45S5

45S5 is a type of bioactive glass, specifically a bioglass composition developed by Larry Hench. Its chemical formula is approximately 45% silicon dioxide (SiO2), 24.5% sodium oxide (Na2O), 24.5% calcium oxide (CaO), and 6% phosphorus pentoxide (P2O5). This specific composition is known for its ability to bond with both hard and soft tissues.

The key characteristic of 45S5 bioglass is its surface reactivity. When placed in contact with physiological fluids, it undergoes a series of chemical reactions. These reactions lead to the formation of a carbonate-apatite layer on its surface, which is chemically and structurally similar to the mineral component of bone. This layer acts as a scaffold, promoting the adhesion, proliferation, and differentiation of bone-forming cells (osteoblasts).

This bioactivity makes 45S5 a valuable material in various biomedical applications. It has been extensively studied and used in bone grafting and regeneration, dental implants, and as a coating for metallic implants to enhance osseointegration. Its ability to stimulate bone growth and integrate with living tissue has led to its widespread adoption in orthopedics and dentistry. Research continues to explore new applications and modifications of this versatile biomaterial.