Dental Radiography Exam Notes

Digital Radiography

  • Primary advantage: Reduces radiation to the patient.

  • Contrast in a digital image is primarily controlled by kVp.

Inverse Square Law

  • When changing from an 8-inch PID to a 16-inch PID, the inverse square law is used to determine beam intensity.

Effects of Radiation

  • Radiation has the potential to cause harmful biologic changes.

PID Shapes and Radiation Exposure

  • Rectangular-shaped PIDs reduce patient radiation exposure by up to 70% compared to round PIDs.

  • The rectangular PID shape most effectively reduces patient exposure to radiation.

Cells and Radiation

  • Cells exposed to radiation that may be associated with leukemia: Somatic cells.

Radiation Monitoring

  • Personnel radiation monitoring devices are worn to record the occupational exposure received by the operator.

  • Personnel monitoring for radiation exposure is done by wearing a dosimeter.

X-ray Tubehead

  • Leaded-glass housing prevents x-rays from escaping the tubehead.

Operator Distance

  • Minimum distance the operator should stand from the tube head when exposing radiographs: 6 feet.

Education and Certification

  • The Consumer-Patient Radiation Health and Safety Act was established to address the education and certification of operators of radiographic equipment.

Ionizing Radiation

  • To produce ionizing radiation, an atom must lose a proton.

Shielding

  • Dental healthcare personnel can best shield themselves from radiation during patient exposure by standing behind a drywall barrier.

Measuring Radiation Injury

  • Radiation injury can be measured by dose rate.

Factors Determining Radiation Injury

  • The amount of tissue irradiated is used in determining the degree of radiation injury.

Wavelength and Energy

  • The shorter the wavelength of electromagnetic radiation, the greater the energy.

Landmarks for Image Mounting (Maxillary Posterior)

  • Floor of the maxillary sinus is useful when mounting images in the maxillary posterior area.

Artificial Radiation Exposure

  • The most common artificial radiation exposure comes from medical radiation.

Radiosensitivity

  • The most highly radiosensitive tissue is reproductive.

Long-Term Effects of Radiation

  • Long-term effects of exposure to radiation may be associated with birth abnormalities.

Radiation Protection Methods

  • To minimize exposure to the radiographer, employ barrier, monitoring device, and appropriate operator position.

Dental X-ray Prescription

  • Dental x-rays should be prescribed when the benefits outweigh the risk of harm.

Leakage Radiation

  • Leakage radiation is defined as any radiation that is emitted from the tubehead.

Rectangular Collimator

  • The purpose of a rectangular collimator is to reduce radiation to the patient.

Landmarks for Image Mounting (Maxillary Central)

  • Anterior nasal spine is useful when mounting images in the maxillary central area.

ALARA Concept

  • Using the ALARA concept as a guideline for radiographs includes all of the following EXCEPT using a circular PID.

Electron Speed

  • kVpkVp affects the speed of the electrons emitted from the tubehead.

Aluminum Filtration

  • For x-ray machines operating at or below 70 kVpkVp, the total aluminum equivalent filtration must be a minimum of 1.5 mm.

Operator Protection

  • Structural shielding is used to minimize x-radiation exposure to the operator.