The first dental radiograph was produced using an exposure time of:
a. 0.5 second.
b. 1 minute.
c. 5 minutes.
d. 25 minutes.
e. 1 hour.
d. Dr. Otto Walkhoff, a German physicist, was the first to expose a prototype of a dental radiograph. This was 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 that he held the film in his mouth.
You might also like to view...
In which decade was acupuncture first widely publicized in the United States?
a. 1930s b. 1950s c. 1970s d. 1980s
Which of the following are characteristics of nonabsorbable sutures?
A. They are made of a sterile strand of collagen fibers. B. They are used for the deep inner layers of the wound. C. They must be removed after substantial healing has taken place. D. They do not have to be removed after the wound has healed. E. They are used when there is considerable stress on the incision.
When generating ideas during decision-making, what is the most important task?
A) Separate ideas into possible and probable. B) Separate ideas into good and bad. C) Aim for quantity of ideas. D) Aim for quality of ideas.
What is the epiphysis?