Abstract: A light-curing dental tool is disclosed that can apply curing light to an in-situ dental composite from variable and controllable directions, without removal of the tool from the patient's mouth. A light guide is rotated by a mechanical or electrical mechanism actuated by the operator's hand while grasping the tool, thereby redirecting the light while remaining within the patient's mouth, and while the operator maintains visual and physical contact with the patient. Rotation speed and direction can be controllable. Light guides can be interchangeable. A fixed or rotatable light guide receptacle can be included, and can be adapted for use with pre-existing light guides. Rotation mechanisms can include gears and/or drive belts. Electrical rotation mechanisms include an electric motor, and can include switches and or buttons. The tool can be powered from an electrical outlet, or by a battery that can be recharged by docking with a base station.