Radiology

• Same Size
• Same Shape
• Proper Density and Contrast

• 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

Short distance between object and film

Short distance between object and film

• Bisecting- one edge against the tooth
• Paralleling- parallel to long axis of tooth

• Paralleling- beam passes through both tooth and film at 90 degrees
• Bisecting- beam passes through the imaginary bisecting line dividing tooth and film

• Bisecting- short cone (8 in)
• Paralleling- long cone (12 in)

Trouble estimating bisector

Less distortion

Paralleling

Bisecting

Paralleling

• Tip of nose
• Ala of nose
• Inner canthus
• Outer canthus

• 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

Alerted the dental profession to the dangers of radiation exposure. Father of the Science of Radiation Protection

• Causes fluorescence in certain cases
• Travels short distances
• Consists of negative charged particles
• These particles have mass

• 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

The ability of x-rays to penetrate some objects better than others

Electromagnetic Radiation