Issue V17N03 | Year 2020 | Editorial Fato ou Fake | Pages 62 to 67
Aft er understanding the importance of light curing units and the infl uence of their characteristics on the photoactivation, it is possible to discuss factors related to the operator’s technique that are relevant during light curing. The fi rst factor to be discussed is the distance between the light curing unit and the resin-based material to be light cured. The light beam emitt ed by light curing units is not collimated like the light beam emitt ed by lasers (light amplifi cation stimulated emission of radiation), in other words, the light beam spreads with the increase of the distance between their tip and the resin-based material. Therefore, the distance increase leads to a considerable decrease of the irradiance that reaches the restorative material.1 There is equipment that emit light beam in a more collimated way than others.2 Equipment that emit a more collimated light beam will lead to less irradiance loss with the distance increase. Studies show a 75% irradiance loss when a light curing unit that presents a less collimated light is used with a 6-mm distance from its tip to the target.