| 0578 Material Evaluation for a Novel Dental Implant Design | ||
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J.R. PIASCIK1, J.Y. THOMPSON1, and D. MCDEVITT2, 1University of North Carolina, Chapel Hill, USA, 2Incumed Incorporated, Raleigh, NC, USA Objective: To investigate a novel dental implant design that utilizes a biocompatible polymer sheath. This design incorporates technology found in orthopedic implants used for sports medicine injuries. For dental applications, a polymer sheath would be screwed into prepared bone and an implant would be threaded into the sheath. An interference fit between the sheath and implant creates radial expansion of the sheath, firmly securing the implant. Using this configuration might allow immediate loading of an implant with functional stresses. The modulated stresses applied could promote rate-enhanced remodeling of bone, reducing load transmission at the bone/implant junction, and preventing micro-cracking of cortical and cancellous layers. To determine if this type of configuration is viable for dental applications necessitates evaluation of mechanical and biological characteristics. One requirement is selection of a sheath material that displays sufficient fatigue resistance to survive high-cycle loading seen in vivo. This study evaluated two medical grade polymers (High-Density Polyethylene, DOW HDPE-08454N; Polypropylene, Sunoco Chemical F-040-F). Methods: The fatigue testing fixture, incorporating a high modulus polyetherimide block designed to affix the implant at a 30° angle from the crosshead axis, was configured to comply with the ISO-14801 standard. Polymer sheaths were injection molded and threaded into the fixture, then an implant (Ti-6Al-4V) was threaded into the sheath. Each sample was cyclically loaded (20-225N, MTS Evolution) in an environmental chamber (buffered saline, 37°C) for 1 million cycles at 2Hz. Failure criteria was based on development of crazes and/or cracks. Results: High-density polyethylene displayed multiple crazes throughout the threaded portion of the sheath, as well as some cracking around the upper rim. Polypropylene survived the test with negligible craze and/or crack development, and displayed minimal cyclic plastic strain. Conclusion: The polypropylene material evaluated is more suitable for this type of dental application. Support provided by Incumed Incorporated, Raleigh, NC, USA. | ||
| Seq #78 - Composition, Physical Properties, and Fatigue 10:15 AM-11:30 AM, Thursday, 11 March 2004 Hawaii Convention Center Exhibit Hall 1-2 | ||
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Back to the Dental Materials: VI - Polymer Materials-Mechanical Properties and Degradation Program
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