When you take an x-ray, you are not really getting a picture of your insides; rather, you are getting a shadow of your insides.

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Why do I need dental x-rays?

Dental x-rays (or radiographs) show your dentist or radiologist the inside of your teeth and bones. These areas are not visible in any other way. Radiographs allow early detection of oral health problems by providing information that helps diagnose dental decay, periodontal disease, and infections in your jaws. This information provides dental practitioners with the best available options for treatment.

How often do I need x-rays of my teeth and jaws?

The frequency of dental x-rays (or radiographs) is dependent on several factors, including your current oral health, your risk for dental decay and periodontal disease, and whether you have any symptoms. Your dentist considers these factors when prescribing dental x-rays. Furthermore, the American Dental Association and Food and Drug Administration have created best practices for determining the frequency of x-rays. Radiographs are recommended once or twice a year for those at higher risk for caries (cavities) or other oral disease complications.

Are dental x-rays safe?

Creating dental x-ray images uses low levels of x-radiation. The risks from these low levels of radiation exposure are relatively minimal. Nevertheless, your dentist will minimize the amount of radiation you receive using various methods, including using digital technology, customizing the x-ray machine settings to your jaw size, and protecting you with thyroid collars and lead aprons as appropriate.

What are the different types of dental x-rays?

There are two categories of dental x-rays: intraoral and extraoral. The most common intraoral radiographs are bitewing and periapical x-rays. Extraoral radiographs called Panoramic and Cone Beam CTs are less common.

Bitewing x-rays are a type of radiograph in which the film or plastic sensor has a little tab in the middle that you bite down on with your back teeth. These x-rays show details of both upper and lower teeth in one area of your mouth and are used to detect decay between tooth surfaces and changes in bone density caused by periodontal disease. Bite-wing x-ray images are also helpful in determining how well crowns fit into place whether dental fillings have been done correctly! A good bite-wing x-ray will show the tooth’s crown down to its supporting bone structure.

Periapical x-rays show the whole tooth – from the crown to beneath where it is anchored in your jaw. Each periapical radiograph only indicates two to three teeth on the upper or lower jaw. This image detects abnormalities or infections in your root structure and surrounding bone.

Panoramic x-rays use a machine that rotates around the outside of the head. This single x-ray image shows the structures of the entire mouth, including all teeth and jawbones and the position of fully emerged and emerging teeth. It identifies impacted teeth and aids in identifying and diagnosing tumours.

Cone Beam CT scans are similar to a medical CT scan in that it produces a three-dimensional (3D) image. The 3D imaging provides details on dental structures, soft tissues, nerve paths and bones in the craniofacial region, thereby providing greater precision in diagnosis and treatment planning of many dental and jaw diseases. A cone beam CT scan is a necessary diagnostic tool when regular dental or facial x-ray images can’t provide sufficient information. 

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Benefits

A dental radiograph is an image your dentist uses to assess the health of the hard tissues (teeth and bones) of your mouth and surrounding facial structures. Radiographs enable dentists to detect cavities forming between teeth or under restorations (fillings), bone disease, periodontal disease, infections developing under the gums, or even tumours. A dental radiograph can also evaluate any injury to your mouth to aid the dentist in diagnoses and treatment. It can also reveal developmental problems in children or diseases before they become serious medical issues! Early detection of any defect or infection will not only limit permanent damage but will also prevent other areas of the body from being affected.

Dental x-rays are an essential diagnostic tool for detecting damage and disease not visible during an oral dental exam. The frequency that x-rays should be used depends on present oral health, age, the risk for disease and any signs of oral diseases like tooth decay. Children might need more frequent x-rays than adults because their teeth and jaws are still developing, while adults’ teeth may suffer from tooth decay less frequently. Your dentist will review your history, examine your mouth then decide if you need x-rays or not.

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Safety

The amount of radiation used in dental radiology is very minimal as dentists follow the ALARA principle, “As Low As Reasonably Achievable,” when obtaining radiographs. This principle means they will only use as much radiation as needed to see what is going on with your teeth and care for them. We are all exposed to small amounts of “background radiation” from various sources every day, including the sun, soil, rocks, buildings, and even air and water. Every year, the average Canadian’s background radiation exposure is about 3.2 millisieverts (mSv, a unit of measure). By comparison, a bitewing exam (two or four images) exposes you to about 0.005 millisieverts, similar to one or two days of background radiation.

Dental x-rays are safe but require low levels of radiation exposure to work. Dental x-ray tools and techniques take every precaution to keep the risk of potentially harmful effects at a minimum, including using a lead apron or thyroid collar to shield the abdomen or thyroid against radiation.

If you are a new patient, your dentist may recommend x-rays to measure the present status of your oral health and create a baseline for future identification of changes. New x-rays may be needed to help detect any new cavities or evaluate the growth and development of teeth. If previous dentists have taken any radiographs of you, your current dentist may ask for copies of them, thereby eliminating unnecessary radiation exposure.