Abstract: An articulator, for use in making dentures or parts thereof. It has an upper principal member and a lower principal member. An upper support is provided for holding a maxillary cast fixedly mounted on the side of the upper member facing the lower principal member. A lower support holds a mandibular cast. This support is mounted on the lower principal member and faces the upper principal member. The lower support has a releasing/locking arrangement making it possible for an operator to move the lower support freely in several directions when the arrangement is in its released mode and to lock it in a desired position requiring only a slight holding in place of the casts in relation to each other by the operator during a locking procedure.

Abstract: A motor driven dental instrument for peeling away a layer of a tooth is provided. The rotational movement of the driving shaft is transformed into an axially oscillating, not rotatable movement of a tool support of a working tool. The working tool is able to be placed in an angular position in relation to the tool support chosen by the dentist.

Abstract: An apparatus for making holograms of an object is described. The apparatus has a laser source emitting a collimated or slightly divergent laser beam, and a holder for a holographic plate to hold the holographic plate between said object and said laser source in a position near said object. A positive lens means having its focus is placed between said lens means and said holographic plate such that a divergent laser beam is impinging on said holographic plate and cover an illuminating area on said plate extending well beyond the area of said object in a plane parallel to said holographic plate. A closed housing is placed around said laser source and said lens means, which housing has a controllable shutter to be opened only at control provided in an end wall in a position cutting the beam path of said outgoing laser beam.

Abstract: A dental instrument is described by which a tooth file is automatically driven by a driver for producing alternating movement forces in the axial direction of a tool support bearing the file to a predetermined axial limit position in each direction, the distance between these limit positions being such that the instrument tool support is able to take an axial position in which it is unaffected by those movement forces. The movement forces affect the tool support only when it is moved from the unaffected axial position by an external force exerted on it and then by only the one of the forces acting in the axial direction opposite to the external force. External forces in each direction are able to move the tool support up to a predetermined maximum amplitude of action.