Glass ionomer dental cements: update

The performance and properties of glass ionomer cements, both conventional and resin modified, are reviewed. The setting of these materials involves an acid–base reaction, leading to the formation of a salt based matrix. In addition, resin modified glass ionomers have the complementary setting reaction of free radical polymerisation, typically of 2-hydroxyethyl methacrylate, which is added as monomer component. Both types of material have acceptable mechanical properties for application in clinical dentistry. They also bond directly to dentine and enamel, forming an ion exchange interfacial region, which confers very high durability on these restorations. Modern conventional glass ionomers have improved particle size and particle size distribution, which leads to improvements in mechanical properties. This makes them suitable for more demanding applications, including in the modern clinical techniques of atraumatic restorative treatment and minimal intervention dentistry.