G Glass-ionomer Cement was mentioned for the first time by Wilsonand Kent in 1971. From the date on, this material has been perfected andproved to be efficacious in some clinical situations, occupying anincreasingly greater space in dentistry due to the well attested adhesionpotential they offer to both enamel and dentin even on smooth andnonretentive surfaces. This adhesion is easily and quickly achieved andoffers a satisfactory sealed restoration. In this way a considerable amountof healthy tooth structure is saved as typical preparations with additionalmechanical retention become unnecessary. Because glass-ionomercements are appropiate for restoring cavities such as abrasion or erosionwhere little or no cavitiy preparation is required, these materials are verywell indicated for Class III and Class V clinical situations. Restorationsusing glass-ionomer cements now recommends to remove caries only,whilst maintaining all or as much of the surrounding healthy tooth structureas possible. Fluoride release produced by glass-ionomer cements alsoplay an important role for the restoration. In the presence of fluoride, aninitial demineralized lesion in both enamel and dentin can be successfullyremineralized and a carious lesion healed.