Card Set Information

2012-08-24 13:56:57

Everything from the Study Guide
Show Answers:

  1. Characteristics of a Shadow Image
    • Same Size
    • Same Shape
    • Proper Density and Contrast
  2. Principles of Shadowcasting
    • Long Cone; long source distance from target to object
    • Short distance between tooth and film
    • Film and object parallel
    • X-ray beam 90 degree to long axis of film and object
  3. Which is the only principle bisecting does adhere to?
    Short distance between object and film
  4. Paralleling does not follow which principle?
    Short distance between object and film
  5. How is the film positioned in paralleling and in bisecting?
    • Bisecting- one edge against the tooth
    • Paralleling- parallel to long axis of tooth
  6. How is the X-ray beam directed in paralleling and in bisecting?
    • Paralleling- beam passes through both tooth and film at 90 degrees
    • Bisecting- beam passes through the imaginary bisecting line dividing tooth and film
  7. Which is the long cone and which is the short cone?
    • Bisecting- short cone (8 in)
    • Paralleling- long cone (12 in)
  8. What is the disadvantage of bisecting?
    Trouble estimating bisector
  9. What is the advantage of paralleling?
    Less distortion
  10. Which technique gives us the best image?
  11. Which technique is good for shallow palates?
  12. Which requires a film holder?
  13. Facial landmarks
    • Tip of nose
    • Ala of nose
    • Inner canthus
    • Outer canthus
  14. Roentgen
    • Worked in dark lab to see stream of colored light
    • Noticed flourescent screen glowing
    • Differential absorption
    • Prism(deflect ray), Lens(to focus), Magnet(to bend), and Pinwheel(to detect mass), but nothing happened in any of these
  15. Rollins
    Alerted the dental profession to the dangers of radiation exposure. Father of the Science of Radiation Protection
  16. Cathode Ray Properties
    • Causes fluorescence in certain cases
    • Travels short distances
    • Consists of negative charged particles
    • These particles have mass
  17. X-Ray Properties
    • Can cause a fluorescent screen to glow
    • Can affect a photographic plate
    • Invisible
    • Travel long distances at the speed of light
    • Have no mass- pure E
  18. Differential Absorption
    The ability of x-rays to penetrate some objects better than others
  19. In what category of radiation do x-rays belong?
    Electromagnetic Radiation