Effect of Distance on Irradiance and Beam Homogeneity from 4 Light-Emitting Diode Curing Units
By Dr, Richard Price
At the distances examined, ICB varied significantly among the 4 curing lights tested. The curing lights also differed significantly in terms of beam homogeneity, as characterized by top hat factors. The top hat factors were similar for the Fusion and Demi curing lights at all distances, but were lower for the Bluephase 16i and lowest for the FlashLite Magna. At a distance of 8.0 mm, the useful beam diameter for the Bluephase 16i unit was less than 4 mm (2.60 ± 0.08 mm) and significantly lower than that of the Fusion and Demi curing lights. Finally, curing lights delivering a high irradiance exceeding 1000 mW/cm2 at their emitting tip may not adequately cure resins at the bottom of the proximal box of a deep Class II cavity preparation unless the light curing time is extended.
These results indicate that deep restorations may not be adequately cured if the curing time is based on data obtained when the curing light is positioned close to the radiometer or resin. In addition, a single irradiance value reported by a dental radiometer cannot describe the light output from a curing light.