5.6 - Ionizing Radiation

The Division Head of Oral Diagnosis and Radiology must have advanced training in radiation physics, radiation biology, radiation protection, radiographic techniques, and radiographic interpretation appropriate for the group being instructed.  All dental faculty and teaching staff that supervise student clinical radiology activities must have credentials signifying their qualifications and good standing within their disciplines.  Students must be supervised by the teaching staff and faculty during all radiographic procedures.

The College's ionizing radiation guidelines comply with the Radiation Control for Health and Safety Act authorized by FDA, the Consumer-Patient Radiation Health and Safety Act, the Oklahoma Department of Health Rules and Regulations, the Oklahoma State Dental Practice Act, and the recommendations of the American Dental Association and the American Academy of Oral and Maxillofacial Radiology.

The Division Head of Oral Diagnosis and Radiology shall serve as the College's Radiation Protection Representative (RPR) with advice and input from the Clinic Operations Committee. 

1. The RPR is responsible for establishing, implementing, and monitoring policies on radiographic practices for all diagnostic radiation sources in the College. They will also work in cooperation with established university radiation standards and radiation protection programs to coordinate, monitor, and control the use of x-ray and other imaging equipment.
2. RPR will work in cooperation with the Director of Compliance and the Health and Safety Committee at the College of Dentistry.
3. Only faculty, students, and staff certified by training will acquire radiographic images. Students will perform the radiographic procedures under the supervision of dental faculty and trained staff.
4. The dental faculty and the student will establish a need for diagnostic radiographic images by tentative diagnoses by evaluation of patient history and clinical examination. Faculty will prescribe the appropriate radiographic procedures in electronic health record system before exposure.
5. The RPR will conduct periodic continuing education programs for all staff operating x-ray generating and processing equipment. All such staff must be thoroughly conversant with all materials regarding radiation hazards, safety practices, and state and federal radiation rules and regulations.
6. Radiographic images made as part of a diagnostic workup should be confined to the Oral Radiology clinic whenever possible. Reasonable exceptions are radiographic images made as part of treatment in other clinics, off-site training programs, and student externships and unavailability of radiology clinic.
7. The RPR is responsible for implementing and monitoring a facility-wide radiographic quality assurance program. The RPR and the Clinic Policies Committee are responsible for controlling the use of ionizing radiation and for ensuring the consistent application of this policy by all clinical departments and programs. Every entity with radiographic capacities is expected to monitor daily compliance with this policy. All actions taken to maintain safety and quality must be documented with quality assurance activities in each department. Applicable portions of this policy must be posted or otherwise available in each satellite area.

Introduction: The appropriateness of dental care is intimately related to the accuracy of diagnosis. Dental radiographic images constitute a vital diagnostic tool in dental practice. While the risks of ionizing radiation to patients and operators are not fully understood, statistical risk estimations must be weighed against specific benefits. Risk analysis is usually based on the biological effects seen in laboratory studies and at higher doses. These data are then extrapolated, and inferences are made about the hazards to human beings exposed to x-radiation. It is accepted that diagnostic levels of x-radiation can potentially cause harmful effects. This concern alone demands that professional judgment always be used when handling radiation. 

Purpose: The purpose of this document is to establish guidelines that will govern the use of ionizing radiation within the College of Dentistry. The intent is for patients to receive minimal radiation necessary for diagnosis and treatment. The decision to expose any patient to radiation for diagnostic purposes should consider that any exposure to ionizing radiation is potentially harmful. The policy statements in this document apply to all patients treated or evaluated within the College of Dentistry. The only exceptions are consenting patients participating in research protocols approved by the Radiation Safety Committee and the Office of Research Administration / Institutional Review Board of the University of Oklahoma Health Sciences Center (OUHSC). 

The ionizing radiation guidelines in this section are reviewed annually and revised, as necessary. They incorporate those procedures and protocols that improve the risk-benefit ratio by maximizing the diagnostic yield from radiography and minimizing exposure to unnecessary radiation. Staff, faculty, and students are expected to be thoroughly familiar with these guidelines and to apply them in every instance of radiation use.

Policy Statement: To minimize radiation exposure to faculty, staff, students, and patients, the making of all radiographic images must be strictly governed according to the following protocols:

1. Follows the published Food and Drug Administration, American Dental Association, and the American Academy of Oral and Maxillofacial Radiology guidelines, standards, and regulations pertaining to use of dental radiation and prescribing dental radiographs.
2. The prescription for all radiographic images must be added to the patient's record and authorized by the licensed attending dental faculty member. Prior radiographic images, if available, should be evaluated before new radiographic images are ordered. Only those additional views needed for complete diagnosis/treatment planning will be exposed. This does not preclude making a new intraoral full mouth survey if it is appropriate to the diagnosis.
3. The need for all radiographic images, as established through history and clinical examination, is based on the professional judgment of dental faculty and licensed dentists.
4. Radiographic images ordered on a routine basis, without patient’s need, are prohibited. Screening radiographic images will be kept to the number needed to determine the acceptance of a patient for treatment and will become part of any subsequent diagnostic radiograph series in the patient’s record.
5. When a need for radiographic images is established, students will be required to produce a minimum number of radiographic images consistent with an adequate diagnosis of disease.
6. Radiographic images should only be made on patients capable of compliance. Non-compliant patients may be referred for the procedure to be done under appropriate sedation.
7. The need for radiographic images during and/or after treatment, and the frequency of recall radiographs, will be based on the patient's needs and the professional judgment of the attending dental faculty.
8. Retakes/remakes should be approved by a faculty supervisor or radiology staff before retaking any images. The student must identify the faulty image, cause of error and correction method. Faculty or trained staff must provide input and assist students during retakes. Students may retake an image once after consulting with faculty or trained staff. If additional retakes/remakes are needed, they must be done under the direct supervision of the faculty or trained staff. Retakes should be taken only for a valid clinical or diagnostic reason, not the purpose of improving the esthetics of the radiograph.
9. If a student is judged to lack the required technical skills, they will be required to complete a competency review in technique and knowledge of radiation protection principles with the Division Head of Oral Radiology.
10. Radiographic surveys shall show appropriate region of interest including crown of teeth, root apex, surrounding periapical bone, and each crown with minimum overlapping.
11. The policy for exposing radiographic images for staff, faculty, students and patients is the same.  Radiographic exposures will only be made when there is a potential benefit by the discovery of useful information on the radiograph.
12. Radiographs for teaching purposes only are not allowed. 
13. Radiographic images will not be made only for administrative or research purposes (including insurance claims or legal proceedings). However, diagnostic radiographic images may be used for administrative purposes. Radiographic images of patients will also not be made only for training or demonstration.
14. Professional judgment and selection criteria must be used to determine the frequency and extent of each radiographic exposure.  Every effort must be made to limit radiation exposure to the patient and the operator.  
15. Imaging For Research: Any research related radiographic imaging activity must be approved prior to start of a project by the Institutional Review Board (IRB) at the University of Oklahoma Health Sciences Center. Activity must stop at the end of approval period from IRB.
16.  ALARA principle applies to all types of imaging. All the radiographs must be prescribed by a licensed faculty member.  Appropriate codes should be entered and completed in the patient’s electronic health record.

All exposed radiographic images must be made according to the following guidelines. Any technical deviations must be approved by the attending dental faculty or trained staff. 

1. A clinical examination must be performed first to determine if radiographs are needed or not. Based on clinical judgment and the patient’s history, the provider decides what radiographs (type and number) are needed.
2. Providers must ask the patient if any radiographs were taken outside OUCOD. If yes, ask the patient to provide any details they can remember such as the date taken, what type, and how many. 
3. For pre-doc clinics, radiographs from outside practices can be emailed to radiology at CODRADIOLOGY@OUHSC.EDU.
4. Patients can request an outside practice to email the radiographs to OUCOD on this email. Radiology staff cannot make this request. Radiology staff can only upload images that are digitally received on this email. It would be best if radiographs were received before the day of the appointment.
5. If any radiographs are found to be undiagnostic, retakes can be done based on the clinical judgment of the provider/faculty.
6. To minimize risks associated with radiation exposure, use the fastest imaging system appropriate for the diagnostic need. At OUCOD, digital image receptors of varied sizes are used. 
7. Periapical and bitewing radiographic images are acquired with circular or rectangular collimation that limits the beam to a diameter of 2.75 inches or less at the patient's face. Use open-ended, shielded beam-indicating devices (BID) only. 
8. Ensure that the target-to-skin distance for intraoral radiography is no less than 8 inches. Long BID length is preferred. 
9. Use image receptor holding devices during standard intraoral techniques. Digital retention of intraoral image receptors is not recommended. 
10. Protective body aprons and thyroid shields are currently optional for all intraoral radiographic imaging.
11. Operators using hand-held devices must wear protective aprons.
12. Operators should not hold patients or image receptors during the radiograph exposures. If assistance is required for children or disabled patients, an adult member of the patient's family or other non-radiation staff may help. If the need arises, the operator must wear a protective apron when stabilizing the patient or image receptor and stay out of the primary X-ray beam. 
13. The operator should not stabilize or hold the tube head of a wall-mounted or mobile x-ray unit on wheels by hand during exposures. During each exposure, the operator should stand out of the primary beam and stand behind an adequate protective barrier that permits patient observation and communication. The tube head must not vibrate or drift during exposure. 
14. For fixed wall-mounted tube heads, the exposure button must be located behind the barrier or at a safe distance. Operators must apply continuous pressure on the exposure button throughout the exposure time until the exposure cycle has been completed. 
15. Portable mobile X-ray generators and hand-held devices such as Nomad must be used with proper precautions.
16. Fixed wall-mounted X-ray generators shall have a posted list of “average” exposure factors that are appropriate for the views taken with that machine. Professional judgment must be used if an adjustment is needed.
17. All x-ray generators must meet federal requirements for collimation and filtration: Total filtration of x-ray machines should not be less than 1.5 mm aluminum equivalent at 70 kVp or less and not less than 2.5 mm on machines operating above 70 kVp.  Collimation: beam diameter of 2.75 inches or less at the patient's face.
18. If a malfunction is detected in an x-ray generating unit, do not use the unit unless the necessary corrections have been made and the equipment recalibrated. Report the malfunction to the Division Head of Oral Diagnosis and Radiology. 
19. For extraoral radiography, restrict radiographic images to the area in question and with the beam collimated equal to or smaller than the size of the image receptor. Use the fastest extraoral digital image receptors appropriate for the diagnostic need.
20. The number of radiographs needed for a patient will vary depending on the type of encounter, various clinical situations, history, risk factors, available radiographs, etc. Please review the ADA/FDA guidelines for prescribing dental radiographs.  
21. There is no such practice as taking radiograph(s) every 6 months or every year on a patient. This is incorrect practice. Taking radiographs before any clinical examination is also an incorrect practice.
22. All radiation exposures for each patient must be included in the patient's record.
23. Current ADA / FDA guidelines for prescribing dental radiographs can found at: https://www.fda.gov/radiation-emitting-products/medical-x-ray-imaging/selection-patients-dental-radiographic-examinations
24. Evidence for discontinuing radiographic shielding: https://jada.ada.org/article/S0002-8177(23)00391-4/fulltext
    As you will note, the Position Statement makes two recommendations:
    1. Discontinuing shielding of the gonads, pelvic structures, and fetuses during all dentomaxillofacial radiographic imaging procedures
    2. Thyroid shielding not be used during intraoral, panoramic, cephalometric, and cone-beam computed tomographic imaging

The College of Dentistry will follow standard/universal precautions during all patient care. The operator is required to adhere to the following infection control practices before, during, and after all radiographic exposures:

RADIOLOGY ROOM SET-UP AND INFECTION CONTROL PROCEDURES

***NOTE TO Student: Please read before you start.

Before retrieving your patient:

• Your room will be assigned by one of the staff in Radiology.
• Each room will only have a Dexis sensor on the wall holders next to the monitor.
• All other clean supplies will be on the table inside the room except cotton rolls, edge ease, tube cover, and rubber bands.
• Be sure to wash (sanitize) your hands before setting up your room.
• Chair: Place a clean big (opaque colored) plastic bag on the chair's back.
• BID: Secure a plastic bag on the tube head.
• Place a rubber band on the BID to keep the plastic bag tight.
• Put blue sticky barrier tape on three (3) items: the timer button inside the room, the mouse, and the exposure button outside the room.
• Place a blue napkin on one side of the keyboard tray, inside the room. This is for your sensor and XCP’s as you use them in the patient’s mouth. Since the items will become contaminated, this napkin will keep them isolated in one place.
• Cover the keyboard with a plastic bag in the room called a “Keyboard Cover”.
• Cover the sensors with a plastic sleeve first, then place a finger cot over the plastic sleeve. Lay the covered sensor on top of the blue napkin.

***Put on your gown, mask, and protective eyewear: DO NOT WEAR GLOVES TO GET THE PATIENT. Your gloves will be placed when starting images.

Bringing the patient back to the room:

• At the patient's request, place the protective shielding on the patient.
• Remove the patient’s eyeglasses and any removable dentures.
• Discuss exposure time with the assigned staff member before taking images.
• Be sure to wash your hands, put on clean gloves, then start your images.
• When you have completed your images, they will be evaluated and approved before you dismiss the patient and begin room clean-up.
• Once approved, remove your gloves, then take off the lead apron and collar from the patient, hang them up, and dismiss the patient to the waiting room, escorting them if necessary.

ROOM CLEAN-UP PROCEDURES

After dismissing the patient:

• Put on a new pair of gloves.
• Remove all barriers placed: chair, tube head, timer button, mouse, exposure button, tray, and sensor.
• Take all contaminated instruments (XCPs, etc.) and borrowed eyewear to the sterilization room marked “Darkroom”.
• Disassemble the instruments, then place the items in the container of soapy water specifically marked for each item.
• Return to the room used for images, put on a new pair of gloves, and begin clean-up with “PDI Wipes”.
• Disinfect the chair and the tube head arms, not the tube head.
• Remove barriers from the sensor, wipe the cord, and then hang it up in the slot provided on the wall. If a breach (saliva contamination) occurs during images, wipe the sensor with PDI wipes (gently and not over-saturated) before hanging the sensor in the slot provided on the wall.
• Disinfect the black tray that holds the keyboard and mouse.
• Disinfect the protective shielding, if used.
• Remove your gown; however, remain in your mask until exiting the clinic.

1.  While wearing clean gloves, place a transparent plastic sleeve over the sensor using the outer sleeve to cover the activation switch.

2. Next, slide the finger cot (nitrile barrier) over the transparent sleeve and sensor.

3. Take the images with XCP and the sensor.

4. Remove contaminated gloves. While wearing clean gloves, remove all barriers from the sensor.

5. Disinfect the cord only with PDI wipes.

6. DO NOT DISINFECT THE SENSOR. Only if a breach has occurred (saliva contamination), disinfect the sensor with a PDI wipe. 
7. Hang the sensor on the wall or place it into the sensor case.

Portable or mobile X-ray equipment is defined as an X-ray machine mounted on a permanent base with wheels and/or casters for moving while completely assembled. Below are additional requirements for portable X-ray equipment (in addition to the requirements for wall-mounted X-ray units):

1. Before using a new machine, approval from the Division Head Oral Diagnosis and Radiology will be obtained for a specific location(s) and procedures to ensure compliance with x-ray permits. The machine will be tested by the Radiology staff before use.
2. During the exposure, the operator: 
   a. Must be positioned so that their exposure is as low as reasonably achievable (ALARA). 
   b. Should never be in line with the direct/primary x-ray beam. 
3. Operators and bystanders (other than the patient) should be at least 6 feet away from the x-ray machine when energized or have suitable shielding utilized.
4. The tube housing should not be held by the operator during exposure.
5. Infection control guidelines must be followed.

NOMAD is a Food and Drug Administration (FDA) 510(k) approved hand-held x-ray unit that has demonstrated substantial equivalence to a portable intraoral x-ray system designed for field use. The patients scheduled for routine intraoral radiographs at the College of Dentistry will continue to be imaged using fixed wall-mounted or mobile X-ray machines. The radiology division will provide training for the safe use of NOMAD to the staff, faculty, and students. Dental and hygiene students will be introduced to the fundamentals of using the NOMAD X-ray device during the pre-clinical radiology courses. Training sessions will be offered periodically for the staff and faculty. Daily, attending clinical faculty or the clinic dispensary staff should be familiar with safe handling of the hand-held. Help and training should be sought from Radiology as needed. 

Below is a summary of guidelines for NOMAD (hand-held X-ray generator):

1. The NOMAD must be checked out by the operator from the clinic dispensary or staff office.
2. Students using the NOMAD will be under the supervision of the attending faculty. Standard radiation protection procedures must be followed; the only exception is that the operator of the NOMAD is physically present in the operatory with the patient during the x-ray procedure.
3. The NOMAD’s circular protective shield must always be in place, at the recommended position (on the outer edge of BID towards the patient).
4. Operator must try to stay behind the Nomad during exposure and try to hold it as close to the patient’s face / target as possible.
5. Image receptor holding devices (XCP or tabs) should be used with the Nomad.
6. Shorter XCP rods are available in clinics for using with NOMAD.
7. Operator must use both hands to hold the Nomad unit to ensure steady support during the procedure.
8. Nomad must be returned to dispensary personnel upon completion of the x-ray procedures.
9. According to the recommendation by the medical physicist, the operator must use a protective body apron during the imaging.
10. Operator must make sure that the Nomad and the patient will not move during the procedure.
11.  Operators must keep all others at least 6 feet away from the primary source of radiation.
12. Nomad can only be used in approved locations. For example, general waiting areas are not approved locations.
13. To prevent the spread of infections, the Nomad should be disinfected after every patient using wipe-discard-wipe technique with approved wipes.
14. Persons (students, staff, and faculty) using the Nomad machine will be responsible for controlling the immediate area in which the device is used.
15. In situations such as research studies, where one operator may be taking extreme numbers of images, a radiation-monitoring device may be required.

The staff in the main radiology clinic will be responsible for the quality control checks in the clinics and implementing whatever corrective measures are necessary to maintain the quality of the radiographic images.

1. All machines capable of producing ionizing radiation and processing units are under the auspices of the Division Head Oral Diagnosis and Radiology. An annual inspection of all X-ray equipment will be done to maintain performance standards by a qualified radiation physicist. Inspection reports will be kept in a logbook in radiology.
2. Any irregularity or malfunction in an X-ray generator will necessitate that it be turned off until a determination has been made, by a qualified radiation expert, that it is safe to operate. 
3. An X-ray generator should not be operated by any student or staff in such a fashion that it would endanger either the operator or the patient. Failure to observe this will result in the discontinuation of radiology privileges.

All radiation workers should receive as little radiation as reasonably achievable (ALARA). Personal radiation monitoring devices (Thermoluminescent personnel monitoring devices) or dosimeters can be worn during working hours by all faculty and staff who regularly use the X-ray equipment. Request to wear a badge must be made via email to the Division Head Oral Diagnosis and Radiology.

Radiation workers: No employee (radiation worker/occupationally exposed worker) should receive more than 5 rems (5,000 mrem or 0.05 sievert) whole-body radiation exposure each year. This is the radiation protection guide value. For an added precaution, quarterly readings above 10 percent of the radiation protection guide (0.5 mSv, or 50 mrem) should be investigated. Dosimetry reports must be kept as a permanent record for each employee and be made available for inspection by the employee.

Declared pregnant radiation worker: The worker's dose limit remains at 5000 mrem per year regardless of her declaration of pregnancy. The Declaration of Pregnancy initiates the dose limit for the fetus. The dose limit for the fetus is 500 mrem for the entire pregnancy. If, upon declaration of her pregnancy, the fetal dose is determined to already be 450 mrem or more, the worker's dose limit for the remainder of her pregnancy is 50 rem.

The Radiation Safety Officer (RSO) of the University of Oklahoma College of Dentistry must receive written notification of pregnancy from the pregnant individual. It is recommended that a pregnant radiation worker declare her pregnancy so that her occupational radiation exposure potential can be evaluated to ensure that the dose to the unborn child does not exceed 500 mrem (0.5 rem) over the duration of the pregnancy. Please consult with RSO and / or Division Head of Oral Diagnosis and Radiology for further assistance.

Radiation safety manual of the University of Oklahoma Health Sciences Center can be found at:

Radiation Safety Office Documents (ouhsc.edu)

General public: The limit to members of the public (including employees not involved in working with sources of ionizing radiation) is 100 mrem (1 mSv) per year resulting from licensed or registered activities at this institution.

All radiation exposures for each patient must be included in the patient's record.

This form letter is provided for convenience. To make a written declaration of pregnancy, fill in the blanks in this form letter, use a form letter the licensee has provided, or compose your own letter. Submit this to the Director of Compliance at OUCOD.

DECLARATION OF PREGNANCY 

To: ________________________________________________ 

            In accordance with the NRC’s regulations at 10 CFR 20.1208, “Dose to an Embryo/Fetus,” I am declaring that I am pregnant. I became pregnant in ____________________ (only the month and year need to be provided). 

            I understand the radiation dose to my embryo/fetus during my entire pregnancy will not be allowed to exceed 0.5 rem (5 millisieverts) (unless that dose has already been exceeded between the time of conception and submitting this letter). I also understand that meeting the lower dose limit may require a change in job or job responsibilities during my pregnancy. 

________________________________ 

(Your signature)

________________________________ 

(Your name printed) 

________________________________ 

(Date) 

8.13-8.13-11

Please contact Director of Compliance at the University of Oklahoma College of Dentistry for further guidance.

Further information about radiation safety can be found at the main office of University of Oklahoma Health Sciences Center, Office of Compliance:  http://compliance.ouhsc.edu.