16 Del. Admin. Code § 4465-F-7.0

Current through Register Vol. 28, No. 7, January 1, 2025

Section 4465-F-7.0 - Dental Facilities

7.1 In addition to the applicable provisions of Part F, Section 3.0, the requirements of Part F, Section 7.0 apply to dental facilities using intraoral, panoramic, and cephalometric x-ray equipment. Dental facilities using cone beam computed tomography (CBCT) technology shall follow applicable provisions of Part F, subsection 11.8.

7.2 Quality Assurance. In addition to the general quality assurance provisions in Part F, Section 3.0, the following requirements apply to a dental facility:

7.2.1 If using film, maintain a light-tight darkroom, use proper safelighting and safeguards, and evaluate darkroom integrity and daylight loading systems for film fog every six months and after a change that may impact film fog.

7.2.2 If using a filmless system, maintain and operate PSP and DDR systems according to manufacturer specifications.

7.2.3 Registrant shall provide initial orientation to x-ray operators to include but not limited to: positioning of the x-ray tube, image processing, operator location during x-ray exposure, source to skin distance, radiation protection, appropriate radiographic protocol, and applicable regulatory requirements. Records of training shall be maintained for inspection by the Agency.

7.3 Warning Label.

7.3.1 On systems manufactured on or before June 10, 2006, the control panel containing the main power switch shall bear the warning statement or the warning statement in Part F, subsection 7.3.2, legible and accessible to view: "WARNING: This x-ray unit may be dangerous to patient and operator unless safe exposure factors, operating instructions are observed."

7.3.2 On systems manufactured after June 10, 2006, the control panel containing the main power switch shall bear the warning statement, legible and accessible to view: "WARNING: This x-ray unit may be dangerous to patient and operator unless safe exposure factors, operating instructions and maintenance schedules are observed."

7.4 Radiation Exposure Control. Means shall be provided to initiate the radiation exposure by a deliberate action on the part of the operator, such as the depression of a switch. Radiation exposure shall not be initiated without such an action.

7.5 Exposure Control Location and Operator Protection. Except for units designed to be hand-held, the exposure control shall allow the operator to be:

7.5.1 Behind a protective barrier at least 2 meters (6.5 feet) tall or

7.5.2 At least 2 meters (6.5 feet) from the tube housing assembly, outside the path of the useful x-ray beam, while making exposures.

7.6 Administrative Controls.

7.6.1 Patient and image receptor holding devices shall be used when the techniques permit.

7.6.2 Except for units designed to be hand-held, the tube housing and position indicating device (PID) shall not be hand-held during an exposure.

7.6.3 Dental fluoroscopy without image intensification shall not be used.

7.7 Hand-Held Intraoral Equipment. In addition to the standards in this chapter, the following applies specifically to hand-held devices:

7.7.1 The hand-held x-ray system shall be equipped with a backscatter shield of not less than 0.25 mm lead equivalent and 15.2 cm (6 inches) in diameter that is positioned as close as practicable to the distal end of the position indication device.

7.7.2 The facility shall maintain documentation that each operator has completed training as specified by the manufacturer, and approved by the Agency.

7.7.3 The facility shall adopt and follow protocols provided by the manufacturer, and approved by the agency, regarding the safe operation of the device.

7.7.4 When operating a hand-held intraoral dental radiographic unit, operators shall wear a 0.25 mm lead equivalent apron, unless otherwise authorized by the Agency or a certified health or qualified medical physicist.

7.7.5 If the operator has difficulty in holding the device stationary during the exposure, the operator shall use a stand to immobilize the device.

7.7.6 The registrant shall secure the hand-held device from unauthorized removal or use, and report any lost or stolen device to the Agency within 24 hours of discovery.

7.7.7 The registrant shall maintain a Usage Log listing every procedure performed on a patient, to include user name, date, time of use. Usage Log shall be available for inspection by the Agency.

7.8 Beam-on indicators. The x-ray control shall provide visual indication whenever x-rays are produced. In addition, a signal audible to the operator shall indicate that the exposure has terminated. (21CFR 1020.31(j))

7.9 Multiple Tubes. Where two or more radiographic tubes are controlled by one exposure switch, the tube which has been selected shall be clearly indicated prior to initiation of the exposure. Only the selected tube can be energized. This indication shall be both on the x-ray control panel and at or near the tube housing assembly which has been selected. (21CFR 1020.31(k))

7.10 Mechanical Support of Tube Head. The tube housing assembly supports shall be adjusted such that the tube housing assembly will remain stable during an exposure unless tube housing movement is a designed function of the x-ray system.

7.11 Battery charge indicator. On battery-powered generators, visual means shall be provided on the control panel to indicate whether the battery is in a state of charge adequate for proper operation. (21CFR 1020.30(o))

7.12 Locks. All position locking, holding, and centering devices on x-ray system components and systems shall function as intended.

7.13 Technique Indicators.

7.13.1 For x-ray equipment capable of displaying technique factors, the technique factors to be used during an exposure shall be indicated before the exposure begins. If automatic exposure controls are used, the technique factors which are set prior to the exposure shall be indicated. (21CFR 1020.31(a)(1))

7.13.2 The requirement of Part F, subsection 7.12.1 may be met by permanent markings on equipment having fixed technique factors. (21CFR 1020.31(a)(1))

7.14 Exposure Reproducibility. For any specific combination of selected technique factors, the estimated coefficient of variation of the air kerma shall be no greater than 0.05. (21CFR 1020.31(b)(1))

7.15 Timers. Means shall be provided to terminate the exposure at a preset time interval, a preset product of current and time, a preset number of pulses, or a preset radiation exposure to the image receptor. (21CFR 1020.31(a)(2))

7.16 Kilovolt Peak. Deviation of technique factors from indicated values shall not exceed the limits provided by the manufacturer. (variation of 21CFR 1020.31(a)(4)) At a minimum, the kVp on variable kVp units shall be accurate to within 10 percent and within 20 percent on fixed kVp units.

7.17 X-ray Beam Alignment.

7.17.1 The useful x-ray beam shall be limited to the area of clinical interest.

7.17.2 Intraoral Dental Units

7.17.2.1 X-ray systems designed for use with an intraoral image receptor shall be provided with means to limit the source-to-skin distance (SSD) to not less than18 cm (21CFR 1020.31(i)(1))

7.17.2.2 The x-ray field at the minimum SSD shall be containable in a circle having a diameter of no more than 7 cm. (21CFR 1020.31(f)(1)(i))

7.17.3 Extraoral, Panoramic and Cephalometric Units

7.17.3.1 X-ray systems designed for use with extraoral image receptors and when used with an extraoral image receptor, shall be provided with means to limit the x-ray field in the plane of the image receptor so that such field does not exceed each dimension of the image receptor by more than 2 percent of the SID, when the axis of the x-ray beam is perpendicular to the plane of the image receptor. In addition, means shall be provided to align the center of the x-ray field with the center of the image receptor to within 2 percent of the SID, or means shall be provided to both size and alignment the x-ray field such that the x-ray field at the plane of the image receptor does not extend beyond any edge of the image receptor. These requirements may be met with: (21CFR 1020.31(f)(4))

7.17.3.1.1 An assortment of removable, fixed-aperture, beam-limiting devices sufficient to meet the requirement for each combination of image receptor size and SID for which the unit is designed. Each such device shall have clear and permanent markings to indicate the image receptor size and SID for which it is designed; or (21CFR 1020.31(f)(4)(ii))

7.17.3.1.2 A beam-limiting device having multiple fixed apertures sufficient to meet the requirement for each combination of image receptor size and SID for which the unit is designed. Permanent, clearly legible markings shall indicate the image receptor size and SID for which each aperture is designed and shall indicate which aperture is in position for use. (21CFR 1020.31(f)(4)(iii))

7.18 Beam Quality. The Half Value Layer (HVL) of the useful beam for a given x-ray tube potential shall not be less than the values shown in Table 1. If it is necessary to determine such half-value layer at an x-ray tube potential which is not listed in Table 1 of this section, linear interpolation or extrapolation may be made. Positive means shall be provided to ensure that at least the minimum filtration needed to achieve beam quality requirements is in the useful beam during each exposure. In the case of a system, which is to be operated with more than one thickness of filtration, this requirement can be met by a filter interlocked with the kilovoltage selector which will prevent x-ray emissions if the minimum required filtration is not in place. (21 CFR 1020.30)

Table 1

(21CFR 1020.30(m))

Click here to view Image

7.19 Intraoral dental x-ray machines shall not be operated at less than a measured 51 kVp effective 2 years after the publication of this rule.

7.20 Modification of certified diagnostic x-ray components and systems.

7.20.1 Diagnostic x-ray components and systems certified in accordance with 21 CFR Part 1020 shall not be modified such that the component or system fails to comply with any applicable provision of this Part. (21CFR 1020.30(q) but doesn't mention variance option)

7.20.2 The owner of a diagnostic x-ray system who uses the system in a professional or commercial capacity may modify the system provided the modification does not result in the failure of the system or component to comply with the applicable requirements of this Part. The owner who causes such modification need not submit the reports required by this Part, provided the owner records the date and the details of the modification in the system records and maintains this information, and provided the modification of the x-ray system does not result in a failure to comply with this Part. (21CFR 1020.30(q)(2))

7.21 Leakage Radiation from the Diagnostic Source Assembly. The leakage radiation from the diagnostic source assembly measured at a distance of 1 meter in any direction from the source shall not exceed 0.88 milligray (mGy) air kerma (vice 100 milliroentgen (mR) exposure) in 1 hour when the x-ray tube is operated at its leakage technique factors. If the maximum rated peak tube potential of the tube housing assembly is greater than the maximum rated peak tube potential for the diagnostic source assembly, positive means shall be provided to limit the maximum x-ray tube potential to that of the diagnostic source assembly. Compliance shall be determined by measurements averaged over an area of 100 square centimeters with no linear dimension greater than 20 centimeters. (21CFR 1020.30(k))

7.22 Radiation from Components Other Than the Diagnostic Source Assembly. The radiation emitted by a component other than the diagnostic source assembly shall not exceed an air kerma of 18 microgray (vice 2 milliroentgens exposure) in 1 hour at 5 centimeters from any accessible surface of the component when it is operated in an assembled x-ray system under any conditions for which it was designed. Compliance shall be determined by measurements averaged over an area of 100 square centimeters with no linear dimension greater than 20 centimeters. (21CFR 1020.30(l))

7.23 Maintaining Compliance. Diagnostic x-ray systems and their associated components used on humans and certified pursuant to the Federal X-Ray Equipment Performance Standard ( 21 CFR Part 1020) shall be maintained in compliance with applicable requirements of that standard.

16 Del. Admin. Code § 4465-F-7.0

16 DE Reg. 1274( 6/1/2013)
22 DE Reg. 401( 11/1/2018) (Final)