Glass Ionomer Filling

The glass ionomer is one of the materials used in the field of dentistry as a filling material. This binding material is also known as dental cement. The glass ionomer finds application in the luting process. It is commonly used in restoration and repair of teeth. The glass ionomer filling was first introduced for dental care in the year 1972. Chemical bonding takes place between dental hard tissues and this material. The release of fluoride also makes it durable.

Facts about Glass Ionomer Filling

The materials used in making the glass ionomer filling are fluoroaluminosilicate and acrylic. Both powder and liquid forms of this material are available.

Glass Ionomer Liquid
The liquid form of glass ionomer was earlier available in the form of aqueous solution. Nowadays, this liquid is available in the co-polymers. These co-polymers are available with maleic, itaconic and tricarboxylic acids. The disadvantage of using the aqueous solutions was that these were highly viscous. Over time, these liquids used to gel. The gelation tendency and viscosity of today's glass ionomer liquids is less due to the presence of these acids; the reactivity of liquids too is greater.

Powder of Glass Ionomer
The powder form of glass ionomer is chemically composed of calcium fluoroaluminosilicate glass. The aluminosilicate proportion in powder form of glass ionomer is high and therefore, the reactivity too is greater. The fluoride present in this chemical also is useful since, it plays the role of ceramic flux. The additives like zinc oxide, barium, strontium and lanthanum are responsible for radiopacity. The raw materials used in the preparation of glass ionomer are heated at a temperature ranging from 1100 °C to 1500 °C.

A large cavity in teeth requires to be filled with some kind of sealant/filling material. The glass ionomers prove to be useful for the purpose of such fillings. If the cavity is big enough (i.e. it reaches below the gum line) the material proves to be especially helpful. These fillings can also be used for the front teeth. Neck of the teeth which doesn't play any role in the process of biting/chewing is filled with glass ionomer.

Advantages
The benefits of using glass ionomer sealants are enlisted below:

• The procedure of using glass ionomer cement doesn't require any kind of prior preparation.
• It is the most suitable material to be used as filling for teeth. This is because, the color of teeth matches with that of the filling.
• There are less chances of occurrence of problems like tooth decay and leaking. Firm bonding of this filling material with the teeth is the reason why these problems do not occur.
• The glass ionomer filling apart from binding firmly to the teeth also helps to maintain the dental health. This is because fluoride is released by this material over time.
• This material shrinks very less in comparison to other sealants.

Limitations
Here are the disadvantages/limitations of using the glass ionomer cement.

• No matter how closely the color of this filling material resembles that of teeth, one can mark out the difference without much difficulty.
• The alternative filling materials to glass ionomer are much stronger. Glass ionomer undergoes wear and tear quite easily.
• The glass ionomer filling activity doesn't require much preparation. However, the treatment procedure itself is a lengthy one. Each and every layer of this filling has to be bonded separately; the time required for the whole process is therefore, greater.
• Sensitivity to water can be observed during the setting phase.
• The other limitations like abrasive nature, brittleness and solubility make it prone to damage.

This glass ionomer filling is very useful owing to the benefits being offered. However, you should also understand the advantages and limitation of using this material.