Types of Fillings for Dental Cavities

One of the greatest advantages of the technology revolution in our lifetime is the advances in medical treatments, including dentistry. While fillings for cavities continue to follow a familiar pattern of drilling and filling, the materials available today are safer and healthier to use than ever before. While amalgam fillings, what most of us refer to as "silver fillings" are still the most common, the use of gold, resin, plastic, ceramic, and ionomer fillings have become far more common than ever before.

Filling Your Cavities

To treat your cavity, your dentist will remove the decayed portion of the tooth, commonly through drilling, and then "fill" the area on the tooth where the decayed material was removed. Fillings are also used to repair cracked or broken teeth and teeth that have been worn down from misuse (such as from nail-biting or tooth grinding).

Types of Dental Fillings

Based on the location and extent of the decay, the cost of filling material, and your insurance coverage, your dentist will make a recommendation and assist you in determining the type of dental filling that is best for you.

Amalgam Fillings

Material Used: A mixture of silver, tin, zinc, copper and mercury. Mercury is nearly 50% of the mixture.
Known as: Traditional (non-bonded)
Most common use: Fillings in back teeth
Durability: At least 10 years, usually longer
Cost: The least expensive type of restorative material

Advantages of amalgam fillings

Amalgam fillings are strong. They can withstand the forces of chewing.
They are less costly than the alternatives.
Amalgam fillings can be completed in one dental visit.
They are less sensitive to moisture during the filling process than composite resin.

Disadvantages of amalgam fillings

Amalgam doesn't match the color of your teeth.
Amalgam fillings can corrode or tarnish over time. This can cause discoloration where the filling meets the tooth.
A traditional (non-bonded) amalgam filling does not bond (hold together) with your tooth.
The cavity preparation (the "pocket" in your tooth) developed by your dentist requires undercuts or ledges to keep the filling in place. Your dentist may have to remove more of the tooth to create a secure pocket.
Some people may be allergic to mercury or be concerned about its effects. Research shows that the amount of mercury exposure from fillings is similar to what people get from other sources in the environment.

Composite Resin Fillings

Material Used: A mixture of plastic and fine glass particles.
Known as: Direct and indirect. Direct fillings are placed by your dentist using a bright blue light that hardens the soft material. For indirect fillings, your dentist prepares the tooth and takes an impression of it. A laboratory or the dentist then will make the filling from the mold. During a second visit, your dentist cements this filling into place.
Most common use: Small and large fillings, especially in front teeth or the visible parts of teeth; also for inlays
Durability: At least five years
Cost: More than amalgam, but less than gold

Advantages of Composite Resin fillings

Your fillings or inlay will match the color of your teeth.
A filling can be completed in one dental visit. An inlay may require two visits.
Composite fillings can bond directly to the tooth. This makes the tooth stronger than it would be with an amalgam filling.
Less drilling is involved than with amalgam fillings. That's because your dentist does not have to shape the space as much to hold the filling securely. The bonding process holds the composite resin in the tooth.
Indirect composite fillings and inlays are heat-cured. This step increases their strength.
Composite resin can be used in combination with other materials, such as glass ionomer, to provide the benefits of both materials.

Disadvantages of Composite Resin fillings

Composite resins cost more than amalgam fillings.
Although composite resins have become stronger and more resistant to wear, it's not clear whether they last as long as amalgam fillings under the pressure of chewing.
The composite may shrink when placed, producing gaps between the tooth and the filling. This can lead to more cavities in areas where the filling is not making good contact with your tooth. The shrinkage is reduced when your dentist places this type of filling in thin layers.
These fillings take more time to place. That's because they are usually placed in layers. The increased time and labor involved also contribute to the higher cost.
Indirect fillings and inlays take at least two visits to complete if your dentist is not prepared to make the inlay while you wait. Your dentist takes impressions at the first visit and places the filling or inlay at the second visit.

Cast Gold Fillings

Material Used: Gold alloy (gold mixed with other metals)
Most common use: Inlays and onlays, crowns
Durability: At least 15 years, usually longer
Cost: More than most other materials; 6 to 10 times more expensive than amalgam

Advantages of Cast Gold fillings

Gold does not corrode.
Some people like the gold color better than the silver color of amalgam.
Gold fillings are durable enough to withstand chewing forces. They last longer than all other filling materials.

Disadvantages of Cast Gold fillings

You must visit the dentist at least twice to receive a gold filling. At the first visit, the dentist makes an impression of your tooth and places a temporary filling. The gold filling is made from the impression. It is placed at a second visit.
The cost is high because of the high cost of gold and the work involved.
If gold and amalgam fillings are right next to each other in your mouth, an electric current can result from interactions between the metals and your saliva. This can cause discomfort, called "galvanic shock."
Gold fillings are not tooth-colored.

Ceramic Fillings

Material Used: Porcelain, most commonly
Most common use: Inlays and onlays, crowns, veneers, implants, and orthodontic brackets
Durability: More than seven years
Cost: More than composite and as much as or more than gold, depending on the filling.

Advantages of Ceramic fillings

Ceramics are tooth-colored.
Ceramics are more resistant to staining and abrasion than composite resin.

Disadvantages of Ceramic fillings

Ceramics are more brittle than composite resin and can break.
A ceramic inlay or onlay needs to be large enough to prevent it from breaking. This means that the tooth must be reduced in size to make room for the extra bulk.

Glass Ionomer Fillings

Material Used: Acrylic and a component of glass called fluoroaluminosilicate
Known as: Bonded. In a traditional filling, the material sets without a bright light. Resin-modified or hybrid composite glass ionomer fillings are stronger than traditional ones. A bright blue light is used to set the material.
Most common use: Glass ionomer is used most commonly as cement for inlay fillings. It also is used for fillings in front teeth, or around the necks of your teeth, or in roots. As filling material, glass ionomer is typically used in people with a lot of decay in the part of the tooth that extends below the gum (root caries). It is also used for filling baby teeth and as a liner for other types of fillings.
Durability: Five years or more
Cost: Comparable to composite resin

Advantages of Glass Ionomer fillings

Glass ionomer matches the color of the teeth, but not always as well as composite resin. Resin-modified glass ionomer is usually a better match than traditional glass ionomer.
Glass ionomers release fluoride, which can help protect the tooth from further decay.
Glass ionomer restorations bond (stick) to the tooth. This helps to prevent leakage around the filling and further decay.

Disadvantages of Glass Ionomer fillings

Traditional glass ionomer is significantly weaker than composite resin. It is much more likely to wear or fracture.
Traditional glass ionomer does not match your tooth color as precisely as composite resin.
A resin-modified glass ionomer filling needs to be applied in thin layers. Each layer must be cured, or hardened, with a special bright blue light. Then the next layer can be added. This makes the tooth stronger, but can lengthen the time of the dental appointment.

Many thanks to SimpleStepsDental.comfor much of the above information on the types of fillings for dental cavities.

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