HAR §11-45-120. Intraoral dental radiographic systems

(a) X-ray systems designed for use with an intraoral image receptor shall be provided with means to limit source-to-skin distance to not less than eighteen centimeters. (b) Radiographic systems designed for use with an intraoral image receptor shall be provided with means to limit the x-ray field such that the x-ray field at the minimum source-to- skin distance shall be containable in a circle having a diameter of no more than seven centimeters. (c) Radiation exposure control for certified and non- certified systems: (1) Exposure initiation: (A) 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; and (B) It shall not be possible to make an exposure when the timer is set to a "zero" or "off" position if either position is provided. (2) Exposure termination: (A) Means shall be provided to terminate the exposure at a preset time interval, preset product of current and time, a preset number of pulses, or a preset radiation exposure to the image receptor. (B) An x-ray exposure control shall be incorporated into each x-ray system such that an exposure can be terminated by the operator at any time, except for exposures of one-half second or less. (C) Termination of an exposure shall cause automatic resetting of the timer to its initial setting or to "zero". (3) Means shall be provided for visual indication observable at or from the operator's protected position whenever x-rays are produced. In addition, a signal audible to the operator shall indicate that the exposure has terminated. (4) With a timer setting of 0.5 seconds or less, the §11-45-120 45-109 difference between the maximum exposure time (Tmax) and the minimum exposure time (Tmin) shall be less than or equal to ten percent of the average exposure time (T), when four timing tests are performed: (Tmax - Tmin) < 0.10T (5) Exposure control location and operator protection: (A) Stationary x-ray systems shall be required to have the x-ray exposure control permanently mounted in a protected area, so that the operator is required to remain in that protected area during the entire exposure; and (B) Mobile and portable x-ray systems which are: (i) Used for greater than one week in the same location, i.e., a room or suite, shall meet the requirements of subparagraph (A); (ii) Used for less than one week in the same location shall be provided with either a protective barrier at least 6.5 feet (two meters) high for operator protection, or means to allow the operator to be at least twelve feet (3.7 meters) from the tube housing assembly while making exposures. (d) The coefficient of variation for exposure reproducibility shall not exceed 0.05 when all technique factors are held constant. This requirement shall be deemed to have been met if, when four exposures are made within a period of one hour at identical technique factors, the difference between the maximum exposure value (Emax) and the minimum exposure value (Emin) shall be less than or equal to ten percent of the average exposure: (Emax - Emin) < 0.10E (e) When the equipment allows a choice of x-ray tube current settings and is operated on a power supply as specified by the manufacturer for any fixed x-ray tube potential within the range of forty to one hundred percent of the maximum rating, the average ratios of exposure to the indicated milliampere seconds product obtained at any two consecutive tube current settings shall not differ by more than 0.10 times their sum: (X1 - X2) < 0.10(X1 + X2) where X1 and X2 are the average mR/mAs (C/kg/mAs) values obtained at each of two consecutive tube current settings. (f) Deviation of technique factors from indicated values shall not exceed the limits specified for that system by its manufacturer. In the absence of manufacturer's specifications the deviation shall not exceed ten percent of the indicated value. (g) Dental x-ray machines with a nominal fixed kilovolts peak of less than fifty kilovolts peak shall not be used to make diagnostic dental radiographs of humans. (h) Administrative controls: §11-45-120 45-110 (1) Patient and film holding devices shall be used when appropriate. (2) The tube housing and the position indicating device shall not be hand-held during an exposure. (3) The x-ray system shall be operated in such a manner that the useful beam at the patient's skin does not exceed the requirements of subsection (b). (4) Dental fluoroscopy without image intensification shall not be used. [Eff 11/12/99] (Auth: HRS §§321-10, 321-11, 321-71) (Imp: HRS §§321-1, 321-11(21), 321- 71)