Silicon Nitride as a Biomedical Material: An Overview

Silicon nitride possesses a variety of excellent properties that can be specifically designed and manufactured for different medical applications. On the one hand, silicon nitride is known to have good mechanical properties, such as high strength and fracture toughness. On the other hand, the uniqueness of the osteogenic/antibacterial dualism of silicon nitride makes it a favorable bioceramic for implants. The surface of silicon nitride can simultaneously inhibit the proliferation of bacteria while supporting the physiological activities of eukaryotic cells and promoting the healing of bone tissue. There are hardly any biomaterials that possess all these properties concurrently. Although silicon nitride has been intensively studied as a biomedical material for years, there is a paucity of comprehensive data on its properties and medical applications. To provide a comprehensive understanding of this potential cornerstone material of the medical field, this review presents scientific and technical data on silicon nitride, including its mechanical properties, osteogenic behavior, and antibacterial capabilities. In addition, this paper highlights the current and potential medical use of silicon nitride and explains the bottlenecks that need to be addressed, as well as possible solutions.