Radiation Safety & Determining Need for Radiographs

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Ralf Fleming
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1 Radiation Safety & Determining Need for Radiographs

2 Guidelines for Radiographic Examination All radiation is harmful! These guidelines have been established to protect the patient and operator from unnecessary exposure These are simply guidelinesultimately it is the dentist s judgment that determines patient x-ray exposure Kodak Safety Guidelines- see learning activities

3 Think about some clinical situations where radiographs may be indicated?

4 Benefits & Importance of Dental Radiographs Importance- essential for diagnosis, detection, confirmation, baseline documentation, and evidence Benefits- primarily to detect disease; thus minimizing and preventing problems

5 What information can be detected from accurate radiographs? Missing teeth Supernumerary teeth Impacted teeth Dental caries Periodontal disease Retained roots Cysts/tumors Tooth abnormalities

6 The Professional s (that s you!) Commitment to the Public Knowledge, skill, and proficiency in technique is essential You have specific duties and responsibilities as a dental assistant and are a vital member of the dental team Professional goals & responsibilities: patient protection operator protection patient education operator competence operator efficiency production of quality radiographs

7 ALARA Concept ALARA concept: AS LOW AS REASONABLY ACHIEVABLE every reasonable measure should be taken to reduce exposure of radiation for the patient and operator

8 Patient Protection Prescribing x-rays (remember- *only the dentist can prescribe x-rays) The first step to reducing patient exposure is by proper prescribing of dental x-rays Taking x-rays for legitimate purposes only

9 Proper Equipment Filtration (inside of the tubehead- eliminates long or low energy wave lengths) Collimation (restricts size & shape of the x-ray beam) Positioning indicating device (PID) Thyroid collar & lead apron Fast film Film holding devices Exposure settings

10 Parts of an X-ray Machine Aluminum disks & collimator (inside) Positionindicating device (PID)

11 Additional Collimator Rectangular collimator (added to PID for further radiation reduction)

12 State & Federal laws State and Federal laws regulate x-ray equipment Dental machines must have 2.5 mm of aluminum filtration in the tube head if operating above 70 kvp A collimator, which is a lead plate inside the opening of the tube head, can be round or rectangular but must be no more than 2.75 inches in diameter; there are also collimators that can be added to the PID The PID, which is an extension of the tube head and used to direct the beam, can be either 8 inches or 16 inches; the long PID 16 is preferred and the rectangular type is most effective in reducing exposure to the patient

13 Thyroid collar & Lead apron Thyroid collar protects the thyroid gland (highly sensitive) Both a thyroid collar and lead apron should be used by the patient while exposing intraoral radiographs

14 Cells Most Sensitive to Radiation Highly sensitive- lymphoid organs, bone marrrow, reproductive organs, intestines, skin & cornea of the eye

15 Cells Least Sensitive to Radiation Least sensitive- lungs, kidneys, liver, muscle, nerve, mature bone

16 Latent Period The latent period is the time that elapses between the exposure to ionizing radiation and the appearance of clinical symptoms; this time can vary from hours to years Long term effects of radiation- there is no specific radiation disease. However, cancer can be caused by radiation and is one example of long term effects of radiation.

17 Fast Film Types of film speed used in intraoral radiography: E-Speed- requires ½ the exposure time of D- speed film and has comparable image contrast and resolution and is less exposure to the patient F-Speed- newer film; 50% less radiation than D and 20% less radiation than E speed film **D speed film is no longer recommended Fast film is available for both intraoral and extraoral radiography

18 Film Holding Devices Effectively reduce patient exposure by stabilizing the film in the mouth Also, the patient does not have to hold the film (not recommended)

Exposure Settings A setting of 7 to 15 ma s and 70-90

19 Exposure Settings A setting of 7 to 15 ma s and kvp is recommended to keep patient exposure to a minimum

20 Operator Protection It is imperative the operator avoid the primary x- ray beam (stand to the side at an angle) Maintain adequate distance during exposure; at least 6 ft.; standing behind a protective barrier (such as a wall) is also recommended Operator must never hold a dental film or tubehead during exposure

21 Monitoring Radiation Personnel monitoring can be done using a film badge (measured monthly)

22 Exposure Guidelines Radiation standards state the maximum amount of radiation a person can receive: Maximum Permissible Dose (MPD) this is the amt of radiation for a set time (for example- a month) Maximum Accumulated Dose (MAD)- this is the amt of radiation for a lifetime

23 MPD MPD for an occupational worker is 5 *rems a year MPD for a nonoccupational worker is.1 rem per year MPD for a pregnant occupational worker is.1 rem per year *A rem is a unit used to measure a dose of radiation

24 MAD The MAD is the lifetime dose of radiation; this is calculated using the person s age (N) Formula: (N-18) x 5 rems a year Example: (35 years old 18) X 5 = 85 rems 18 is represented for the minimum age to expose radiographs

25 Quality Assurance Quality assurance in film processing is a vital part of reducing patient exposure; for example: poor quality x-rays often require a retake of the film (proper processing of films will be discussed later)

Kodak Dental Radiography Series. Radiation Safety in Dental Radiography. Dental

Kodak Dental Radiography Series Radiation Safety in Dental Radiography Dental Radiation Safety in Dental Radiography The goal of dental radiography is to obtain diagnostic information while keeping the