Free Form Fabrication of Dental Copings and Restorations

DESCRIPTION (provided by applicant): The objective of this project is the development of a solid freeform fabrication system for producing dental restorations and devices. 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, there is no material waste 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. Specific Aims for Phase I: AIM 1: Modify and develop a solid free form fabrication system to "print" (fabricate) dental restorations directly. AIM 2: Determine the printing conditions to produce a dense, structurally sound part. AIM 3: Determine the correction factor required to compensate for potential shrinkage during sintering. AIM 4: Measure the accuracy and reproducibility of the printed/sintered parts. AIM 5: Analyze the microstructure and measure the mechanical and physical properties of the printed/sintered parts. AIM 6: Identify scanning and design units for integration with the solid free form printer. In the future, devices for craniofacial defects may be custom fabricated using this system. The system is capable of producing graded structures such that porosity and material properties may be designed to match specific biological or functional requirements. Although these applications may be several years away, they illustrate the novelty and power of this approach with the possibility for widespread applications in many areas of dental and medical science.