X-Rays/Radiographs

Dentists use X-rays to help diagnose damage and disease that is not visible during a regular dental examination. How often X-rays, or radiographs, should be taken depends on specific factors such as an individual’s current oral health, age, risk for disease and any signs or symptoms of oral disease. This means that there is no “one size fits all” when it comes to the interval between dental X-rays. The “ALARA” principle, a phrase developed in the 1970s by the International Commission on Radiologic Protection that stands for “As Low as Reasonably Achievable,” means taking precautions 1 to help ensure that:

• all X-ray exposures are justified in relation to their benefits;
• necessary exposures are kept as low as reasonably achievable (i.e., ALARA); and
• the doses received by patients and personnel are kept well below the allowable limits.

The ADA encourages dentists and patients to discuss dental treatment recommendations, including the need for X-rays, in order to make informed decisions together. Additionally, an expert panel convened by the ADA Council on Scientific Affairs developed evidence-based clinical recommendations on radiation protection and regulatory considerations in dental imaging. 2

In 2012, the ADA, in collaboration with the U.S. Food and Drug Administration (FDA), developed recommendations for dental radiographic examinations to serve as an adjunct to the dentist’s professional judgment of how to best use diagnostic imaging. 3 Radiographs can help the dentist evaluate and definitively diagnose many oral diseases and conditions. However, the dentist must weigh the benefits of taking dental radiographs against the risk of exposing a patient to X-rays, the effects of which accumulate from multiple sources over time. The dentist, knowing the patient’s health history and vulnerability to oral disease, is in the best position to make this judgment. For this reason, the recommendations are intended to serve as a resource for the practitioner and are not intended to be standards of care, nor requirements or regulations.

Radiation dosage is expressed as effective dose, a term applied to the weighted sum of doses to tissues that are sensitive to radiation. This number is derived by calculation. Effective dose as a unit of measurement was devised by the International Commission on Radiological Protection in 1990, and the method of calculation was updated in 2007. 4 Effective radiation doses for select dental and medical radiographic examinations are listed in Table 1 of the 2024 ADA-convened expert panel report on radiation protection. 2

Radiation exposure associated with dental imaging represents a minor contribution to the total exposure from all sources. The National Council on Radiation Protection and Measurements (NCRP) has estimated that the mean effective radiation dose from all sources in the U.S. is 6.2 millisieverts (mSv) per year, with about half of this dose (i.e., 3.1 mSv) from natural sources (e.g., soil, radon) and about 3.1 mSv from man-made sources. 5 About half of the man-made radiation exposure is related to computed tomographic (CT) scanning. Overall, dental imaging accounts for less than 1 percent of the estimated collective annual effective dose received from medical imaging, such as CT scans, interventional radiology and other procedures. 6

A new report published online ahead of print in The Journal of the American Dental Association (JADA) offers updated recommendations on radiation protection in dental radiography and cone beam computed tomography (CBCT) from an expert panel established by the ADA Council on Scientific Affairs. 2 The recommendations update previous guidance on radiographic safety issued by the ADA and FDA in 2012 3 and are intended to help clinicians implement appropriate imaging practices that provide optimal information to diagnose and support management of oral health conditions while protecting patients and dental professionals from unnecessary exposure to ionizing radiation.

One of the most notable changes in this update is that thyroid collars (shields) are no longer recommended for any imaging procedures in dentistry. Thyroid collars and other shielding, such as lead aprons, can block the primary X-ray beam, which may result in the need for additional radiographs being taken. Patients can be more effectively protected from unnecessary radiation exposure through proper use of rectangular collimation (i.e., restricting the X-ray beam to the area of interest), making sure patients are properly positioned so the best radiograph can be taken, and implementing appropriate dose-reduction procedures.

These recommendations on patient shielding align with the American Academy of Oral and Maxillofacial Radiology’s recent position statement on patient shielding during dental imaging. 7

Other recommendations for minimizing exposure to radiation in dentistry include:

• Ordering radiographs based on clinical need and making a good-faith attempt to use radiographs acquired at from previous dental exams;
• Using digital receptors instead of conventional film for imaging;
• Restricting the x-ray beam’s size to the area that needs to be examined (an approach called rectangular collimation);
• Incorporating CBCT only when lower-exposure options will not provide the necessary diagnostic information;
• Adhering to all applicable federal, state and local regulations on radiation safety. 2

The ADA has joined with more than 80 other health care organizations to promote Image Gently, an initiative to “child size” radiographic examination of children in medicine and dentistry. 10 Providers are urged to:

• select X-rays for individual needs, not as a routine;
• use the fastest image receptor available;
• use cone-beam CT (CBCT) only when necessary;
• collimate the beam to the area of interest;
• “child-size” the exposure time. 9

Similar to Image Gently, Image Wisely is a program to limit X-ray exposure in adults to only that which is needed.

State laws and regulations set specific requirements for the use of ionizing radiation, including X-rays. The radiation protection program in your state may provide specific requirements for:

• Inspection and testing for the facility, X-ray machine, radiation monitoring equipment and radiograph processing equipment
• Permits or licensing
• Supervision of personnel
• Use of dosimetry badges
• Training or certification
• Dental office design and use of protective shielding
• Record keeping
• Equipment

Radiographic training requirements for dental office personnel frequently differ from and are less rigorous than those for medical personnel who take medical X-rays. Training requirements for dental office personnel typically are found in state dental practice acts or dental board regulations.

The risk of occupational exposure in dental settings is far lower than that in hospitals and medical offices. According to the NCRP, 10 the occupational exposure limit is 50 mSv in one year, although, lifetime occupational effective dose is limited to 10 mSv times the number of an individual’s age. The NCRP concludes that occupational exposure for dental personnel shall not exceed these limits, excepting for problems associated with facility design, diagnostic equipment performance, or operating procedures. For pregnant dental personnel, the radiation exposure limit is 0.5 mSv per month (see following section). 11

The recent expert panel report on radiation protection recommends the use of dosimeters and work practice controls for pregnant dental staff who work with X-rays. 2 Studies of pregnant patients receiving dental care have affirmed the safety of dental treatment. 12, 13

The digital era of dental radiography began in 1988 with RVG – radio/visio/graphy. 14 The first film-like sensor was introduced in 1994. In addition to a reduction in exposure, digital radiography enables efficient communication of electronic information, provides portability, 15 and eliminates the environmental burden of silver and chemicals used to develop X-rays. One of the concerns associated with digital radiography is that in an effort to diminish the appearance of image “noise,” the individual taking the radiograph may increase the dose of X-ray exposure. Sometimes termed “exposure creep,” manufacturers are building tools into equipment to provide methods other than increasing dose to improve detector sensitivity. 16

Cone-beam computed tomography (CBCT), introduced in the U.S. in the late 1990s, produces a three-dimensional image of maxillofacial structures, with uses in oral surgery, orthodontics, and endodontics. The scanner rotates around the patient’s head producing up to 600 images, which are assembled or reconstructed by scanning software. Analogous to a 2-D image comprised of pixels, CBCT creates a 3-D image comprised of voxels. One drawback of CBCT imaging is the radiation exposure it requires. CBCT in dentistry is the major single contributor of diagnostic radiation, and recent publications have expressed concerns regarding the safety of this imaging procedure in children. 9 The 2024 report 2 from ADA-convened expert panel recommends that “clinicians should only perform radiographic imaging, including CBCT, after reaching the professional judgment that there is a clear clinical benefit from the imaging exam, and that this benefit outweighs the risks associated with exposure to ionizing radiation. The benefits and associated risks of the dental imaging exam should be clearly discussed with the patient. Justification should also be based on consultation of evidence-based selection and recall criteria balanced with risks of exposure.” 2 Recommendations from regulatory agencies such as the FDA 17 provide guidance regarding strategies to maximize imaging safety and efficacy.

Hand-held units, which facilitate imaging when patients are sedated or anesthetized, were approved by the FDA in July 2005. The FDA advises dentists 18 to use devices legally marketed for this purpose, checking to see that they are properly labeled to indicate that this is the case. Studies of legally marketed devices find that radiation exposure is within safety limits 18, 19 and, in fact, are significantly less than for wall-mounted systems (0.28 mSv vs. 7.86 mSv). The studies concluded, therefore, no need for additional shielding. 19

Radiographs in Diagnosis (Trans.1974:653)

Resolved, that the House of Delegates reconfirms that a diagnosis and treatment plan cannot be made from radiographs alone. Benefits shall not be determined solely on the basis of radiographic evidence.

American Dental Association
Adopted 1974

Delegation of Radiographic Film Exposure (Trans.1982:534)

Resolved, that the American Dental Association, in the public interest, supports the principle that dentists who choose to delegate the taking of radiographic films should delegate the function to personnel who have had a structured course in such procedures, and be it further

Resolved, that a structured course in radiography is defined as a planned sequence of instruction of specified content, designed to meet stated educational objectives and to include evaluation of attainment of those objectives.

American Dental Association
Adopted 1982; Reviewed 2018

Inclusion of Radiographic Examinations in Dental Benefits (Trans.1991:634)

Resolved, that in working with plan purchasers, health benefits consultants and third-party payers, the American Dental Association stress the importance of including, as part of a comprehensive dental benefits program, radiographic examinations in patient diagnosis and treatment when indicated, as determined by the treating dentist.

American Dental Association
Adopted 1991; Reviewed 2016

Dental Radiographs for Victim Identification (Trans.2003:364; 2012:442)

Resolved, that the ADA promote to practicing dentists the importance of providing, as permitted by law, radiographs, images and records on patients of record that are requested by a legally authorized entity for victim identification and which will be returned to the dentist when no longer needed, and be it further

Resolved, that copies of these records should be retained by dentists as required by law.

American Dental Association
Adopted 2003; Amended 2012; Reviewed 2017

Guidelines on Capture and Use of Diagnostic Images by Dentists, and by Third-Party Payers or Administrators of Dental Benefit Programs (Trans.1995:617; 2007:419; 2016:284)

Resolved, that the following guidelines pertain to dentists:
1. Dentists should refer to the joint ADA/FDA publication titled DENTAL RADIOGRAPHIC EXAMINATIONS: RECOMMENDATIONS FOR PATIENT SELECTION AND LIMITING RADIATION EXPOSURE, or its successors, for assistance in determining clinical necessity for such diagnostic imaging.
2. If a third party requests an image which was not generated as part of the dentist’s clinical treatment, dentists should consider the clinical necessity of the image in connection with the request.
3. When a dentist determines that it is appropriate to comply with a third-party payer’s request for images, submit a duplicate set and retain the originals.
4. Postoperative images should be required only as part of dental treatment.
5. Images must be correctly identified and be of diagnostic quality.
6. Images are an integral part of the dentist’s clinical records and are considered the dentist’s property, consistent with state law.
7. The confidentiality of images and all other patient record content must be maintained in accordance with applicable HIPAA and state privacy and security regulations.
8. Additional costs incurred by the dentist in copying images and clinical records for claims determination that are not reimbursed by the third-party payer may be billed to the patient. And be it further

Resolved, that the following guidelines pertain to third-party payers and dental benefit plan administrators:
1. Payers and administrators should refer to the joint ADA/FDA publication titled DENTAL RADIOGRAPHIC EXAMINATIONS: RECOMMENDATIONS FOR PATIENT SELECTION AND LIMITING RADIATION EXPOSURE, or its successors, for assistance in determining their necessity for such diagnostic imaging. Third-party payers should not request that images be generated solely for administrative purposes.
2. All images, including duplicates, except those submitted in digital or other electronic form, and whether or not it has been requested, should be returned to the dentist.
3. It is improper for third-party payers to deny authorization for payment or make determinations about treatment based solely on images.
4. Third-party payers should not use images to infringe upon the professional judgment of the treating dentist or to interfere in any way with the dentist/patient relationship. All questions of interpretation of images must be reviewed by a dentist consultant.
5. Clinical images should only be requested when they will be reviewed by a dentist to make a determination regarding the patient’s entitlement to benefits. Dentists reviewing images for this purpose should be licensed in the U.S., preferably within the jurisdiction of the dentist providing the images in accordance with applicable state law.
6. Patients should be exposed to radiation only when clinically necessary, as determined by the treating dentist. Postoperative images should be required only as part of dental treatment.
7. Third-party payers must protect all images submitted by dental offices in accordance with applicable HIPAA and state privacy and security regulations.
8. All images submitted to third-party payers should be returned to the treating dentist within fifteen (15) working days. Images received in an electronic form should be permanently deleted within 30 days of the completion of claims adjudication.
9. Where a claim or predetermination request indicates that images are provided, the third-party payer should immediately notify the submitting dentist’s office if the images are missing.
10. A patient’s predetermination request or claim should not be prejudiced by the third-party payer’s loss or misplacement of images.
11. As it is necessary for a dentist to maintain accurate and complete records, third-party payers should accept copies of images in lieu of originals.
12. Any additional costs incurred by the dentist in copying images and clinical records for claims determination should be reimbursed by the third-party payer.

American Dental Association
Adopted 1995; Amended 2007, 2016