A glass ionomer cement (GIC) is a dental restorative material used in dentistry for filling teeth and luting cements. These materials are based on the reaction of silicate glass powder and polyalkenoic acid. These tooth-coloured materials were introduced in 1972 for use as restorative materials for anterior teeth (particularly for eroded areas, Class III and V cavities). As they bond chemically to dental hard tissues and release fluoride for a relatively long period, modern day applications of GICs have expanded. The desirable properties of glass ionomer cements make them useful materials in the restoration of carious lesions in low-stress areas such as smooth-surface and small anterior proximal cavities in primary teeth. Results from clinical studies do not support the use of conventional or metal-reinforced glass ionomer restorations in primary molars, due to higher occlusal stress loads. However, use of glass ionomers in molar teeth is common as cementing, luting or basing materials may be used in temporary to intermediate term restorations in children and adults, particularly in difficult and dentally compromised cases and for medically compromised and elderly patients.