I would like to comment on what I think are a few mis-understandings about dental curing lights. These are the units that cause dental materials, such as composites, sealants, and cements, to set or polymerize in the mouth. These units produce a visible blue light that these materials absorb, causing them to set. The first point is that the unit produces visible light, not ultraviolet light. Every dental curing light today is a visible blue light and does not produce ultraviolet light, which would not generally be safe for you, or the patient. So these lights are not UV lights. The confusion arises from the fact that dental curing lights once were UV lights. The inventor of this system was not familiar with visible light curing chemistry at the time, and therefore selected UV chemistry, which was quickly replaced by blue, visible light curing chemistry.
Several clinicians and researchers speak of how the material reacts to this instant cure, whether the material has internal stresses built-up, or not, and whether a ramping up of curing is preferred to reduce these "internal" stresses. There is some disagreement about this. However, I think this misses the point that it should be the heat build-up in the tooth and surrounding tissue that we should be of most concern.