Glass ionomer belongs to a group of restorative dental materials that can be used for a number of causes including dental fillings, cement, sealants and more.
Glass ionomers are a fairly new group of materials that find the use in numerous different dental procedures. They are made of silicate glass powder, ionomer, and polyacrylic acid. Once all three ingredients are put together, this initiates a reaction and the end result is glass ionomer. One of the biggest advantages of this material is that it contains fluoride that is slowly released from the structure after the placement in the mouth. There are a number of glass ionomer hybrids that are a mix between glass ionomer and other materials. They were created in order to combine the best features from the different materials. Some are the compomers which match composites and glass ionomer.
There are several types of glass ionomer, produced by many different brands. First of all, this material can be used for fillings. It has strong anti-cariogenic properties because it releases fluoride and stimulates remineralization. The indications are limited because it has a lower mechanical strength compared to composites and amalgam fillings. That’s why this material is not as indicated in the posterior region as much as the other two. They are great for the restoration of milk teeth. Another advantage of this material is the fact that it doesn’t require a completely dry surface and it can form a great retention with the surface of teeth in the presence of saliva. This makes it the perfect material when working with kids. Cavities located in the cervical areas of teeth can be hard to restore, especially when there is a significant saliva flow. This is when the glass ionomer finds a great use. It connects to the tissues with a-ionic bond, and there is no need for etching with an acid. There is a much lower rate of post-restoration sensitivity because of the good biocompatibility. The adhesion is great, and if by any chance the filling falls it doesn’t happen as a result of bad bonding between glass ionomers and the tissues. These materials can be used for a so-called “Sandwich” technique in a combination with composites. With the advanced properties of these materials today they can also be applied in the posterior regions.
The second use is a dental sealant. This is definitely one of the best materials for sealants, mostly because of the protective effect. When dentists apply sealants, they have to be sure that there is no remineralization or a cavity. The surface has to be completely clean and dry. The thing is that they actually can never know that there is no process going on with a 100% certainty. This is where glass ionomer sealants show their power. Because of the fluoride, they have the ability to stop demineralization and stimulate remineralization. It forms a tight bond with the tooth without the need for acid etching. Fluoride can also stop the growth of bacteria by affecting their metabolic functions.
Another very popular use is the one for orthodontic cement. Glass ionomers can be applied as liners, base and so much more.
One of the disadvantages are the high initial acidity and the sensitvity to moist which requires higher technical from the dentist to prevent a contamination.