The Effect of Dental Curing Light on Eyes

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.

Resin Fillings

Resin composite fillings are made of a unique material that looks like the natural tooth, contains no mercury, and can easily be shaped to fit a cavity.

Function of Curing Light

Once the resin mixture is placed inside the patient's mouth it has to be cured, or hardened like ceramic. This means that a certain type of light must be shone onto the filling in order to harden it and bond it to the tooth.


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.

Eye Danger

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.


In order to stop the light from reaching and damaging a patient's eyes, a protective shield should be placed around the light so that it may only go into the mouth and not reflect up into the patient's face.