Discovery of x-ray
Professor Wilhelm Conrad Roentgen
* 1895 discovered the first example ionizing radiation
* the key to his discovery was device called a Crooke’s tube.
Scientists and Researchers
* Dr. Otto Walkhoff
* the first to expose a prototype of a dental radiograph. * accomplished by covering a small, glass photographic plate with black paper to protect it from light and then wrapping it in a sheath of thin rubber to prevent moisture damage during the 25 minutes he held it in his mouth.
Made the first dental radiograph
* Dr. William Herbert Rollins
* one of the first to alert the profession to the need for radiation hygiene and protection and is considered by many to be the first advocate for the science of radiation protection
* Dr. William James Morton
* took radiographs on skulls and revealed an impacted tooth, which was otherwise undetectable clinically
* Dr. Edmund C Kells
* Was the first to put the radiograph to practical use and may have taken the first radiograph on a living subject. * He was a New Orleans dentist, demonstrated the first film taken on a live patient 3 months later in 1896. Kells was a prolific inventor and writer, in dentistry and other field. (He was one of the first to use electricity in dental office). * He often held the film in the patient’s mouth during the long exposure, or used his hand as the object while adjusting the exposure, since these early machines had unpredictable emissions. Unfortunately, he did not realized the dangers from his own continual X-ray exposure and developed cancer in his right hand, which later progressed through his arm and shoulder. * After forty-two operations, the intense suffering caused him to take his own life in 1928, at the age of 72.
Evolution of the Dental X-ray Machine
* 1913: Coolidge hot cathode vacuum tube, invented by Dr. W. D. Coolidge * Mid-1950s: Variable kilovoltage machines were introduced that allow for different penetrating abilities of the x-beam * 1966: Recessed PID was introduced
* 1974: Federal government began regulating the manufacture and installation of all dental x-ray machines * State and local governing agencies also set guidelines on the safe installation and use of dental x-ray equipment * Today: Dental x-ray machines are safe, compact, easy to position, and simple to operate
* William David Coolidge
* Introduced the hot cathode tube
* The x-ray output of the Coolidge tube could be predetermined and accurately controlled
* Howard Riley Raper
* Wrote the first dental radiology textbook “Elementary and Dental Radiology” * Introduced bitewing radiographs in 1925
Components, functions and maintenance of the x-ray machine:
Early dental x-ray machines were an electrical hazard because of the open uninsulated high-voltage supply wires. Shockproof dental x-ray machine introduced by Coolidge and General Electric in 1919 The x-ray tube and high-voltage transformer were placed in an oil-filled compartment that acted as a radiation shield and electrical insulator. Changes have been made to restrict the size of the x-ray beam. * Replacement of the pointed cone through which x-rays pass from the tube head toward the patient by open cylinders * Position Indicating Device (PID) functions to direct the x-ray beam * Available as a cylinder or rectangular lead-lined
* Rectangular limits the size of the x-ray beam that strikes the patient to the actual size of the image receptor. Extension Arm
Dental x-ray machine parts:
The standard structural parts of the dental x-ray machine include: * control panel (usually mounted behind a protective shield) * tube head, which houses the dental x-ray tube
* flexible extension arm from which the tube head is suspended The Control Panel is in...