A dental curing light is a piece of dental equipment that is used for polymerization of light cure resin based composites.[1] It can be used on several different dental materials that are curable by light. The light used falls under the visible blue light spectrum. This light is delivered over a range of wavelengths and varies for each type of device. There are four basic types of dental curing lights; Tungsten halogen, light-emitting diode (Dental Curing Light), plasma arc curing (PAC), and laser. The two main dental curing lights are the halogen and LED.

In the early 1960s, the first light curing resin composites were developed.[2] This led to the development of the first curing light. The first dental curing light, called Nuva Light, was developed by Dentsply/Caulk in the 1970s. Nuva Light used ultraviolet light to cure resin composites; it was discontinued due to this requirement, as well as the fact that the shorter wavelengths of UV lighting used did not penetrate deeply enough into the resin to adequately cure it.[3]

During the early 1980s, advances in the area of visible light curing took place, which ultimately led to the creation of a curing device that uses blue light. The next type of curing light developed was the quartz-halogen bulb;[4] this device had longer wavelengths of the visible light spectrum and allowed for greater penetration of the curing light and light energy for resin composites.[3] The halogen curing light replaced the UV curing light.

The 1990s presented great improvements in light curing devices. As dental restorative materials advanced, so too did the technology to cure these materials; the focus was to improve the intensity in order to be able to cure faster and deeper. In 1998 the plasma arc curing light was introduced.[5] It uses a high intensity light source, a fluorescent bulb containing plasma, in order to cure the resin-based composite, and claimed to cure resin composite material within 3 seconds. In practice, however, while the plasma arc curing light proved to be popular, negative aspects (including, but not limited to, an expensive initial price, curing times longer than the claimed 3 seconds, and expensive maintenance) of these lights resulted in the development of other curing light technologies.

The latest advancement in technology is the LED curing light. While LED curing lights have been available since the 90s, they were not widely used until the frustrations presented through ownership of plasma arc lights became unbearable. While the LED curing light is a huge step forward from the initial curing light offerings, refinements and new technologies are continually being developed with the goal of quicker and more thorough curing of resin composites.

The Tungsten halogen curing light, also known as simply “halogen curing light” is the most frequent polymerization source used in dental offices.[6] In order for the light to be produced, an electric current flows through a thin tungsten filament, which functions as a resistor.

These curing lights use one or more light-emitting diodes [LEDs] and produce blue light that cures the dental material. LEDs as light-curing sources were first suggested in the literature in 1995.[8] A short history of LED curing in dentistry was published in 2013.[9] This light uses a gallium nitride-based semiconductor for blue light emission.[6]