BACKGROUND: The favorable properties of silicon nitride (Si3N4) ceramic, such as high stability and biocompatibility suggest its biomedical use as an implant material. The aim of this study was to test its suitability for osteosynthesis. MATERIALS AND METHODS: A Si3N4 prototype minifixation system was manufactured and implanted for osteosynthesis of artificial frontal bone defects in three minipigs. After 3 months, histological sections, CT and MRI scans were obtained. Finite element modeling (FEM) was used to simulate stresses and strains on Si3N4 miniplates and screws to calculate survival probabilities. RESULTS: Si3N4 miniplates and screws showed satisfactory intraoperative workability. There was no implant loss, displacement or fracture. Bone healing was complete in all animals and formation of new bone was observed in direct contact to the implants. CONCLUSIONS: Si3N4 ceramic showed a good biocompatibility outcome both in vitro and in vivo. This ceramic may serve as biomaterial for osteosynthesis, e.g. of the midface including reconstruction of the floor of the orbit and the skull base. Advantages compared to titanium are no risk of implantation to bone with mucosal attachment, no need for explantation, no interference with radiological imaging.
BACKGROUND: The favorable properties of silicon nitride (Si3N4) ceramic, such as high stability and biocompatibility suggest its biomedical use as an implant material. The aim of this study was to test its suitability for osteosynthesis. MATERIALS AND METHODS: A Si3N4 prototype minifixation system was manufactured and implanted for osteosynthesis of artificial frontal bone defects in three minipigs. After 3 months, histological sections, CT and MRI scans were obtained. Finite element modeling (FEM) was used to simulate stresses and strains on Si3N4 miniplates and screws to calculate survival probabilities. RESULTS:Si3N4 miniplates and screws showed satisfactory intraoperative workability. There was no implant loss, displacement or fracture. Bone healing was complete in all animals and formation of new bone was observed in direct contact to the implants. CONCLUSIONS:Si3N4 ceramic showed a good biocompatibility outcome both in vitro and in vivo. This ceramic may serve as biomaterial for osteosynthesis, e.g. of the midface including reconstruction of the floor of the orbit and the skull base. Advantages compared to titanium are no risk of implantation to bone with mucosal attachment, no need for explantation, no interference with radiological imaging.