LED curing lights--what's new?

Technological changes to blue light-emitting diode (LED) light-curing units have taken place at an accelerated rate. The lighting industry, however, has not yet improved output levels of blue chip design used in dental LED units as quickly. In fact, the same 5 watt source has been offered since 1992. The next step in technology advancement is the use of conventional, contemporary chips with improved output levels. These levels may arise from supplying greater electrical power to the chip, and must be accompanied by designs that will reduce internal chip heat to avoid permanent damage. A new LED light design uses periodic level shifting (PLS) to intermittently increase chip output levels over those of baseline. In doing so, maximal output from the chip can be achieved, but not at the risk of destroying the source. This article describes the current state of LED light units, discusses the strategy of chip design and limitations, and presents a description of an LED recently introduced that uses PLS technology.