Often glass, which is made traditionally by quenching a melt, is considered a homogenous solid by its users. This has been true certainly in the biomedical field, where, for example, the most widely used 45S5 sodium calcium phosphosilicate glass is assumed to be a single phase bioactive material. However, now we are learning that it is not only phase separated at nanoscale, but in fact living cells recognize the nanoheterogeneity and respond accordingly; their response is significantly affected by the nature of phase-separated nanostructure. It was also discovered that more than ten thousand times larger cells respond differently on nano-macro porous calcium silicate bioactive scaffolds that differ only in the size of nanopores, for example, 4nm vs 18nm. These observations demonstrate the importance of nanostructure for the performance of glass products in dental and bone regeneration applications.
