Glass ionomer is a type of dental material used for fillings, crowns, and other restorations. It is made from a mixture of glass particles and an acid, which allows it to bond chemically to tooth structure. This material is known for its ability to release fluoride, helping to protect teeth from decay. One of the key benefits of glass ionomer is its biocompatibility, making it safe for use in the mouth. It is also relatively easy to work with and can be used in areas where aesthetics are less critical, such as in the back teeth.