Understanding the Radiation from Dental X-Rays and CBCT Scans

When discussing dental X-rays and Cone Beam Computed Tomography (CBCT) scans, the question of radiation exposure often arises. While the radiation from these procedures is minimal, it is important to understand the context and health implications. This article delves into the radiation levels involved and provides a comparative analysis to help alleviate concerns.

Types of Dental X-Rays and Their Radiation Levels

Bitewing X-Rays:Approximately 0.005 to 0.01 mSv per exposure. Periapical X-Rays: Approximately 0.005 to 0.01 mSv per exposure. Panoramic X-Rays: Typically expose a patient to about 0.01 to 0.02 mSv. Cone Beam CT (CBCT) Scans: Deliver a higher dose ranging from 0.05 to 0.2 mSv or more, depending on the specific settings and area being scanned.

These doses are compared to other sources of radiation to put them in perspective:

Twenty dental X-ray exposures are equivalent to living in Denver, Colorado, for two months, where there is one mile less air to shield residents from ionizing cosmic rays from space. Twenty X-rays are also comparable to flying in a jet airliner for twelve hours, primarily due to cosmic ray exposure.

Context and Comparison

It is important to consider the context of radiation exposure. According to the National Council on Radiation Protection and Measurements (NCRP), the average radiation dose per person per year in the U.S. is 6.2 mSv. The International Commission on Radiological Protection (ICRP) recommends a maximum limit of 20 mSv per year, with an average annual dose over five years not exceeding 20 mSv.

In comparison, the benefits of dental X-rays or CBCT scans often outweigh the risks. These imaging techniques are used primarily for the diagnosis and treatment of dental conditions.

Are Dental X-Rays Necessary?

Your dentist performs dental X-rays, including CBCT scans, only when necessary for the diagnosis or treatment of dental disease. The most common types of X-rays include:

Bite-wing X-Rays:Focus on the upper and lower back teeth to check for cavities between teeth. Periapical X-Rays:Show the entire length of a tooth from crown to root, used to check for the health of the bone that supports the teeth, abscesses, tumors, and impacted teeth. Occlusal X-Rays:Show the nearly full arch of teeth in either the upper or lower jaw, used to check for extra teeth, fractures, unusual growths, or foreign objects. Cephalometric X-Rays:Show a side of the face to view the teeth, jawbone, and soft tissues, mostly used by orthodontists. Panoramic X-Rays:A two-dimensional X-ray exam that shows the entire mouth in a single image, including teeth, jaws, and surrounding structures. Cone Beam CT (CBCT) Scans:A 3-D image of the teeth, soft tissues, nerve pathways, and bone, used by oral surgeons and orthodontists for treatment planning and dental implant placement.

The minimal radiation exposure from dental X-rays is well-documented and scientifically justified. These imaging techniques play a crucial role in diagnosing and treating dental conditions.

How Much Radiation Are You Exposed to and Is It Safe?

X-ray radiation is measured in Sieverts (Sv), but most measurements are performed in millisieverts (mSv). The average daily exposure to radiation from natural sources such as minerals in the ground, sunlight, and medical procedures (including dental X-rays) is typically minimal.

For perspective, a typical dental X-ray is equivalent to:

Living in Denver, Colorado, for two months. Flying in a jet airliner for twelve hours.

The maximum acceptable radiation dose for the public, as recommended by ICRP, is 20 mSv per year. This is a threshold for long-term safety and health.

In Summary: While dental X-rays and CBCT scans do involve some radiation exposure, they are generally low and considered safe when used appropriately. The benefits of these imaging techniques in diagnosing and treating dental conditions far outweigh the minimal risks. Always consult your dentist or oral health professional regarding the specific risks and benefits associated with these imaging techniques.