
Concept explainers
Visible-Light Curing in Dentistry
An essential part of modern dentistry is visible-light curing (VLC), a procedure that hardens the restorative materials used in fillings, veneers, and other applications. These “curing lights" work by activating molecules known as photoinitiators within the restorative materials The photoinitiators, in turn, start a process of
Figure 25-50
An intense beam of light cures or hardens, the restorative material used to fill a cavity. (Problems 109, 110, 111, and 112)
The most common photo initiator is camphoroquinone (CPQ). To cure CPQ in the least time, one should illuminate it with
More recently, VLC units have begun to use LEDs as their light source These lights stay cool, emit nearly all of their energy output as visible light at the desired wavelength, and provide light with an intensity as high as 1000 m W/cm2, which is about 10 times the intensity of sunlight on the surface of the Earth.
112 • Assuming the light from the VLC unit has a beam 0 50 cm in diameter, how much energy does the light deliver in 20 seconds?
- A. 0.025 J
- B. B 3 9 J
- C. C 63 J
- D. D 5000 J

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Chapter 25 Solutions
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