As mentioned, there are 4 types of dental curing lights. All of them are capable of achieving the blue wavelength that is intended for polymerization. Among the 4, the two most common are LEDs and halogens.
Tungsten Halogen
One of the early dental curing lights is the tungsten halogen curing lights. Developed in the 1980s, they have been the replacement of UV lights by utilizing the blue wavelength. To generate the light, the halogen bulb needs to be energized.
The filament will then reach a temperature of 3,000 Kelvin or roughly 2,700 degrees Celsius. At this point, the visible light will then have a wavelength of 400 to 500 nanometers, which indicate the range for the blue light. With such a very high temperature, a powerful ventilating fan, which is already a part of the machine, is very much necessary.
So far, the technology is proven to be very useful until the emergence of a much more efficient generation of light such as the other 3 types. With the generation of great heat in halogen bulbs to achieve light, the ventilation fan is being used to its full potential just to cool down the operation, and thus, unnecessary noise from its mechanical action is also being produced in the process.
Plasma Arcs
In the 1990s, there have been improvements in dental light-curing devices. A fluorescent bulb that contains plasma generates a light source of high intensity. According to the claims, within just 3 seconds, the resin composite material will be ‘cured.’
The bulb is a high-pressure vessel made from aluminum oxide. It contains xenon gas that is highly energized under a pressure of 150 psi. While the arc is made between 2 energized electrodes, the reflectors direct a focused beam. It is, without a doubt, effective, but the procedure costs a lot.
Lasers
If you are familiar with argon lasers, they are usually used for medical practices. More commonly, you might have encountered that procedure in an eye clinic. Due to its effectiveness in generating such a focused light source, it is seen as effective for dental curing light.
The argon laser utilizes the noble gas ‘argon’ as the medium for the light to pass through. The light will become more concentrated and, thus, termed as ‘laser.’ However, using lasers can be too much on the budget for dental applications.
LEDs Or Light-Emitting Diodes
Although lasers and plasma arcs are more efficient than tungsten halogen lights, they are very impractical, financially speaking. And here comes the newcomer, the light-emitting diode or LED. This semiconductor component is capable of emitting a wide spectrum of light without wasting energy in generating heat or having an expensive operating cost.
Since there is not much energy wasted as heat, small ventilation fans can be enough. Even with all the great things about LEDs, they too have limitations. They cannot generate more power compared to the other 3, but with numbers, that can be compensated.
They rely on chemical reactions for luminescence and might be prone to be busted if excessive energy is flown through the bulbs. Throughout the years, LEDs are still developing yet have now become the top light source both commercially and industrially. There is no wonder that even the development of new dental curing lights is gearing more towards the LED technology.