a method and apparatus for curing dental material with radiation from a halogen lamp provides for a shifting of a spectrum of the radiation to a shorter wavelength for increased rate of curing by adjusting current flow within a heating element of the lamp . the current is applied over an interval of time for accomplishing the curing . feedback and feedforward circuitry , operative with a control signal of a regulated power source to reduce voltage applied by the power source to the heating element during an initial portion of the interval of time , prior to obtaining an operating temperature of the heating element , to maintain an upper bound on the magnitude of the current applied to the heating element , thereby to the vivid unnecessary and operations of the heating element for increased operating lifetime of the lamp .