Poly-vinylphosphonic acid and metal oxide or cermet or glass ionomer cement

摘要

A glass ionomer cement composition comprises poly(vinyl phosphonic acid) dissolved in its own mass of water; and (in treble the total mass of the solution) a powder, being glass or MgO or a cermet. The powder has to be deactivated so that the setting reaction with the acid is not too fast, and this is achieved either by a raised Si:Al ratio or by heat- treating.