The present invention relates to restorative materials, in particular to glass-ionomer cements. More particularly, the present invention relates to glass-ionomer cements having particular utility in the repair of human hard tissue, in particular as dental restorative materials and in orthopaedic surgery. We describe a composition comprising a mixture of a glass ionomer cement and zinc phosphate. Preferably, the composition comprise from 40 to 95% by weight of glass ionomer cement and from to 60% by weight of zinc phosphate. The present invention also provides a powdered composition comprising a fluorosilicate glass and deactivated zinc oxide. Such that the zinc phosphate is formed in sith by reaction between the zinc oxide and phosphoric acid.