Dentists use curing lights to harden composite material used for tooth fillings or bonding. The four different types of curing lights are LED, plasma, laser and halogen. The light waves produced by the curing light initiate a change within the composite and enable it to harden and bond with the tooth. The curing (hardening) process is quick, typically between 10 to 40 seconds, allowing the patient to leave the dentist office without worrying about damaging a filling.
Dental LEDs use blue light. The dental materials used determine the intensity of light that must be used. According to a "Journal of the American Dental Association" article titled "Curing Performance of a New-Generation Light-Emitting Diode Dental Curing Unit," the blue light used in dental LED lights ranges from 400 to 500 nanometers.Dental LED curing lights work just as well as halogen curing lights, and they don't generate as much heat. Laser lights also produce more heat, which increases the potential for damage to gingival tissue and inner tooth soft tissue.
It's one of the old realities of medicine that almost every procedure has some side effect. Dentistry is no different. In an effort to be safer by eliminating the use of silver amalgam fillings (which contained mercury, a poisonous metal), resin fillings were developed and used. However, the curing process for these filling can also be dangerous to a patient unless proper precautions are taken.
There are two main choices of light that will react with resin composite fillings, according to the American Dental Association. One is ultraviolet light, and the other is visible blue light. Both of these lights, while necessary to harden the fillings, can damage a patient's eyes.Of these two types, ultraviolet light is more dangerous to a person's eyes. It can result in macular degeneration, and has been linked to cancer. Blue light may also degenerate a person's eye--just not as quickly as ultraviolet light.