Why x-rays?

A common question that patients ask the dentist during their child’s preventative visit is “why do I need x-rays?”  Some patients are concerned with the radiation associated with dental x-rays or may think that too many need to be taken. The risks of not taking x-rays far outweigh the small amount of radiation that the patient is exposed to when having the x-ray taken.

The main types of dental x-ray include the periapical (PA), bitewing (BW), and the panoramic x-ray. The periapical is used to detect decay in the anterior or front teeth, as well as checking the roots of anterior or posterior teeth for signs of infection. A bitewing is an x-ray that shows decay in between the posterior teeth that may not be visible with the naked eye. The bitewing also shows whether there has been any bone loss in between teeth and is helpful in diagnosing periodontal (gum) disease. Both the bitewing and periapical x-ray are crucial for any procedure that needs to be completed, by showing the dentist how close he or she is to the nerve of the tooth. A panoramic x-ray is a 2D representation of the jaws and is useful in checking the formation of teeth, screening for various diseases of the jaw, and checking the health of the bony part of the temporomandibular (jaw) joint. Together, the three types of x-rays with a thorough clinical exam give the dentist an overall picture of the patient’s oral health and form a good baseline to compare back to in subsequent visits.

Among medical uses, dental x-rays expose the patient to less radiation than almost any x-ray that can be taken. According to the American Dental Association, a bitewing and periapical x-ray both deliver .005 millisieverts of radiation, whereas a panoramic x-ray delivers .01 millisieverts. For comparison, an x-ray of the upper G.I. tract delivers 6.0 millisieverts, over 1,200 times more than a bitewing or periapical. Per the CDC, a domestic flight in the United States delivers roughly the same dose of radiation (.004 millisieverts) as a dental x-ray.  Every day, you are exposed to background radiation, which is made up of cosmic radiation from the sun and stars, radiation from radioactive materials naturally found on our planet, and a small percentage from man-made sources such as a nuclear power plant.

In the above chart, dental x-rays fall under the category of conventional radiography/ fluroscopy and thereby contribute to less than 5% as a source of radiation exposure. Dental x-rays are considered safe and make up a very small portion of the radiation that a person is exposed to on a yearly basis.

As a new patient in a dental office, it’s important to have proper x-rays taken that serve as a baseline for comparison in the future. Every dentist has an opinion on how often radiographs should be taken, and it is an important discussion to have with any individual patient. If you are concerned about radiation, it’s okay to express these concerns with the dentist. However, it is nearly impossible to form accurate diagnoses of tooth decay, gum disease, or pathology of the jaws without basic dental x-rays. Dental offices are checked regularly to make sure they are in compliance with proper x-ray safety and regulations. Dental assistants and dentists do everything they can to protect the patient and minimize radiation. X-rays are a preventive measure that may catch many pathologies of the mouth at an early time. With early intervention, you can maintain more tooth structure, halt bone or gum loss, and detect malignancies before they spread. In some instances, dental x-rays may show cavities that are forming, which are invisible to the human eye, and can still be halted if the proper measures are taken. In conclusion, dental x-rays are a safe procedure that has many benefits, with very little risk.