We usually are asked "What is that?" from our patients who are watching us wave this "blue wand" over their mouth while getting fillings. This "blue wand" is a curing light. This light is used for polymerization of light-cured resin-based composites or, in other words, the white filling that we put in a tooth. 

A dental curing light is used to cure or harden a white tooth colored filling. Areas of improvement took place in the 1990's. Resin composites were better and the lights became stronger. The plasma light was introduced in 1998. It was a high-intensity light with a fluorescent bulb claiming to cure in 3 seconds. There were negative aspects to this light: high priced, actually cured in longer times than 3 seconds, and it was expensive to maintain. This brought about another light source technology, LED light.

The original LED lights had narrow emission spectrum and low power intensities, necessitating long curing times. This issue was overcome by 2nd generation curing lights with high power intensity. However, they maintained narrow emission spectrum, which restricted them to activate only camphorquinone, and thus could not fully polymerize some composite materials. Third generation curing lights feature broad emission spectrum (380nm to 515nm), along with high irradiance in the range of 1000mW/cm2 and higher, reportedly allowing these lights to light-cure all composites without restriction.

Using a curing light accomplishes two things. In the first place, it makes sure that the resin cures properly and adheres evenly. When applying fillings, this is critical to keep the filling in place in the mouth. For sealants, the curing light limits the risk of cracks and other problems with the sealant. With adhesives for implants and braces, the rapid, even cure is also designed to limit problems in the future.

The dental curing light also increases patient comfort by rapidly curing resins so that the patient is not forced to sit in discomfort while the resin sets. Since the mouth usually needs to be held open wide and may be dry for the procedure, patients usually want the procedure to end as quickly as possible so that they can close their mouths and remoisturize the dried oral membranes. Using a curing light gets patients in and out of the portable folding chair quickly so that the experience of irritation and pain is limited.