Abstract: A self-contained light source that cures a synthetic resin coating on teeth. The self-contained light source includes an elongated container that has a central longitudinal axis and also has a proximal portion and a distal portion lying along the central longitudinal axis, an attachment that is electrically and mechanically coupled to the elongated container at the distal portion. There is an array of closely spaced light emitting diodes. Each light emitting diode emits light in the blue region of the light spectrum. A power supply is disposed within the elongated container for powering the light emitting diodes. A mount is disposed in the attachment and orients the light emitting diodes to emit parallel light. A convex lens is optically coupled to the light emitting diodes. The convex lens focuses and directs the parallel light out of the attachment in a predetermined pattern.