeted dental examinations using a radiovisiograph;
100 procedures of conventional x-rays with image output on film;
80 digital or 40 film orthopantomographies (obtaining a panoramic image).

Thus, dental X-rays for almost any purpose do not exceed the permissible doses. Therefore, it does not have a negative effect on health. Even when producing film OPTG, the radiation dose is a maximum of 30 μSv. If it is necessary to take a targeted X-ray of the teeth and use radiovisiography, you can even get several images during one appointment. Without any risk to health, since a single dose in this case is only 2-3 μSv.

Digital radiography

Today there is a new technique for dental radiography using digital technology. The new method eliminates the need to develop X-ray film in a dark room; instead, the X-rays are sent directly to a computer and can be viewed on screen, saved or printed. There are several advantages of using this technology:

minimal radiation;
saving time - the image is available on the screen a few seconds after shooting is completed;
the ability to enlarge images multiple times compared to their actual size on the computer screen;
the ability to send images by email (for example, to another specialist to get a second opinion, etc.);
software installed on a computer can help dentists digitally compare current images with previous ones in the process of subtraction radiography. Using this technique, everything that is similar between two images is "subtracted" from them, leaving a clear, detailed image of only the part that is different. This helps dentists easily see subtle changes that might not be immediately noticeable.

Dental radiography is of fundamental importance for correct diagnosis. Thus, today radiography is an integral and extremely important part of professional dental care.

Radiology in dentistry

Lateral photographs of the skull are taken as a mandatory addition to direct ones. However, it is quite difficult to study the condition of the bones of the facial skeleton from these photographs due to the summative effect of the right and left halves of the skull. Usually only gross, extensive bone changes are visible. Lateral photographs are often performed to examine the condition of the skull, its base, sella turcica, sphenoid and frontal sinuses, as well as to determine the location of foreign bodies.

Axial and anterior semi-axial photographs are performed if it is necessary to examine all structures of the base of the skull, bones of the midface, including the orbits, maxillary sinuses, and zygomatic bones.

Extraoral (extraoral) photographs of the jaws are performed using both dental and other X-ray machines. X-ray film and appropriate cassettes with intensifying screens are used. Extraoral radiographs are performed to study the lower jaw, zygomatic bones, temporomandibular joint (TMJ), as well as for sialography and fistulography. Indications for such images may be inflammatory, tumor, traumatic injuries of the jaws, extensive cysts, periodontal lesions of the lower jaw when it is impossible to perform intraoral radiographs. To study the condition of the TMJ, special installations according to Schüller and Parma can be used. Pictures must be taken on both sides to compare the joints.

Intraoral radiography continues to be the mainstay of radiographic evaluation for most dental and periodontal diseases. Currently, there are four methods of intraoral radiography used to study the condition of teeth, para- and periodontal tissue:

Contact radiography according to the isometric rule.
Interproximal radiography.
Bitewing radiography (occlusal).
Radiography with increasing focal length using a parallel beam of rays (long-focus radiography).

In recent years, a new branch of radiation diagnostics has emerged - digital radiography, which is not so much an independent method of X-ray diagnostics as a progressive modification of the transformation of the energy of the X-ray beam. If in classical radiography the radiation receiver was X-ray film, then in digital radiography these are highly sensitive sensors that directly form a digital image (direct digital radiography), or electro-optical converters that create an analog video signal, which is later converted into a digital signal using an analog-to-digital converter signal. The digital code is then processed by a computer and transformed again into a visible (analog) image on the monitor screen. Computer information processing allows you to improve image quality by manipulating contrast, brightness, clarity, size, eliminating technical errors, and highlighting areas of interest. The advantages of digital radiography are also a significant reduction in radiation exposure (tens of times), economic costs (since expensive X-ray film is not used), and the possibility of archiving information. The principle of digital information processing is also used in computer, magnetic resonance imaging and in some modes of ultrasound diagnostics. Currently, digital radiography has become the leading method of radiological diagnostics.

Dental clinics use a dental cone-beam tomograph GXCB-500 from GENDEX (USA) and equipment from SIRONA (Germany). Together with the Heliodent Vario dental X-ray device, the Sirona Sidexis visiograph is used here, which also allows you to significantly reduce the radiation exposure to a person: the touch sensors that radio visiographic systems are equipped with are 10 times more sensitive than X-ray film!

Also, ORTHOPHOS XG 5 DS is widely used - a digital X-ray device, which is designed for panoramic and tomographic imaging of the entire jaw, as well as the temporomandibular joints and paranasal sinuses, it is indispensable for implantology, prosthetics and orthodontics. A panoramic photograph of the teeth is taken with this device in a few seconds, and the radiation dose is so insignificant that it is recommended for use in pediatric dentistry.