Development of Novel Processing Methods for Producing Bone Augmentation and Replacement Materials and Devices

摘要

Trauma to the head can result in the loss of teeth, injury to the ear and fracture of the jaw and/or cranium. The ability to produce materials and/or devices that can be used easily and effectively in the treatment of maxillofacial trauma is greatly needed. In addition, the ability to combine therapeutic agents with the restorative materials may greatly enhance the healing process or reduce the possibility of subsequent infection. Near net shape forming (NNSF) is a unique method for producing ceramic components which have high strength in the green state. Therefore, the aim of this proposal is to investigate the use of near net shape forming as a potential method for quickly fabricating both temporary and permanent maxillofacial restorative materials and/or devices possessing a wide range of physical characteristics. To meet these objectives, two types of non-toxic, thermally and chemically activated, gellable binders were investigated. Thermally activated gels become rigid when heated or cooled to a temperature that activates gelation. Chemically activated gels cross-link in the presence of various cations. Binders investigated include chitosan, xantham gum, locust bean gum and carageenan. These were mixed with either hydroxyapatite or tricalcium phosphate powders and the resulting composites were evaluated for chemical, biological, and mechanical properties. Formulations were produced that enable the composites to be injected through a syringe. Results indicate that composite mechanical properties are controlled by the amount of powder present, and the morphology of the crystals in the powder. Additionally, results indicate the it is possible to produce material that is porous, can release therapeutic agents to the would site, and are biodegradable. Unfortunately, the initial in vivo work indicated that the binders can cause a localized inflammatory response and may not be suitable.