The objective of this project is the continued development of a solid freeform fabrication system for producing dental restorations and devices which began in Phase I. This system is based on the """"""""robocasting"""""""" approach. Robocasting is a solid freeform fabrication technique that uses automated extrusion of colloidal slurries, pastes, inks, etc. to build complicated structures of ceramics and metals. A great deal of investment in dental CAD/CAM has occurred in recent years due to benefits of time savings from reduction of traditional manual fabrication. In our proposed technique, as opposed to current CAD/CAM systems, material waste is minimized due to direct fabrication via printing of the desired materials. The resulting instrument will have several impressive capabilities and advantages: 1) Precise control of wall thickness and the ability to increase the thickness in portions of the restoration requiring more strength. 2) The capability for multiple materials to strategically place stronger compositions where necessary as well as graded colors leading to better aesthetic qualities. 3) The ability to fabricate a restoration from a dental scan or a dental impression. 4) Versatility, potential fabrication of removable partial denture frameworks, implant abutments and custom implants. 5) Production of blocks for existing dental CAD/CAM systems with graded color to enhance esthetics which are primarily now limited to monochromatic materials. The proposed system fulfills the aims announced in PA-04- 161, Manufacturing Processes of Medical, Dental, and Biological Technologies to develop rapid prototyping and manufacture technology. In Phase I the Aims of developing inks for printing alumina and porcelain dental materials were accomplished as well as the production of prototype multi-color blocks. The overall objective of Phase II is to have products in the form of multi color blocks, inks, and a benchtop system commercially available. Objectives for Phase II: 1. Produce a robocaster capable of fabricating multi-color blocks on a commercial scale. 2. Produce a benchtop robocaster for laboratories to fabricate crown and bridge frameworks. 3. Create user-friendly software for production of multi-color blocks and software to integrate the data obtained from a scan of dental casts for use with the benchtop robocaster. 4. Finalize the design of the multi - color block and create a shade table to allow the proper selection and positioning of a designed restoration within the block to produce the desired shade. 5. Fabricate three unit bridge frameworks using the previously developed alumina inks from Phase I and develop new inks to fabricate crown and bridge frameworks from yttria partially stabilized tetragonal zirconia. At the end of Phase II, the robcaster products will decrease fabrication time, material waste, patient treatment time and improve the reliability of the restorations. In the future, additional inks will be developed for metals and plastics to further expanding the capability of the system to cover all aspects of dental therapy.
Devices produced in this project will provide dentists and laboratories with new products for treatment of decayed and missing teeth. These products may decrease the amount of time a patient will spend at the dentist and produce a restoration that better matches the patient's teeth. There also is the potential for decreased cost by reducing material waste and additional laboratory fees.