Composite and adhesive dentistry have seen an explosion both in their use and in the science that has allowed them to become the most commonly placed restorative materials in a huge number of practices. Careful science and research from multiple sources has allowed tooth-colored materials to move from the realm of “pretty but unpredictable” into the category of “what I reach for first” for a large number of doctors.
However, one of the factors that has really changed in recent years is curing lights, and I don’t think they are factored in as heavily in the success or failure of bonded restorations as they should be.
Most of today’s composites use camphorquinone as the photoinitiator. This chemical, often referred to as CPQ, requires a specific wavelength (color) of light to trigger it into starting polymerization of the composite resin. Because LEDs can be fine-tuned to produce just a specific wavelength or range of wavelengths, these curing devices now produce light where every photon that’s produced can be used in the curing process.
This translates to better and more efficient curing. Many non-LED curing devices, such as fast halogen lights, produce lots of photons that are wasted because they are outside the range used by CPQ.
The use of CPQ is very common by most manufacturers, but there are a few adhesive materials that use a different photoinitiator. Because of that, and the specifics of LEDs, there’s potential for a material to not be cured by a device designed to work only with CPQ. Fortunately, because LEDs can be created to produce different wavelengths, there are now several devices that can cure every resin-based material on the market. (To find out which photoinitiator your materials use, be sure to ask the manufacturer.)
We have seen an explosion in the amount of technology and the resulting equipment required to deliver it. If you’re lucky enough to have built a new office lately, you’ve been able to plan for this and avail yourself of more counter space. Dental curing lights have decreased dramatically in size because of the proliferation of LED devices. This means more room to work when you need it most.
One of the things about curing is the light needs to be as close and as parallel to the restoration as possible. If the light is even a few millimeters away, it can drastically reduce the curing efficiency, resulting in a composite that’s only partially cured. A resin that has undergone this type of curing is much more likely to cause sensitivity and have a much shorter clinical lifespan.