Introduction

In keeping with the goals of the Department of Dental Hygiene to prepare students to provide high quality care for all patients, these guidelines regarding exposure of radiographs have been established. The guidelines have been developed to assist you in making decisions with instructor approval, before exposing radiographs. Since dental radiography presents the risk of long term sequelae that may result from radiation of the oral cavity, it is vital that the patient's relative risk benefit ratio be assessed. The quality of oral health care must be maintained at a high level while minimizing the potentially deleterious effects of radiation exposure to the patient as well as the operator. It is our responsibility to use professional judgment in applying the guidelines in assessing any patient's need for radiographs.

Policy

1. All radiographs shall be approved by a faculty member at the time of the medical history review and clinical screening examination.
2. Evaluate prior radiographs before new radiographs are made. Expose additional radiographs as needed.
3. The patient must be capable of cooperating.
4. Patients must be given the reasons why radiographs are being taken, and the patient must give his/her informed consent in writing prior to exposure. Minors must have a parent or guardian approval.
5. The need for radiographs during treatment and post-operatively and the frequency of recall radiographs shall be based on the patient's need and approval by the instructor.
6. Radiographs for third parties (insurance) shall not be made.
7. Students must meet competency on radiographs exposed on DEXTRs. as determined by criteria established in the radiology laboratories before exposing patients.
8. Radiographs shall not be made on patients for the purpose of training or demonstration. If a patient needs radiographs for diagnostic purposed they may participate in educational activities. These radiographs may not be taken by a student, however, until that student has successfully completed the radiology laboratory class.
9. No retakes are permitted without the instructor's permission. The instructor shall supervise retakes. A complete intraoral radiographic survey shall demonstrate each root apex and periapical bone and each crown with minimum overlapping.
10. Vertical bitewing surveys are recommended for periodontally involved patients, in place of horizontal bitewings.
11. Radiographs may be taken upon written prescription from the patient's dentist.
12. Radiographs may be purchased by the patient for use by their dentist. Upon completion of the Radiographic Request Form the radiographs will be mailed to the appropriate dentist. Radiographs may be picked up by the patient, if the student makes arrangements to meet the patient to deliver them.
13. Radiographic exposure requirements and grading criteria will be established on a semester basis as student skills improve.
14. A lead apron and thyroid collar is used on all patients making sure the lead collar does not obstruct the rays on a panoramic survey. Hang the apron and collar on rack provided when not in use.
15. A consultation with the patient's physician is required before radiographs are taken of patients who have had recent extensive medical or therapeutic exposure to radiation.
16. A panoramic radiograph with bitewings and selected Periapicals are interchangeable with a FMX.
17. Aseptic technique will follow the established clinical protocol.

NOTE: These guidelines are based on a clinical teaching situation and do not necessarily reflect all private practice protocol.

Selecting the Patient

These guidelines were established by the US Department of Health and Human Services

New Patient: All new patients may receive x-rays to assess dental disease and growth and development.

• Child: Posterior BWX if the interproximal spaces aren't visible clinically. Panoramic radiograph to look at growth and development of the permanent dentition. May also take PA's/occlusal views with posterior with BWX..
• Adolescent: Individual BWX and selected PA's. A FMX is appropriate when the patient presents with generalized dental disease or a history or extensive previous dental work.
• Adult: Same as for an adolescent.
• Edentulous: FMX or preferable a panoramic radiograph.

Recall Patient: Clinical caries or high risk factors for caries.

• Child: Posterior BWX at 6 mo intervals or until no caries is evident.
• Adolescent: Posterior BWX at 6 to 12 mo intervals or until no caries is evident.
• Adult: Posterior BWX at 12 to 18 mo intervals.
• Edentulous: N/A

Recall Patient: No clinical caries and no high risk factors.

• Child: Posterior BWX at 12 to 14 mo intervals if interproximals aren't visible clinically. For transitional dentition, 12 to 24 mo intervals.
• Adolescent: Posterior BWX at 18 to 36 mo intervals.
• Adult: Posterior BWX at 24 to 36 mo intervals.
• Edentulous: N/A

Recall Patient: Perio disease or a history of perio tx.

• Child: Selected PA's as needed
• Adolescent: Selected PA's and BWX as indicated clinically
• Adult: Selected PA's and BWX as indicated clinically
• Edentulous: N/A

Recall Patient: Growth and development assessment.

• Child: not indicated, except for transitional dentition, and then use occlusal and /or pan.
• Adolescent: PA's or pan for third molars
• Adult: N/A
• Edentulous: N/A

Infection Control In Dental Radiography

Introduction

• The exposure of dental radiographs does not carry the same risks for needle and instrument sticks, exposure to aerosols, and risk of the transmission of infectious disease that is present for most dental procedures. There remains, however, a high risk of cross-contamination between radiographic patients while exposing and processing radiographs. It is therefore necessary to follow accepted aseptic guidelines while exposing and processing radiographs.

Sources of Contamination

• Unexposed and exposed film
• Dental chair
• Tube head, PID, and arms
• Control panel and dead-man switch
• Lead apron and thyroid collar
• Panoramic positioning devices
• Operatory door handles
• Film holders
• Developing tanks
• Film positioning devices

Barrier Protection

1. Gloves: Non-sterile latex or vinyl gloves for intraoral procedures and processing. Utility gloves for operatory clean-up and handling contaminated instruments.
2. Masks: Protect the mouth and nose from potentially infectious aerosol particles and mucous membranes from direct contamination. Masks should be changed for every patient.
3. Protective Eyeglasses: Contaminated glasses should be thoroughly washed with soap and water, rinsed and disinfected.
4. Clothing: Laboratory coat.
5. Surface covers: Tube head and PID wrapped in plastic bag. Plastic wrap on control panel, dead-man switch, door handles, and chair controls.

Infection Control Protocol

1. Surface cleaning and disinfecting: Student clinicians are responsible for all infection control procedures in the operatories. Barrier techniques are used wherever possible. Surfaces touched and not protected by barriers must be cleaned and disinfected between patients. This includes:
   • tube head, PID, and arms
   • chair, headrest, armrest, back k support, and chair controls
   • control panel and dead-man switch
   • light switches and doorknobs
   • any surfaces where exposed film or contaminated instruments are place
2. Instrument sterilization
   • Snap-o-ray and Rinn instruments must be properly washed, bagged, and sterilized after each use. (This is the responsibility of the clinician, not the x-ray assistant.)
3. Patient Screening
   • Clinicians must follow universal precautions.
   • The patient's medical history must be evaluated for indications of infectious disease.
4. Utilization of lead apron and thyroid collar.
   • Placement: lead apron and thyroid collar should be placed prior to gloving to prevent contamination.
   • Removal: lead apron and thyroid collar should be removed following removal of gloves and hand washing.
5. Handling of Film
   • The x-ray assistant who dispenses film must wash hands prior to dispensing film.
   • Film are places on a tray set-up for distribution to the clinician. The tray should be covered until used.
   • Exposed film are placed in a paper cup for r transport to the darkroom. The developing assistant opens the film packet with gloved hands and drops the exposed film onto a clean, dry paper towel. When all film are opened, the assistant removes the gloves and wipes hands with an alcohol towelette to remove the powder. The exposed film are then run through the developing process.
6. Exposing radiographs
   • Lab coats are removed in the clinician's cubicle prior to entering the x-ray operatory.
   • Clinician must wear masks, protective eyewear, and gloves. (Masks and eyewear from the cubicle may be used: the student must perform a new hand washing according to acceptable clinical standards and don a fresh pair of gloves prior to taking x-rays.)
   • Upon completion of x-rays procedures, the clinician will remove gloves, wash hands, remove mask, and return to the clinical operatory.
   • Students are to take their own contaminated instruments back to their cubicle, in a clean paper towel, for cleaning and sterilization.

Exposure Procedures

1. Use only E speed film.
2. Circular collimation is limited to a beam diameter of 2.75 inches or less at the patients face. Only lead-lined, open ended PIDs shall be used.
3. The target to skin distance shall not be less than 7".
4. Film holding devices shall be used rather than digital retention of film. Paralleling technique is to be used unless the patient cannot cooperate.
5. Lead aprons and thyroid collar must be used on all patients. Use the double sided shield for panoramic.
6. Any malfunctioning unit shall be corrected immediately and not used until servicing is complete.
7. Do not allow the tubehead to vibrate or drift during the exposure, and do not stabilize by hand during exposure.
8. No operator shall hold a patient or film during an exposure. A non-radiation worker or a patient's family member may help. The individual shall wear a lead apron and stay out of the primary beam.
9. The operator shall stand at least six feet away from the x-ray source and behind the appropriate barrier.
10. The exposure control switch shall be immobilized behind the barrier and requires the operator to have continuous pressure throughout the exposure.
11. Extraoral radiographs require the use of the portable lead shield, and the patient should be viewed during the entire exposure.

Performance Criteria for Periapical and Bitewing Exposures

Periapical Examinations:

1. General Considerations: All periapicals should demonstrate
   • 2-3 of alveolar bone visible beyond the apex of the tooth
   • Films should have adequate density and contrast for proper interpretation
2. Film Positioning for Periapical Exposures
   • Maxillary Central Incisor: The film packet is positioned so that the interproximal space between the two centrals is centered. The film must include both central incisors with open contacts between the central/central and central/lateral, and may include the following: incisive foramen, nasal fossa, mid-palatine suture, nasal septum, nasal conchae, ant. nasal spine, and soft tissue shadows.
   • Maxillary Lateral Incisor: The film packet is positioned so that the lateral incisor is centered. The film must include the lateral incisor with open contacts between the lateral/central and lateral/canine. The same structures as the central exposure may be present.
   • Maxillary Canine: The film packet is positioned so that the distal contact between the canine an premolar is centered. The film must include the canine with open contacts between the lateral/canine. (The interproximal space between the canine and premolar will be overlapped because of the film and PID placement.) Structures which may be evident are: fossa, sinus, inverted Y, and soft tissue shadows.
   • Maxillary Premolar: The film packet is positioned so that the distal of the canine is present, as well as the entire first and second premolar. The interpoximal contacts between the 1st premolar/2nd premolar must be open as well as the contacts between the 2nd premolar/1st molar. Structures which may be evident are: maxillary sinus, floor of sinus, malar, nasal fossa, floor of the fossa, and nasolabial fold.
   • Maxillary Molar: The film packet is positioned so that the second molar is centered on the film and all three molars are evident. Interproximal contacts are open between all molars. Structures which may be evident are: malar, maxillary sinus, hamulus, maxillary tuberosity, coronoid process, zygomatic arch, nasal fossa, and the floor of the nasal fossa and sinus.
   • Mandibular Incisors: The film packet is positioned so that the central incisors are centered on the film. Both central and lateral incisors must be present, with open interproximal spaces. Structures which may be evident are: lingual foramen, genial tubercles, inferior border of the mandible, mental ridge, tori, and soft tissue shadows.
   • Mandibular Canine: The film packet is positioned so that the distal contact between the canine and premolar is centered on the film. The entire canine must be present, with open contacts between canine/lateral, and canine/first premolar. Structures which may be evident are: the same as the mandibular incisor view as well as the mental foramen.
   • Mandibular Premolar: The film packet is positioned so that both premolars and the distal of the canine are present with all interproximal spaces open. Structures which may be present are: mental foramen, sub-mandibular gland fossa, inferior border of the mandible, mandibular canal, and tori.
   • Mandibular Molar: The film packet is positioned so that the second molar is centered on t he film and all three molars are evident. Interproximal contacts are open between all molars. Structures which may be evident are: mandibular canal, inferior border of the mandible, external oblique, internal oblique, and submandibular gland fossa.

Bitewing Examinations:

1. General Considerations: All bitewings should demonstrate:
   • Occlusal plane should be in the center of the film so that 2-3 mm of maxillary mandibular bone level is evident.
   • Films should have adequate density and contrast for proper interpretation.
2. Film Positioning for Bitewing Exposures:
   • Premolar: The film packet is positioned so that both premolars are present as well as the distal 1/3 of the canine and the mesial of the first molar. Interproximal spaces are open between canine/1st premolar, first premolar/2nd premolar, and 2nd premolar/1st molar.
   • Molar: The film packet is positioned so that the three molars are evident, with the 2nd molar centered on the film. Interproximal spaces are open between 1st and 2nd molar and 2nd and 3rd molar. (Note: Because of the difference in tooth morphology between maxillary and mandibular molars and in arch form, it may be difficult to open both maxillary and mandibular molars contacts simultaneously. In these instances, it is best to concentrate on opening the maxillary contacts.)
   • Posterior Vertical Bitewings: Vertical bitewing positioning is the same as that for premolar and molar film, with emphasis on adequate bone level being evident for interpretation of bone loss

Grading Criteria for FMX and BWX

1. FMX
   • -1 cone cutting
   • -1 horizontal angulation error
   • -1 vertical angulation error
   • -1 film packet placement error
   • -1 inadequate bone level
   • -1 exposed backwards
   • -1 movement
   • -5 Any error resulting in a diagnostically unacceptable radiograph which require a retake. (If the structures are not evident in another film.)
2. BWX
   • -2 cone cutting
   • -2 film packet placement error
   • -2 inadequate bone level
   • -2 horizontal angulation error
   • -2 vertical angulation error
   • -2 exposed backwards
   • -10 Any error resulting in a diagnostically unacceptable radiograph which requires a retake. Note: Students may receive extra points (up to 5 points) for management of a particularly difficult patient at the discretion of the instructor. Improper infection control will result in -10 points

Physical Facilities and Equipment

1. All radiographic equipment and facilities are evaluated by the State Division of Radiological Health at regular intervals.
2. Radiographic viewing is accomplished by use of a viewbox and opaque film mounts.
3. Lead aprons and thyroid collars are kept on hangers when not in use.

Records

1. Documentation of all radiation exposures for each patient shall be maintained in the patient's record. The record must include the number, type of radiographs, date of exposure, name of operator, name of faculty, and the patient's signed informed consent.
2. All radiographs shall be mounted in the appropriate mount and labeled with the patient's name, student's name, and date. Do not store loose, unmounted radiographs in the patient's file.
3. A formal interpretation of the radiographs is to be turned in with each radiographs, except for BWX and individual PAs.

Darkroom Quality Control

1. Automatic Developer Solution will be replenished and replaced by Ms. Shorter according to accepted guidelines of the manufacturer.
2. The automatic processor is to be maintained an cleaned on a weekly basis by Ms. Shorter.
3. The darkroom is to be cleaned by the students on a daily clinical basis. All cabinet tops, tanks, lids, cassettes, and hangers used, must be clean. The cabinet tops must be neat an orderly to eliminate the possibility of contamination or misplacing of film.
4. The darkroom door must remain locked during development to prevent the possibility of exposing film to white light.
5. The developing clinician is responsible for the maintenance of the darkroom during clinic. The clinician responsible for mounting x-rays must put the appropriate information on the mount and return the film to the clinician.
6. All film is stored in Ms. Shorter's office and film must be obtained from her for clinic use. Film in the radiology area are kept in the common area drawers.

Radiation Hygiene Guidelines

Failure to follow proper radiation safety will result in an automatic 10 point deduction from your total FMX or BWX grade. The Department of Dental Hygiene wants to maintain a safe environment, and these guidelines will help to prevent any unnecessary radiation exposure to you, your fellow students, and your patients. This includes the following:

1. no lead apron on the patient.
2. no thyroid collar on patient.
3. not closing the door completely or not stepping behind the lead barriers prior to exposure
4. not observing the patient through the lead glass during exposure
5. not setting the impulse and kvp prior to placing the radiograph in the patients mouth
6. leaving unexposed or exposed radiographic film in the x-ray room during exposure
7. exposing radiographs without the permission of an instructor
8. not filling out the x-ray log before exposing radiographs
9. leaving exposed radiographs without any identification or without informing the x-ray assistant, which then may be mislabeled or lost and thus require further patient exposure.
10. not recording the patient exposure on the chart

Manual Development Process

1. Lock darkroom door.
2. Record patient's name on hanger
3. Stir the solutions (always clean paddle before stirring fixer)
4. Check temperature of solution with thermometer and determine developing time
5. Turn on appropriate safelight and turn off overhead light
6. Open film packets with latex gloves and drop film onto a clean, dry paper towel.
7. Remove gloves, wipe hands with a handiwipe to remove powder.
8. Pick film up by edges and place on a dry rack.
9. Immerse film hanger in developer and time. (*Remember to agitate the film several times to remove any air bubbles.) Cover the developer.
10. Remove cover, rinse for 30 seconds to stop developer action. Agitate during entire 30 seconds.
11. Place in fixer for 10 minutes to completely fix. Film can be removed and overhead light may be safely turned on after 3 minutes in the fixer for a wet reading.
12. Place film in water bath for 20 minutes.
13. Dry film an demount in appropriate holder.
14. Take 10 minutes to rest from the ordeal of developing film. Pat yourself on the back for doing such a good job.

Automatic Processor

1. Lock darkroom door.
2. Record patient's name on film mount.
3. Make certain that the developer temperature is up to 81 degrees and that replenishing bottles are not empty.
4. Turn on appropriate safe light, and turn off overhead light.
5. Open film packets with latex gloves and drop film onto a clean, dry paper towel.
6. Remove gloves, wipe hands with a handiwipe to remove powder.
7. Pick film up by edges and place in the automatic processor. Never place more than one patient's x-rays in the processor at one time.
8. Mount x-rays in appropriate holder and return to operator.