Developing LED light curing unit prototype by combined pulse width modulation: Ouput beam irradiance

The application of high-energy light curing unit (LCU) may potentially damage dental pulp tissues due to temperature rise caused by. A previous research has displayed an output temperature of 37°C of light emitting diode - light curing unit prototype. With curing time of 20 seconds and temperature output of 37°C, the objective of this research is to optimize the irradiance of the prototype light emitting diode - light curing unit using a pulse width modulation combination method to obtain irradiance beam output of 1000 mW/cm2. The pulse width modulation mode was programmed by combining a low and high output irradiance beam into 5 modes (combinations). A high power blue LED, model Pl.02.Xl.04041, was used as a light source. Results showed that the irradiance beam output was 715±24 mW/cm2. To obtain a higher irradiance beam output of 1000 mW/cm2, a further study would be using the combination of PWM method with a higher power LED source.