Category: Uncategorized

20 May 2022
dental x-ray

X-Rays and Radiation Safety Principles in Dentistry

Dental x-rays are important for maintaining an individual’s optimal oral health. Like with any x-ray procedure, there are radiation safety principles that have been put in place to protect both patients and dentistry professionals.

Why are Dental X-rays Important?

Dental x-rays are an essential part of maintaining a healthy jaw and teeth. This diagnostic tool allows dentists to take a more in-depth look at what’s going on inside a patient’s mouth. Some dental problems affecting the roots of a tooth or that exist below the gum line cannot be diagnosed through a simple visual exam.

What Can a Dental X-ray Be Used for?

Dentists use dental x-rays to diagnose a variety of dental conditions, including:

  • Gum disease
  • Cavities and tooth decay
  • Impacted teeth
  • Cysts
  • Abscesses
  • Jaw disorders
  • Sinus issues
  • Bone loss

These x-rays are also beneficial for individuals who smoke, have a history of restorative dental work, or drink an excessive number of sugary drinks like pop or juice.

Radiation Safety for Patients During Dental X-rays

Most patients will undergo at least one of two different types of dental x-rays during their annual or bi-annual visit to the dentist.  Each has its own radiation protection requirements to limit the patient’s radiation dose.

Bitewing X-rays

Bitewing x-rays are a type of intraoral x-ray. During a bitewing x-ray, the patient is required to bite down on a small tab attached to an x-ray film. There are usually 4 images taken to help dentists visualize all sides of the mouth.

Patients are usually required to wear a lead vest during a bitewing x-ray. Thyroid collars and leaded glasses can also be used to protect the eyes and sensitive areas of the throat.

Panoramic X-rays

Panoramic x-rays are extraoral x-rays used to diagnose dental problems in the jaw and skull. This 2D digital x-ray captures a single image of the entire mouth.

dental x-ray

The machine has two sides. One side houses the x-ray tube, and the other houses the x-ray detector or x-ray film. The x-ray rotates around the patient’s head during this procedure to take the full image. A lead apron or thyroid protective collar may also be worn during this procedure as a safety precaution; however, it is not required.

Miscellaneous Dental X-rays

Other types of dental x-rays a patient may experience include a dental cone beam CT scan (3D image of the teeth and jaw) or a cephalometric projection (image of the entire head). These x-rays are not likely to occur during a routine visit.

Are Dental X-rays Safe?

Patients are exposed to extremely minimal radiation doses during dental x-ray procedures. A patient who undergoes a bitewing x-ray procedure will receive a radiation dose of 0.4 mrem, while a panoramic x-ray radiation dose exposure is approximately 0.7 mrem.  

For comparison, the average U.S. citizen receives an annual radiation dose of 620 mrem. The sources of this radiation come from naturally occurring cosmic, internal, and terrestrial radiation, medical procedures like CT scans and conventional radiography procedures, and consumer products like tobacco, fertilizer, or welding rods.  

As mentioned above, there are numerous protective measures put in place to help limit overall radiation exposure. Protective measures for patients during a dental x-ray include:

  • Using protective lead aprons and thyroid collars
  • Using modern x-ray equipment and up to date imaging techniques
  • Limiting the number of images taken in a year

The American Dental Association recommends that healthy patients receive x-rays once every 2 to 3 years to limit the amount of radiation exposure they receive.

Like any diagnostic procedure, the benefits of a dental x-ray far outweigh the low radiation dose a patient will receive. Dental x-rays can not only identify existing issues, but they can also identify potential problems that, if left untreated, could turn into serious or even life-threatening issues.

Radiation Safety for Dental Professionals

Radiation safety and radiation protection guidelines are especially important for dental professionals. The NRC regulates the amount of radiation exposure for adults who work with radioactive materials. Occupational exposure limits are limited to 5,000 mrem per year.

Dental professionals including hygienists, oral surgeons, and orthodontists, are required to adhere to these exposure limits. This profession receives less ionizing radiation exposure than other healthcare professionals on average. However, basic protective measures help limit their occupational radiation exposure and keep up with ALARA standards.

Personal Dosimeter

Dental professionals should wear a personal dosimeter when operating x-ray equipment to record their dose.

Instadose+ Dosimeter

The Instadose+ dosimeter is an affordable personal dosimeter option that provides dentists and dental professionals with accurate, long-term exposure tracking. The device wirelessly captures, transmits, measures, and analyzes radiation dose exposure. Dental professionals can access their read history on-demand and in real-time thanks to the device’s Bluetooth and SmartMonitoring technology.

Unlike traditional film badges, the Instadose+ dosimeter does not need to be collected and processed off-site.

Time, Distance, and Shielding

The standard guidelines for minimizing dental professionals’ exposure are time, distance, and shielding. This means limiting the amount of time spent around a radiation source, maintaining a safe distance away from the source of radiation, and standing behind protective barriers during a procedure.

During a routine dental visit, hygienists are often the ones who prepare and take the dental x-ray. To limit their exposure from taking these images multiple times a day, hygienists will usually leave the room to increase their distance from the x-ray tube. They may also stand behind a lead wall or partition while the image is being taken.

The Takeaway

Dental x-rays are a necessary part of maintaining good oral health. Radiation safety guidelines like wearing lead vests and thyroid collars are important for limiting patient exposure during routine checkups. Wearing a personal dosimeter and following time, distance, and shielding guidelines are also necessary for limiting occupational exposure.

10 Mar 2021
Reviewing the License Regulations

A Guide to Limited vs. Broad Scope Radioactive Materials Licenses

We are often asked questions about applying for or changing licenses to possess and use radioactive materials. There are many different types of licenses; choosing amongst them can be confusing. In this post, we will discuss four common types.

US NRC logo

With some exceptions, approval by a regulatory agency (U.S. Nuclear Regulatory Commission or equivalent state agency), in the form of a license, is required to use and/or dispose of radioactive materials.

The type of license authorizing the purchase, possession, use, and disposal of radioactive materials is based on several factors:

  • Type, form and quantity of radioactive materials requested
  • Proposed use(s)
  • Experience of the proposed licensee with managing the use of radioactive materials

Types of licenses include, but are not limited to:

  • Limited scope specific academic and research and development
  • Limited scope specific medical use
  • Broad scope specific
  • Broad scope specific medical use

In this post, we will discuss the regulations under which the U.S. Nuclear Regulatory Commission (NRC) issues two common types of licenses: (i) limited scope specific and (ii) broad scope specific.  Some states, called Agreement States, have the authority under NRC regulations to issue licenses.  Their regulations are equivalent to NRC regulations.

1. Limited Scope Licenses


These licenses are issued to applicants subject the following limitations:

  • Radionuclides
  • Specified chemical and physical form(s)
  • Possession limits
  • Proposed use(s)
  • Radiation Safety Officer (RSO)
  • Authorized User(s)
  • Location(s) of use

The RSO’s training and experience should be applicable to and generally consistent with the types and quantities of licensed materials listed on the license.  Authorized users (AUs) must have adequate training and experience with the types and quantities they intend to use (NUREG 1556, Vol. 7, Rev. 1).  The applicant must submit to the regulatory agency for review and approval the specific training and experience of each proposed user and the facilities and equipment available to support each proposed use.

If the licensee wishes to change any of these limitations or add or remove an Authorized User (AU), permission must be sought from the issuing regulatory agency to amend the license. 

Medical Licenses – general comments

Licensing for the use of radioactive materials to diagnose and treat human disease is subject to more complex regulations than the academic and research and development licenses described above.  A wide variety of radionuclides and physical and chemical forms are used for a multitude of purposes in human medicine.  Consequently, AUs and the RSO must meet specific and extensive training and experience criteria focusing on the type, form, and quantity to be used as well as the intent of the use (diagnosis vs. treatment).

An AU is charged with the responsibility for (NUREG 1556 Vol. 9, Rev. 3)

  • radiation safety commensurate with use of radioactive materials;
  • administration of a radiation dose or dosage and how it is prescribed;
  • direction of individuals under the AU’s supervision in the preparation of radioactive materials for medical use and in the medical use of radioactive materials; and
  • preparation of a written directive, if required.

To be named as an AU on a medical license, the individual must satisfy one or more of the requirements outlined in Subparts D, E, F, G or H of 10 CFR 35.  In general, this requirement can be met by:

  • being board certified in a specialty medical discipline appropriate to the intended use that is recognized by the Commission or Agreement State; or
  • being named as an AU on another license issued by the Commission or Agreement State for the same or similar type, form, and quantity of radioactive materials in question; or
  • having completed training and experience as specified in the regulations.

The RSO on a medical license must satisfy the training and experience requirements outlined in 10 CFR 35.50:

  • be certified by a specialty board whose certification process has been recognized by the Commission or an Agreement State; or
  • have completed a structured educational program as outline in 10 CFR 35.50(b); or
  • be a medical physicist who is certified by a specialty board recognized by the Commission or an Agreement State, has experience with the radiation safety aspects of similar types of radioactive materials for which the licensee seeks approval and has training in the radiation safety, regulatory issues, and emergency procedures for the types of use for which a licensee seeks approval; or
  • be a medical AU, authorized medical physicist, or authorized nuclear pharmacist identified on a Commission or an Agreement State license, a permit issued by a Commission master material licensee, a permit issued by a Commission or an Agreement State licensee of broad scope, or a permit issued by a Commission master material license broad scope permittee, has experience with the radiation safety aspects of similar types of use of byproduct material for which the licensee seeks the approval and Is an authorized user, authorized medical physicist, or authorized nuclear pharmacist identified on a Commission or an Agreement State license, a permit issued by a Commission master material licensee, a permit issued by a Commission or an Agreement State licensee of broad scope, or a permit issued by a Commission master material license broad scope permittee, has experience with the radiation safety aspects of similar types of use of byproduct material for which the licensee seeks the approval.

2. Limited Scope Specific Medical Licenses


A specific license of limited scope may be issued to private or group medical practices and to medical institutions.   Each type, form, quantity and use and condition of use of radioactive materials as well as the RSO and AU(s) are named on the license (NUREG 1556 Vol. 9, Rev. 3).  These licenses may also be issued to an entity requesting authorization to perform mobile medical services and certain non-medical activities such as self-shielded blood irradiators.  Changes to any of these specifications or conditions must be requested and approved by amendment.

Research Involving Human Subjects

“Medical use” of radioactive materials includes administration to human research subjects.  A license condition authorizing such research is not required if the research is conducted, funded, supported or regulated by a Federal Agency that has implemented the Federal Policy for the Protection of Human Subjects.  Otherwise, the licensee must apply for and receive an amendment before conducting such research.  In all cases, licensees must obtain informed consent from the human subjects and prior review and approval by an Institutional Review Board.  All research involving human subjects must be conducted only with the radioactive materials listed in the license and for the uses authorized in the license (NUREG 1556, Vol. 9, Rev. 3).

Research involving human subjects may be conducted under either limited scope or broad scope specific licenses.

3. Broad Scope Specific Licenses


Broad scope specific licenses generally authorize possession and use of a wide range of radioactive materials.  Because regulatory agencies grant significant decision-making authority to broad scope licensees through the license, a broad scope license is not normally issued to a new licensee. An applicant for a broad scope license typically has several years of experience operating under a limited scope license and a good regulatory performance history (NUREG 1556 Vol. 11, Rev. 1).  Changes to the radiation safety program approved via in-house review and approval by the RSO and/or RSC (see below) do not appear on the license but are subject to review by regulatory agencies during routine inspections.

Title 10 of the Code of Federal Regulations (10 CFR) Part 33, “Specific Domestic Licenses of Broad Scope for Byproduct Material,” provides for three distinct categories of broad scope licenses (i.e., Type A, Type B, and Type C), which are defined in 10 CFR 33.11, “Types of Specific Licenses of Broad Scope.”

Type A

Type A licenses of broad scope are typically the largest licensed programs and encompass a broad range of uses.  Licensees use a Radiation Safety Committee (RSC), radiation safety officer (RSO), and criteria developed and submitted by the licensee and approved by the NRC during the licensing process to review and approve all uses and users under the license.

An applicant for a Type A broad scope license must establish administrative controls and provisions related to organization and management, procedures, record keeping, material control, and accounting and management review necessary to ensure safe operations, including:

  • establishment of an RSC
  • appointment of a qualified RSO
  • establishment of appropriate administrative procedures to ensure the following:

— control of procurement and use of byproduct material

— completion of safety evaluations of proposed uses that take into consideration adequacy of facilities and equipment, training and experience of the user, and operating and handling procedures

— review, approval, and recording by the RSC of safety evaluations of proposed uses

  • use of byproduct material only by, or under the direct supervision of, individuals approved by the licensee’s RSC

Because these controls and provisions have been established, the applicant may approve in-house, without requesting amendment:

  • Authorized Users
  • location of use within the confines of the physical location(s) listed on the license
  • changes in use of radioactive materials so long as the use is consistent with the license conditions and appropriate safety evaluations have been performed, documented, and approved by the RSC

The requirements for issuance of a Type A broad scope license are described in 10 CFR 33.13, “Requirements for the Issuance of a Type A Specific License of Broad Scope.”

Type B

Type B broad scope licensed programs are normally smaller and less diverse than Type A broad scope programs. Type B broad scope licensees use an RSO and criteria developed and submitted by the licensee and approved by the NRC during the licensing process to review and approve all uses and users under the license. Because the RSO reviews and approves all uses and users under the license, rather than a full RSC, as established for Type A broad scope programs, the types and quantities of byproduct material authorized by the Type B broad scope license are limited to those described in 10 CFR 33.11(b) and 10 CFR 33.100, “Schedule A,” Column I.  Generally, the scope of authorization for Type B licenses is limited to the experience and knowledge of the RSO.

Changes to the type, form and quantity of radioactive materials may have to be approved by the regulatory agency by amendment, depending on the specific provisions of the license.

The requirements for issuance of a Type B broad scope license are described in 10 CFR 33.14, “Requirements for the Issuance of a Type B Specific License of Broad Scope.”

Type C

Type C broad scope licensed programs typically are issued to institutions that do not require significant quantities of radioactive material but need the flexibility to possess a variety of different radioactive materials. Users of licensed material under these programs are approved by the licensee based on training and experience criteria described in 10 CFR 33.15(b). The types and quantities of byproduct material authorized by the Type C broad scope license are limited to those described in 10 CFR 33.11(c) and 10 CFR 33.100, Schedule A, Column II, again, considering the unity rule.

While 10 CFR 33.15 does not require Type C broad scope licensees to appoint an RSO, the licensee must establish administrative controls and provisions related to procurement of byproduct material, procedures, record keeping, material control and accounting, and management review to ensure safe operations. This should include the appointment of someone responsible for the day-to-day operation of the radiation safety program, such as an RSO.

Changes to the type, form and quantity of radioactive materials may have to be approved by the regulatory agency by amendment, depending on the specific provisions of the license.

The requirements for issuance of a Type C broad scope license are described in 10 CFR 33.15, “Requirements for the Issuance of a Type C Specific License of Broad Scope.”

4. Broad Scope Medical Licenses


The NRC issues specific licenses of broad scope for medical use (i.e., licenses authorizing multiple quantities and types of byproduct material for medical use under 10 CFR Part 35, as well as other uses) to institutions that (i) have experience successfully operating under a specific license of limited scope and (ii) are engaged in medical research and routine diagnostic and therapeutic uses of byproduct material (NUREG 1556, Vol. 9, Rev. 3).  Typically, these are large medical centers/teaching hospitals that have a need to administer or use a wide variety of radionuclides and/or radiopharmaceuticals for diagnosis and therapy.  Because these institutions have complex programs, the authority to approve changes in-house makes the program flexible and nimble. 

AUs and the RSO on a broad scope medical license must meet the same criteria for training and experience as for a limited scope medical license discussed above. 

Regulatory Services by Versant Physics


Our team of experienced Radiation Safety Officers can help you navigate the NRC regulations and determine which license type is appropriate for your facility. Contact sales@versantphysics.com to speak to a team member or learn more about our Regulatory services.

12 Apr 2018

Versant’s Residency Program Receives CAMPEP-Accreditation

We’re excited to share that Versant Medical Physics & Radiation Safety’s Residency Program is now CAMPEP-Accredited.

Under the guidance of Lee Myers, Program Director, Versant Medical Physics’ residency program will be working with affiliated clinical facilities, Anne Arundel Medical Center and Hahne Regional Cancer Center. Our intensive 2-year program offers residents an incredible opportunity to learn from our own team of experienced medical physicists, as well as the knowledgeable faculty at each clinic.

Today’s route to becoming a Board-Certified Medical Physicist is through the successful completion of a Medical Physics degree, or its equivalent, from a CAMPEP-approved university program, which is then followed by the successful completion of a CAMPEP-approved Medical Physics Residency program. Versant Medical Physics made the decision to support and sponsor our Residency in an effort to “do our part” in making sure graduating medical physics colleagues have more opportunities to become board-certified.

For more information regarding our residency program,
Please contact Lee Myers at lee.myers@versantphysics.com.

08 Mar 2018

Celebrating International Women’s Day 2018

Happy #IWD2018 to Versant’s Owner & Managing Director!

At Versant Physics, we are proud to be a part of a team under Marcie Ramsay’s leadership. We’d like to honor Marcie this International Women’s Day. Thank you from all of us.

International Women’s Day (March 8)

A global day celebrating the social, economic, cultural, and political achievements of women. The day also marks a call to action for accelerating gender parity. International Women’s Day (IWD) has occurred for well over a century, with the first March 8 IWD gathering supported by over a million people in Austria, Denmark, Germany, and Switzerland. Today, IWD belongs to all groups collectively everywhere. IWD is not country, group, or organization-specific. Make International Women’s Day your day, everyday.

Learn More.

01 Feb 2018

Heath Physics Society 51st Mid-Year Meeting

The Versant Physics team will be attending the HPS 51st Annual Mid-Year Meeting in Denver, CO from February 4-7th! Stop by and visit us at booth #219. We’ll be available to provide demos of our cloud-based radiation safety software, ODYSSEY, and to share more about Versant’s personnel dosimetry management, equipment commissioning, educational programs, and other services.

10 Jan 2017

Introducing Versant Physics’ New Residency Program

Residents Will Benefit From Greater Access to Expert Faculty

Our two-year program combines practical clinical training in therapy physics with a strong background in radiation safety. The program is designed for candidates with graduate degrees in medical physics or relevant physical sciences who are interested in careers in radiation therapy physics.

More Information.

Versant Physics logo

Forum Article "Radiopharmaceutical Extravasation: Pragmatic Radiation Protection" published ahead of print

An article written by Versant team members Dr. Darrell R. Fisher, Ph.D. and Misty Liverett, M.S., CNMT was recently published ahead of print in Health Physics. The article provides an unbiased, scientific assessment of pragmatic and reasonable health physics actions that should be taken in response to inadvertent extravasation events. Click the link below to view the article.

Permits

THE PERMISSION SYSTEM FOR INVENTORY TRACKING, MACHINE MANAGEMENT & EQUIPMENT CATALOG MODULES

Permit Profile

Each permit has a dedicated profile of information that includes authorized personnel, radioactive material, machines, and devices. Permit conditions, completed audits, and forms are also found on this profile.

Authorized Condition Database

Create and view authorized conditions included on permits. Previously created authorized conditions are listed with their code, category, and description.

Permit Enforcement

Information specified on a permit not only serves as a record of that permit, but also controls what can be added to other modules. The location, owner and type of radioactive materials, machines, and equipment can be enforced by permits.

Permit Audits

Perform permit audits, mail the results to relevant personnel, and track responses to non-compliances.