Papers by Author: T. H. S. Sousa

Abstract: Non metallic materials like polyurethane has been successfully used for bone reconstruction in general and specifically in craniofacial and in mandible surgeries as an implantable material. However, any polymer alone cannot be universally successful as a medical device or structural implant because the eventual lack of well defined porous geometry, inherent interconnected porosity, the non dispensable need for a combined mechanical behavior with biological interaction and manufacturing feasibility. In this work, a bioactive material composite with high mechanical strength was designed using a castor oil polyurethane (PU) structure with a functional gradient having a dense core and a porous bioactive surface. The models and replicas for the implants were processed with Rapid Prototyping (RP) techniques and their application (case studies) were fulfilled according to the SUS (Brazilian Health Service) with the support of Santa Tereza Hospital, Petropolis, RJ.

Abstract: A material able to be used as bone implant for specific applications was developed. The proposed solution establishes that all implant surfaces should be bioactive since porous surfaces in contact with bone are extremely necessary for bone adhesion. The bioactive material composite with high mechanical strength designed with a PMMA functional structure gradient produced in this work has a dense core enveloped by a porous bioactive surface. Pore sizes and shapes as well their interconnectivity was analyzed by SEM tests; the cytotoxicity was investigated in vitro using Vero cell and bone conductivity and biocompatibility was investigated in vivo in rabbits. The implant porous bioactive part analyzed in vitro showed no toxicity and tests in vivo showed a remarkable biocompatibility and bone cell growth. Some samples with hydroxyapatite (HAp) were analyzed by EDX and SEM tests, the results showed a fair hydroxyapatite distribution in the implant pore surfaces as much as a part which was retained inside the PMMA inner porous. The average scaffold pore sizes obtained was around 250.0µm and the diameter shrinkage of 4.0% was observed in all samples. This study demonstrated that the functional gradient structure composite studied can be a good candidate for cranial bone implants due to its good bone conductivity and biocompatibility.