Abstract: An apparatus for applying light in selective frequency ranges to organic composite materials used in restorative dentistry for optimum curing of the composite materials includes a lamp (14) energized by power supply (12) to transmit light through a flexible light transmitting cord (22). A dichroic filter lens (18) is disposed within an end cap (32) detachably securable to the end of a contra angle probe (27) mounted on a hand held handle (28) secured to the end of cord (22) opposite lamp (14). Lens (18) is selected with reference to the particular composite material to be cured so that substantially all frequencies of light produced by lamp (14) are blocked or attenuated except the frequency range which produces uniform and complete curing of the composite material without causing radical cross-linking of the composite material.