Glass ionomer cements are popular today because they satisfy many of the characteristics of an ideal cement. They can be mixed easily by hand or triturator. They bond to teeth moderately, have optimum flow properties allowing easy seating, are cariostatic and are relatively inexpensive. On the downside, however, they are not easy to use properly, can cause significant postoperative tooth sensitivity, are moderately soluble in mouth fluids and have slightly less than optimum strength characteristics. Resin modifications of glass ionomer cements, to be introduced soon, may overcome many of the negatives associated with current glass ionomer cement. There will be further discussion of these as soon as they are available.