Why GIC is water sensitive?

GIC is also susceptible to water loss sometime after filling; if left unprotected and exposed to the air, its surface will crack because of desiccation. Furthermore, desiccation and water contamination can continue to alter the structure of GIC for several weeks after cessation.

Is GIC water sensitive?

GIC-containing materials are technique sensitive and moisture control is mandatory for all types of GICs. Water contact at placement or at setting results in dissolution of the material. Light curing of resin-containing GICs should be done in steps when the thickness of the restoration exceeds 2 mm.

What is the role of water in GIC?

Water is an essential component of glass-ionomer cements, and has several functions in these materials [35]. It is the solvent for the dissolution of the polymeric acid, and allows it to ionise and donate protons, thereby behaving as a Bronsted-Lowry acid [35].

Is glass ionomer hydrophilic?

Glass-ionomers have certain advantages over composites as fissure sealants, specifically that they are hydrophilic and dimensionally stable. Being hydrophilic they can absorb any fluid left at the bottom of the fissure and still adhere to the enamel.

Is GIC water-based?

Being a true water-based material, GIC also is recognized as the only biological active restorative material that is currently available.

Glass ionomer cement simplified!

What are the disadvantages of glass ionomer?

Disadvantages. The main disadvantage of glass ionomer sealants or cements has been inadequate retention or simply lack of strength, toughness, and limited wear resistance. For instance, due to its poor retention rate, periodic recalls are necessary, even after 6 months, to eventually replace the lost sealant.

Why Vaseline is applied over GIC?

Similarly petroleum jelly also impedes the fluoride release, but to a very less extent. We suggest that in situations where the fluoride release property is more important than other properties it is better to coat the GIC with petroleum jelly or leave the restoration without any coating.

How does GIC release fluoride?

Fluoride release from GICs restorations following a continuous uptake process increases the fluoride concentration in saliva and in adjacent hard dental tissues. Thus, continuous small amounts of fluoride surrounding the teeth decreases demineralization of the tooth tissues.

How does GIC bond to tooth?

As a restorative material, GIC bond to the enamel and dentin via ionic and polar bonds, and the intimate molecular contact facilitates ion exchange of fluoride with the hydroxyl ions in the apatite of the surrounding enamel^5,39.

How does glass ionomer work?

Glass ionomer cements release fluoride ions at around 1 percent (above 5000 parts per million) that will effectively kill any cariogenic bacteria still present in the outer perimeter of a carious lesion. Glass ionomer cements protect the margins of a restoration from recurrent caries.

What is powder liquid ratio of GIC?

The wide variations practiced in P/L mixing ratios against the recommended ratio for restorative purpose (approximately 1:2) and that for luting purpose (~1:1 to 2:1) may affect the performance characteristics of the material.

How does GIC bond to metal?

The mechanism of bonding of glass ionomer cement involves chelation of carboxyl groups of the polyacids with the calcium in the apatite of enamel and dentin, but as in this study, metal crowns were luted to metallic dies, hence, such chemical interaction could not occur.

Is GIC a permanent filling?

GIC fillings are permanent fillings. They stay for quite a long duration (depending on your type of food intake, supari, tobacco, etc.).

Does glass ionomer need isolation?

These materials are very hydrophobic by design, and so they don't tolerate even a little bit of moisture. The isolation requirements are much more stringent during the procedure. “With glass ionomer, on the other hand, they contain water. It's a necessary ingredient for the acid-base reaction.

What is an advantage of glass ionomer restorative material?

Glass ionomer cements exhibit a number of advantages over other restorative materials. By bonding a restorative material to tooth structure, the cavity is theoretically sealed, protecting the pulp, eliminating secondary caries and preventing leakage at the margins.

Why do we apply varnish on GIC?

hence, sealing of GIC from aqueous media improves flexural strength. The cure lamp emitted heat, which may enhance the flexural strength of specimens coated with light-cured varnish.

Does GIC need bonding agent?

GICs have the inherent ability to adhere to enamel and dentine and can be placed in dental cavities with minimal preparation and without the need of a bonding agent.

Is GIC chemically bonded?

26 The chemical bonding between GIC and dental substrate involves the formation of ionic bonds between the carboxylate functional groups in the polyalkenoic acid molecules and calcium ions in the hydroxyapatite.

Why is GIC mixed with plastic spatula?

The Glass ionomer powder is powdered glass. If you use a metal spatula some of the metal will be abraded off into your mix. This will make it grey.

How long does glass ionomer release fluoride?

By means of a fluoride sensitive electrode, the fluoride release from disk-shaped specimens was determined periodically over 3 years. The glass ionomer cement released the most fluoride (1.54 +/- 4 microg/cm2 after 1 year and 248 +/- 7 microg/cm2 after 3 years).

What are the effects of exposing the GIC restoration to air or moisture?

GIC is also susceptible to water loss sometime after filling; if left unprotected and exposed to the air, its surface will crack because of desiccation. Furthermore, desiccation and water contamination can continue to alter the structure of GIC for several weeks after cessation.

How long does GIC filling last?

For conventional GIC, an initial release of up to 10 ppm and a constant long-term release of 1 to 3 ppm over 100 months was reported [70].

What is Miracle mix?

Miracle Mix is a silver alloy - glass ionomer cement developed for use as a core build-up and transitional restorative material for clinical situations where high radiopacity and a strong colour contrast is preferred.

What is GIC made of?

The main components of a GIC are glass, polyacid, water and tartaric acid. The composition of the glass can be varied widely, giving many different properties, and, to add to this, there are numerous combinations of polyacids that are suitable for copolymerization.