Bioactive glass

Bioactive glasses are a group of surface reactive glass-ceramic biomaterials and include the original bioactive glass, bioglass. The biocompatibility and bioactivity of these glasses has led them to be investigated extensively for use as implant device in the human body to repair and replace diseased or damaged bones. Bioactive glasses are a group of surface reactive glass-ceramic biomaterials and include the original bioactive glass, bioglass. The biocompatibility and bioactivity of these glasses has led them to be investigated extensively for use as implant device in the human body to repair and replace diseased or damaged bones. There is tentative evidence that bioactive glass may also be useful in long bone infections. Support from randomized controlled trials; however, is still not available as of 2015. Solid state NMR spectroscopy has been very useful in elucidating the structure of amorphous solids. Bioactive glasses have been studied by 29Si and 31P solid state MAS NMR spectroscopy. The chemical shift from MAS NMR is indicative of the type of chemical species present in the glass. The 29Si MAS NMR spectroscopy showed that Bioglass 45S5 was a Q2 type-structure with a small amount of Q3 ; i.e., silicate chains with a few crosslinks. The 31P MAS NMR revealed predominately Q0 species; i.e., PO43−; subsequent MAS NMR spectroscopy measurements have shown that Si-O-P bonds are below detectable levels There have been many variations on the original composition which was Food and Drug Administration (FDA) approved and termed Bioglass. This composition is known as 45S5. Other compositions are in the list below. The underlying mechanisms that enable bioactive glasses to act as materials for bone repair have been investigated since the first work of Hench et al. at the University of Florida. Early attention was paid to changes in the bioactive glass surface. Five inorganic reaction stages are commonly thought to occur when a bioactive glass is immersed in a physiological environment: 1) Ion exchange in which modifier cations (mostly Na+) in the glass exchange with hydronium ions in the external solution. 2) Hydrolysis in which Si-O-Si bridges are broken, forming Si-OH silanol groups, and the glass network is disrupted.