GIC Restoration

GIC Restoration is a process, a self-adhesive restorative material. Chemically, it combines fluoro-aluminosilicate glass powder and polyacrylic acid liquid. It has a broad spectrum of restorative and pediatric dentistry uses and exhibits a potent anti-cariogenic action.

Dental Department of Shreya Hospital in Ghaziabad have expertise in GIC Restoration process. You will get the best hand for restoration of your teeth at Shreya Hospital.

Function of GIC Restoration

Glass ionomer cement is generally supplied as a powder-liquid system that is mixed manually. The powder is mainly fluoro-aluminosilicate glass, and the liquid is an aqueous solution of polyacrylic acid. Polyacrylic acid is copolymerized with carboxylic acid, maleic, tartaric, and itaconic acid to regulate the viscosity and stabilize the liquid. The liquid exhibits a thixotropic behavior: its thickness can be reversed by shaking or warming the bottle. Other supply modes include capsules, twin syringes, and single-bottle water-settable form (freeze-dried polyacrylic acid added to GIC powder).

Preparation and Restoration of the Tooth

1. Cleaning: A pumice slurry should be applied to the tooth surface using a prophy cup.
2. Conditioning of tooth: after rinsing and drying the tooth, 10% polyacrylic acid is applied for 10 seconds to increase the surface energy and wettability of the tooth, which improves chemical bonding.
3. Placement of restoration: the mixed GIC is carried to the cavity with the help of a cement carrier and adapted using a condenser. Care is necessary to avoid the cement sticking to the spatula as it is hard to remove.
4. Protection of the cement: the setting cement should be covered by a matrix band during the initial setting and by varnish, cocoa butter, or vaseline after the initial set because GIC is moisture sensitive during the first 24 hours of setting.
5. Finishing and polishing: initial finishing includes the removal of gross excess with a sharp hand instrument. Final finishing is done after 24 hours.

Mechanism of Setting GIC Restoration

The setting of GIC is through an acid-base reaction involving the following stages:

1. Dissolution and decomposition: after mixing the powder and liquid, the acid dissolves the surface of the glass particles to release SiO₄^4-, Ca²⁺, Na⁺, and F^– ions.
2. Initial setting: the Ca²⁺ released in the aqueous medium reacts with polyacrylic acid to form a three-dimensional cross-linked structure. At this time, the material has low strength, and it can be carved using sharp instruments.
3. Final setting: the setting reaction continues during the next 24 hours. During this time, SiO₄^4- forms the silica gel. The slow-moving Al³⁺ ions enter the aqueous medium and cross-link the polyacrylic acid chains, displacing the Ca²⁺ ions. This increases the final strength of the set cement.
4. Maturation: the aluminum and calcium cross-linked polyacrylate chains get hydrated over time by absorbing water from the aqueous medium. This process is known as maturation.