GIC vs composite filling: which is better for you?

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If your dentist has suggested a GIC filling, you may wonder why it was not a composite, or whether GIC is simply a cheaper, weaker option. The honest answer is that the two materials do different jobs well. Here is how they compare, and why a dentist picks one over the other for a particular tooth.

What is a GIC filling?

GIC stands for glass ionomer cement. It is a tooth-coloured filling material made from a glass powder and an acid that react together and set in the cavity. Unlike most filling materials, it forms a chemical bond with the tooth, and it releases small amounts of fluoride over time, which can help protect the surrounding tooth from new decay. It also tolerates a little moisture while it is being placed, which matters in a child's mouth or near the gum, where keeping a tooth completely dry is difficult.

Conventional and resin-modified GIC

There are two main types. Conventional GIC sets through its own chemical reaction. Resin-modified GIC also contains some resin and is partly set with a curing light, which makes it a little stronger and quicker to finish. Your dentist chooses between them based on where the filling is going.

What is a composite filling?

Composite is a tooth-coloured mix of resin and fine glass particles. It is bonded to the tooth with an adhesive, hardened in layers with a curing light, then shaped and polished. Because it comes in many shades and polishes to a natural shine, a well-placed composite blends in closely with the rest of the tooth. It needs a dry field while it is placed, so the dentist isolates the tooth carefully. Our composite fillings page explains the appointment step by step.

GIC vs composite at a glance

When a dentist chooses GIC

Children's milk teeth

Milk teeth only need to last until the adult tooth replaces them, and a young child's mouth is hard to keep dry. GIC's chemical bond, moisture tolerance and fluoride release make it a practical choice. At our clinic, consultant paediatric dentist Dr. Vanessa Lobo often prefers GIC for baby molars. Our guide to cavities in children covers prevention as well as treatment.

Cavities at the gum line or on the root surface

Decay at the gum line, or on exposed roots in older adults, is difficult to keep dry and does not take heavy biting forces. GIC bonds well in these areas, and its fluoride helps protect a vulnerable spot.

People at high risk of new decay

For mouths that keep developing new cavities, for example with a very dry mouth, the fluoride released by GIC can be a useful extra layer of protection alongside better daily care.

As a base or a temporary filling

GIC is often placed as a protective layer under a composite in a deep cavity, or as an interim filling while a tooth is being monitored or a root canal is being completed.

When composite is the better choice

On the biting surfaces of adult back teeth, which take the most chewing force, composite usually lasts longer. It is also the standard choice for front teeth and other visible areas, where shade matching and polish matter, and for repairing chipped or worn edges. For most everyday cavities in adults, composite is the default.

How long does each last?

Lifespan depends as much on the cavity and your habits as on the material. Composite fillings commonly last many years when they are placed well and looked after. GIC usually lasts less long on surfaces that take heavy chewing, but can last well in low-stress areas such as near the gum line. Grinding, a large filling, new decay at the edges and the quality of daily cleaning all shorten a filling's life. Our guide to how long a filling lasts covers the signs that one needs replacing.

Is a GIC filling permanent?

GIC can be a long-term filling in the right place, such as a gum-line cavity or a milk tooth. It is also used as a temporary or interim filling, and on the chewing surface of an adult molar it is usually replaced or covered with a stronger material later. If you are not sure whether your GIC filling was meant to be temporary, ask at your next check-up.

Does the cost differ?

GIC is often less expensive than composite, but the material is only one part of the fee. The size of the cavity, how many surfaces are involved and how deep the decay goes usually matter more. At Prudent Dental Clinic you receive a written, itemised estimate after the tooth has been examined. Our guide to tooth filling costs in Pune explains each factor.

What about silver (amalgam) fillings?

Amalgam is the third material you may see in older fillings, though our clinic no longer places it. Our types of dental fillings guide compares all three, and our article on replacing old silver fillings explains why a sound old filling is usually best left alone.

Sources & further reading

Cochrane Oral Health (evidence reviews) · American Dental Association (MouthHealthy) · NHS, Dental Health · Indian Dental Association