Abstract: One or more of feed systems for printers, printers and methods for building a three-dimensional product are provided. A feed chamber of the feed system stores a particulate material, and a deposition chamber receives the particulate material stored by the feed chamber. A heater is in thermal communication with a heating region of the deposition chamber to convert the particulate material into a gel. A nozzle provided to the deposition chamber emits the gel in a pattern to build the three-dimensional product. A conveyance system transports the particulate material towards the heating region and expels the gel from the deposition chamber through the nozzle according to instructions of a control system. An ultraviolet light source such as one or more ultraviolet LEDs can be arranged adjacent to the nozzle to cure the deposited gel using ultraviolet light.

Abstract: A teeth whitening system includes a head unit adapted to be worn on a user's head, a light housing supported by the head unit proximate to the user's mouth, the light housing including a light source, and a mouth piece including a tray portion adapted to surround the user's teeth. At least one of the light housing or the mouth piece includes a receptacle, and the other of the light housing or the mouth piece includes a plug portion adapted to engage in the receptacle. The present application also provides an apparatus for whitening teeth, a mouth piece for use in whitening teeth, and a method of whitening teeth.