Dental Radiography is a highly specialised field and used by every modern dental practice.

A radiograph is an exposed and processed film also known as an x-ray negative. They are pictures of the teeth, bones, and surrounding soft tissues and they are made to identify possible problems with the teeth, mouth, and jaw.

X-rays can detect cavities, hidden dental problems, and bone loss that cannot be seen during a visual examination. Dental X-rays may also be done before treatment or as follow-up after dental treatment.

Due to the hazards of being exposed to radiation, dental radiographic specialists must know the procedures necessary to produce radiographs of diagnostic quality. They must also have a thorough knowledge of the hazards associated with the use of radiation, and how to protect their patients and themselves against those risks.
 
A dental x ray is essential for virtually all dental procedures. To produce suitable diagnostic radiographs the radiographer requires specialist knowledge of the teeth and oral cavity, as well as types of dental film, exposure settings, processing techniques, use of darkroom, and health and safety.

Dental film is supplied in different sizes and degree of sensitivity and each type of film has different exposure requirements in order to produce suitable radiographs for diagnostic purposes. The methods used in processing x-ray films also have to be followed precisely in order to obtain good results.
 
Most radiographs are made on intraoral film. This is when the exposure is made with the film held firmly in the mouth. Extraoral are taken from the outside of the mouth. As intraoral x-rays are taken in closer relation to the teeth they give more detail and less superimposition of shadows.

Panoramic radiographs are used to show a continuous view of the teeth, jaws and gums. This type of radiograph is used by the military and used for the inital dental processing of military personnel. The advantages of panoramic radiography is that it gives a bilateral view of the dental cavity as well as a lower radiation dose to the patient.The disadvantage is that it is not as detailed as intraoral x-rays and therefore can overlook smaller caries and abnormalities. Panoramic radiographs are used for diagnosing diseases, surveying for fractures, etc…

A radiographic image shows light and dark areas depending on the density of the material that the x-ray penetrates. Teeth appear lighter because less radiation penetrates them to reach the film. Cavities, decay, and other changes in the bone density appear darker because X-rays penetrate them easily. Fillings, and other dental work may appear lighter or darker, depending on the density of the material used.

The radiation dose of an X-ray received by a dental patient is typically small. A lead shield, lead apron, and sometimes with a lead collar are used to reduce the patient’s exposure to radiation. The dental specialist reduces their exposure to radiation by going out of the room or by standing behind protective material when the X-ray is taken.

Basic Procedure for dental radiography

The basic procedure for taking a dental x-ray is to sit the patient down and adjust the headrest so that their head is in the correct position. The patient is draped with a lead apron and a collar. The film packet is inserted into the x-ray machine and the x-ray tube is aligned. The correct exposure factor is selected and the exposure is then made. The film is then sent for processing.

Under-exposed radiographs can occur if there is insufficient radiation exposure, insufficient development time, or if the developing solution is overused or too cold.

Over-exposed radiographs can occur if there is too much radiation exposure, too much development time, or if the devloping solution is too warm.

A blurred image can occur if the patient or tube moved during an exposure.

Digital Radiography

Digital x-rays, which replace the film with an electronic sensor are becoming widely used in dentistry as the technology improves. They require less radiation and processing is faster than with conventional x-rays. The results can often be seen immediately on a compuer. Digital sensors however are very expensive.

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