1. Introduction to Oral Radiology

• November 8th 1895


  Wilhem Conrad Roentgen in his laboratory using Crooke's tube. Wuzburg, Germany
• February 1, 1896


  Radiograph was made by Dr. Walter Konig of Germany.
• December 28, 1895

  Roentgen presented his findings to the Wurzburg Physical-Medical Society.
• January 1896


  a dentist, Dr. Otto Walkhoff in Braunschweig, Germany made the first dental radiograph
• 25 minutes


  How many minutes of exposure has needed to create an image of an intraoral radiograph?
• What is intraoral radiograph

  A glass photographic plate wrapped in black rubber dam and with an exposure of 25 minutes
• Who produced intraoral radiograph

  Dr. Otto Walkhoff
• Dr. Edmund Kells


  Who used impression compound to stabilized the film during film
• 7 weeks


  How many weeks does Wilhem Roentgen locked himself in laboratory for the experiment?
• In those seven weeks, Roentgen discovered that:

  -Although the new rays were invisible, they caused fluorescence in certain substances

  -They darkened photographic plates

  -They were propagated in straight lines

  -Their behavior differed fundamentally from that of cathode rays

  -They were neither reflected nor refracted by (then known) experimental methods

  -They were not deviated by the influence of electro-magnetic fields.

  -Air traversed by the rays was made electrically conductive.

  -He investigated the startling penetration of the rays through many materials and observed the "hardening" of x-ray beams after penetrating several absorbers.

  -He noted that different types of scattered and of secondary radiations were produced.
• It is thought that the first dental radiograph made in the

  United States and was by Dr. Edmund Kells of New Orleans, Louisiana.
• Cathode Rays


  are streams of electrons observed in vacuum tubes, i.e. evacuated glass tubes that are equipped with at least two electrodes, a cathode (negative electrode) and an anode (positive electrode) in a configuration known as a diode When the cathode is heated, it emits some radiation which travels to the anode.
• Cathode Ray Tubes

  -The glass emits here a green glow.

  -In this high vacuum, used in many Crookes tubes, X-Rays are produced.
• On February 22nd, 1890 in Philadelphia

  PA, A.W. Goodspeed and William Jennings produced this radiogram by placing the coins on top of a glass photographic plate.
• Early Radiographs are called

  good speedograms
• Philip vonLenard

  (1862-19470)

  Who grasp, was against and Resented the findings of Oral Radiograph?
• 1885-1889

  What year Heinrich Rudolph Hertz became the first person to broadcast and receive radio waves, and to establish the fact that light was a form of electromagnetic radiation.
• Heinrich Rudolph Hertz


  became the first person to broadcast and receive radio waves, and to establish the fact that light was a form of electromagnetic radiation.
• 300 Years


  How many years of discoveries leading to roentgen's work?
• on 1600, Gilbert's De Magnete


  created the foundation for the sciences of magnetism and electricity.
• 1675, Newton


  built a more efficient electrostatic generator with a rotating glass sphere.
• 1729, Gray


  distinguished conductors of electricity from nonconductors.
• 1750, Franklin

  defined positive and negative electricity.
• 1785, Morgan


  in vacuum experiments, possibly produced x-rays.
• 1800, Volta


  constructed the first electrical battery, the Voltaic pile.
• 1820, Oersted


  discovered the link between electricity and magnetism.
• 1827, Ohm


  formulated Ohm's law, stating the relation between electric current, electromotive force, and resistance.
• 1821, Faraday and Henry


  discovered electromagnetic induction.
• 1850, Plucker


  observed green-glass fluorescence opposite the negative electrode in a vacuum tube.
• on 1860

  Toepler, Holtz, and Wimshurst
• 1873, Maxwell


  published his famous equations in the book,

  "Treatise on Electricity and Magnetism ."
• 1879, Crookes


  found that cathode rays can be deflected by a magnet, and believed that he was dealing with "a fourth state of matter."
• William Morton


  (1845-1920)-New York dentist

  - Also credited (along with Kells) with the first dental radiograph exposed in the United States
• William H. Rollins


  (1852-1929)-Boston Dentist

  -Publish more than 200 articles on radiation effects and safety between 1896 and 1904
• DR. Frank Van Woert is


  one of the first to use Kodak film (instead of glass plates).
• Dr. Howard Riley Raper


  He was the inventor of the bitewing radiograph in 1924, and the first to write a textbook on the subject (Elementary and Dental Radiology, 1913).

  -Early dental x-ray unit
• Dr. Edmund Kells


  Who developed cancer because he accidentally held films in place with his hands
• What causes roentgen's death

  carcinoma in the bowel caused by the films in the x-ray
• Dr. Edmund Kells


  After 42 operations, his 20 yrs battle against cancer about come to an end. Contributed over 150 articles to dental journals. On May 7, 1928, at age 72, he committed suicide.
• Heinrich Rudolph Hertz


  became the first person to broadcast and receive radio waves, and to establish the fact that light was a form of electromagnetic radiation.