Apparatus for making a dental prosthesis or pattern therefor

An apparatus for making a prosthesis from a two-sided work piece, including

• a milling machine having a cutting tool terminating at a cutting tip that has at a predetermined start position an exact spatial relationship with respect to a working reference plane of the milling machine,
• a holder for the work piece that in one positions presents one side of the work piece to the cutting tool and in an inverted position presents the other side of the work piece to the cutting tool,
• said milling machine and holder having interactive elements that enable the holder to be repeatedly inserted, removed and inverted, and then reinserted into the milling machine at the same predetermined start position with each insertion, or reinsertion after inverting, and
• a drive mechanism for the milling machine that is initially operated when the work piece is in the first position to partially cut through one side of the work piece to drill away a substantial portion of material from the work piece while avoiding penetrating through the work piece with the tip of the cutting tool to form in the work piece a cavity having a surface part corresponding to at least a portion of the prosthesis being made,
• said drive mechanism returning the cutting tool to the start position after partially cutting through said one side of the work piece to enable filling the cavity at least partially with a support material,
• said drive mechanism adapted to be operated to completely cut through the opposite side of the work piece after filling the cavity to finish making a prosthesis having a surface essentially free of defects.

An apparatus comprising

• means for holding a two-sided work piece from which is milled a dental prosthesis,
• a milling machine having a cutting tool terminating at a cutting tip that has at a start position an exact spatial relationship with respect to a working reference plane of the milling machine,
• said milling machine and holding means including interactive elements that enable the holding means to be repeatedly inserted, removed and inverted, and then reinserted into the milling machine at a predetermined location with each insertion, or reinsertion after inverting,
• said holding means in a first position presenting one side of the work piece to the cutting tool and in an inverted position presenting the other side of the work piece to the cutting tool,
• said milling machine with the work piece is in the first position being operated to partially cut through one side of the work piece to drill away a portion of material from the work piece while avoiding penetrating through the work piece with the tip of the cutting tool to form in the work piece a cavity having a surface part corresponding to at least a portion of the prosthesis being made, enabling the work piece to be inverted after filling the cavity at least partially with a support material to present to the cutting tool a second side of the work piece, and
• means for positioning the cutting tool to overlie the second side of the work piece that is opposite a surface part corresponding to at least a portion of the prosthesis being made, and
• means for operating the cutting tool to completely cut through the second side of the work piece to form a prosthesis that is supported within the work piece by the support material.