The present invention relates to an aqueous dental glass ionomer composition comprising(A) a reactive particulate glass,(B) a water-soluble, polymerizable polymer comprising acidic groups, which is reactive with the particulate glass in a cement reaction, whereby the polymerizable polymer has a polymer backbone and hydrolysis-stable pendant groups having one or more polymerizable carbon-carbon double bonds, wherein the polymerizable polymer is obtainable by a process comprisinga) a step of copolymerizing a mixture comprising(i) a first copolymerizable monomer comprising at least one optionally protected carboxylic acid group and a first polymerizable organic moiety, and(ii) a second copolymerizable monomer comprising one or more optionally protected primary and/or secondary amino groups and a second polymerizable organic moiety,for obtaining an amino group containing copolymer；b) a step of coupling to the amino group containing copolymer a compound having a polymerizable moiety and a functional group reactive with an amino group of repeating units derived from the second copolymerizable monomer in the amino group containing copolymer obtained in the first step , wherein the optionally protected amino group is deprotected, so that polymerizable pendant groups are linked to the backbone by hydrolysis-stable linking groups,and, optionally, a step of deprotecting the protected carboxylic acid group after step a) or step b), for obtaining a polymerizable polymer；(C) a hydrolysis-stable, water-soluble monomer having one polymerizable double bond and optionally a carboxylic acid group, said monomer having a molecular weight of at most 200 Da； and(D) a polymerization initiator system.
