Dental X-rays are a common part of oral healthcare. These imaging tools are a valuable part of dental care, allowing dentists to see what is not visible during a routine examination. Modern dental practices prioritize patient safety through advanced technology and careful protocols. This article clarifies how dental X-rays are used safely and how their frequency is determined.
Understanding Dental X-rays
Dental X-rays, also known as radiographs, are internal images of teeth and jaws used to evaluate oral health. They help identify problems like cavities, bone loss, impacted teeth, and other issues not visible during a visual examination. They can detect small areas of decay between teeth or beneath existing fillings, and bone loss due to periodontal disease.
Modern dental X-rays use very low levels of radiation. A single digital dental X-ray exposes a patient to about 0.005 millisieverts (mSv) of radiation, roughly equivalent to a few hours of natural background radiation. The average person is exposed to about 3.0 mSv annually from natural sources like cosmic rays, radon gas, and radioactive materials in the earth. The shift from traditional film to digital radiography has significantly reduced radiation exposure by up to 80-90%, making modern dental X-rays much safer.
Determining X-ray Frequency
There is no fixed, universal number of dental X-rays considered safe in a year, as the frequency is highly individualized. Dentists determine the need for X-rays based on a patient’s clinical situation, oral health history, and risk factors. These factors can include a history of cavities, periodontal disease, growth and development in children, or existing dental restorations.
Professional guidelines from organizations like the American Dental Association (ADA) recommend taking X-rays only when diagnostically necessary, adhering to the ALARA (As Low As Reasonably Achievable) principle. This principle means radiation exposure should be kept as low as possible while still obtaining necessary diagnostic information. For some adults with good oral health and low risk of dental disease, this might mean bitewing X-rays every 18 to 36 months, while children or individuals with higher risk factors might require them more frequently, perhaps every 6 to 24 months to monitor developing teeth and detect issues early. The decision to take X-rays is a professional judgment, weighing diagnosis benefits against minimal radiation risks.
Minimizing Exposure and Specific Scenarios
Dentists use various measures to minimize radiation exposure during dental X-rays. These include using digital sensors, more sensitive and require less radiation than traditional film, and precisely targeting the X-ray beam to the area of interest. Historically, lead aprons and thyroid collars were commonly used to shield sensitive areas of the body, absorbing 90-95% of scattered radiation. However, recent recommendations from the ADA no longer advise the routine use of lead aprons and thyroid collars for patients, as modern digital X-ray equipment and beam restriction provide sufficient protection, and shields can sometimes obstruct the image, leading to retakes.
For specific patient groups, safety considerations are made. Children often require X-rays to monitor growth and development of teeth and jaws, detect cavities, and assess for impacted teeth. While children’s developing bodies are more sensitive to radiation, pediatric X-ray doses are very low, and dentists prioritize minimizing exposure, taking X-rays only when clinically necessary. For pregnant individuals, dental X-rays are considered safe when necessary, with proper shielding, as radiation is very low and not considered harmful to the pregnant person or baby. While elective X-rays might be postponed until after pregnancy, necessary diagnostic imaging for urgent dental issues should not be delayed.