Glass ionomer cement

Glass ionomer cement ( GIC ) is a filling material in dentistry. It is made of pure polyacrylic acid or copolymers of acrylic acid, itaconic acid or maleic acid and calcium - aluminum - silicate glass and distilled water.

Setting reaction

Acids dissolve the calcium and aluminum in the silica glass. In this case, the calcium diffuses more rapidly than the aluminum and therefore reacts first with the acid. The calcium and the acid cross-linked within the period of 5 to 10 minutes produced calcium Polycarboxylatgel. After about 24 hours, and the aluminum is deposited in the calcium Polycarboxylatgel matrix and stabilizes it so much that the water-insoluble calcium aluminum Carboxylatgel formed, which represents the actual filling material. Instead of metals, plastics may also be added. This resin-modified glass ionomer cements are cured by light (eg halogen or LED light).

Adhesion to the tooth

Glass ionomer cements hold on the carboxyl group of the acid chemically bonded to the tooth structure (enamel 5 MPa, dentine 3 MPa). An adhesive technique as plastics ( composite or compomer ) is not required. In addition, glass ionomer cements show no polymerization shrinkage. Their disadvantages compared to composite fillings are compared significantly lower fracture strength and flexural strength and the low abrasion resistance.

Indication

Glass ionomer cements are depending on the viscosity indicated for cementation of crowns and bridges, as a filling material ( sandwich technique ), as well as for milk tooth fillings and semi-permanent fillings of cavities of class I, II and V.

For smaller defects on the tooth neck caries it can be used, but then must be checked by the dentist to ensure its preservation.

In the context of sponsored by the WHO ART- supply ( " Atraumatic Restoration Treatment" = filling treatment without drills) are glass ionomer cements used as the definitive restorative material in developing countries. In areas that are not supplied with electricity and no treatment units are available, decayed teeth be treated painlessly using hand instruments and therefore do not require local anesthesia.

Special

Due to the large particle size of the silicate particles GIZ is poorly polished.

Fluoride release

With the release of fluoride ions, it prevents allegedly before the secondary caries.

Pulp compatibility

The pulp compatibility is not yet clear. There are therefore close to the pulp areas with negative fillings of calcium hydroxide cover. The cavities or crown stumps must be disinfected, as in contrast to phosphate cement, glass ionomer cement which lacks the bactericidal effect.