2. Learning Objectives
Lesson 1.1: Radiation History
1. Define the key terms associated with dental radiation.
2. Summarize the importance of dental images.
3. List the uses of dental images.
4. Summarize the discovery of x-radiation.
5. Recognize the pioneers in dental x-radiation and their
contributions and discoveries.
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3. Learning Objectives
Lesson 1.1: Radiation History (Cont.)
6. List the highlights in the history of x-ray equipment
and film.
7. List the highlights in the history of dental
radiographic techniques.
8. List the highlights in the history of digital imaging.
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4. Introduction
Purpose
To introduce basic dental radiography terms
To detail the importance of dental radiographs
To review the history of x-radiation
The dentist relies on the dental radiographer to capture a
radiographic image as accurately as possible in order for a
proper diagnosis to be made.
The dental radiographer will also be responsible for
documenting the number and type of radiographs taken in
the patient’s clinical record under a dated entry.
It is important that the dental radiographer have a thorough
knowledge of x-radiation, since x-ray images are a necessary
component of patient care.
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5. Dentistry and X-Radiation:
Basic Terminology
Radiation
Energy carried by waves or streams of particles
X-radiation
High-energy radiation produced by the collision of a beam of
electrons with a metal target in an x-ray tube
X-ray
A beam of energy that has the power to penetrate substances
and record image shadows on photographic film
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6. Dentistry and X-Radiation:
Basic Terminology (Cont.)
Radiology
Radiology is the science or study of radiation as
used in medicine; a branch of medical science that
deals with the use of x-rays, radioactive
substances, and other forms of radiant energy in
the diagnosis and treatment of disease.
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7. Dentistry and X-Radiation:
Basic Terminology (Cont.)
Radiograph
This is a picture (visible photographic record) on film produced
by the passage of x-rays through an object or body; also called
x-ray film. In practice, often called an “x-ray”; this is not correct.
X-ray (also x ray) is a term that refers to a beam of energy.
Dental radiograph
A photographic image produced on film by the passage of x-
rays through teeth and related structures
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8. Dentistry and X-Radiation:
Basic Terminology (Cont.)
Radiography
The art and science of making radiographs by the exposure of
film to x-rays
Dental radiography
The production of radiographs of the teeth and adjacent
structures by the exposure of film to x-rays
Dental radiographer
Any person who positions, exposes, and processes x-ray film
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9. Dentistry and X-Radiation:
Basic Terminology (Cont.)
Image
A picture or likeness of an object
Image receptor
A recording medium; examples include x-ray film, phosphor
plate, or digital sensor
Imaging, dental
The creation of digital, print, or film representations of
anatomic structures for the purpose of diagnosis
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10. Importance of Dental Images
In dentistry, dental images enable the dental
professional to identify many conditions that may
otherwise go undetected and to see conditions that
cannot be identified clinically.
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11. Uses of Dental Images
Detect lesions
Confirm or classify suspected disease
Localize lesions or foreign objects
Provide information during dental procedures
Evaluate growth and development
Illustrate changes secondary to caries, periodontal
disease, trauma
Document the condition of a patient
Aid in development of a clinical treatment plan
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12. Roentgen and the Discovery of X-
Rays
Wilhelm Conrad Roentgen – 1895
Roentgen was experimenting with vacuum tubes and fluorescent
screens.
He noticed the screens were glowing even though they were several feet
from the tube.
He determined that some mysterious ray was causing the screens to glow.
After replacing the fluorescent screen with photographic plates, he was able
to permanently capture images.
He placed his wife’s hand on a photographic plate and exposed her to the
rays for 15 minutes to show that he was able to permanently capture the
outline of her bones.
This event was also recorded as the first radiograph of the human body.
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13. Pioneers in Dental X-Radiation
Otto Walkhoff – 1895
Made the first dental radiograph
Exposed his own mouth on a photographic plate for 25 minutes
W.J. Morton – 1895
Made the first radiograph using a skull
Morton, in team with Thomas Edison, gave warning of the adverse effects
of x-rays.
C. Edmund Kells – 1896
Exposed the first dental radiograph in the United States using a living
person
Kells developed cancerous tumors due to exposing his fingers and hands
to x-rays everyday. This led to the loss of his fingers, his hand, and later
his arm.
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14. Pioneers in Dental X-Radiation (Cont.)
William H. Rollins
Developed the first dental x-ray unit
Frank Van Woert
First to use film in intraoral radiography
Howard Riley Raper
Established the first college course in radiography for dental students
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15. History of Dental X-Ray
Equipment
William Coolidge – 1913
Developed the first hot-cathode x-ray tube
Victor X-Ray Corporation – 1923
Oil immersion of the tubehead
1957
Variable kVp machine
1966
Recessed long-beam tubehead
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16. History of Dental X-Ray Film
1896 to 1913
Hand-wrapped glass photographic plates or film
Eastman Kodak – 1913
Manufactured prewrapped intraoral film
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17. History of Dental
Radiographic Techniques
C. Edmund Kells – 1896
Introduced paralleling technique
Weston Price – 1904
Bisecting technique
Howard Riley Raper – 1925
Refined original bisecting technique and introduced the bite-
wing technique
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18. History of Dental
Digital Imaging
Radiographs have been produced using radiographic film for well
over a century.
Traditional radiography is being replaced by digital imaging.
Digital imaging allows for instant and easy transmission of images
and electronic storage.
1987 – First intraoral imaging sensor
1989 – An article describing direct digital imaging technology
published in U.S. dental literature
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Editor's Notes
The dentist relies on the dental radiographer to capture a radiographic image as accurately as possible in order for a proper diagnosis to be made.
The dental radiographer will also be responsible for documenting the number and type of radiographs taken in the patient’s clinical record under a dated entry.
It is important that the dental radiographer have a thorough knowledge of x-radiation, since x-ray images are a necessary component of patient care.
Pronounce each key term correctly for the class.
Pronounce the key term correctly for the class.
Pronounce these terms correctly for the class.
Pronounce each key term correctly for the class.
Pronounce each key term correctly for the class.
Many dental diseases and conditions have no clinical signs or symptoms and may go undetected without the use of dental images.
Dentists should weigh the benefits of dental images against increasing a patient’s exposure to radiation.
These are all-important factors to keep in mind when your patient is against having dental radiographs taken.
After replacing the fluorescent screen with photographic plates, he was able to permanently capture images.
He placed his wife’s hand on a photographic plate and exposed her to the rays for 15 minutes to show that he was able to permanently capture the outline of her bones.
This event was also recorded as the first radiograph of the human body.
Refer to Figures 1-1 and 1-2 in the text.
Walkhoff produced the first recorded dental radiograph by exposing his own mouth on a photographic plate for 25 minutes.
Kells developed cancerous tumors due to exposing his fingers and hands to x-rays everyday. This led to the loss of his fingers, his hand, and later his arm.
Morton, in team with Thomas Edison, gave warning of the adverse effects of x-rays.
Rollins was not only a practicing dentist, but he also had a medical degree from Harvard University.
Van Woert pioneered the first use of Kodak film.
Raper wrote many textbooks regarding radiography. He was the first to be given the title “Professor of Radiology.”
Refer students to Table 1-1, which lists highlights in the history of dental radiography.
Coolidge received the U.S. patent to allow for the tungsten filament located in x-ray tubes. This allowed for better visualization of dental anatomy and tumors.
Refer students to Figure 1-4.
Can light pass through film packets? (No, only x-rays can.)
The operator decides which technique to use according to the patient’s needs.
Digital imaging technology has become widely accepted and has evolved with improvements in sensor design and supporting technology.
