What are the different types of dental fillings?

Dental fillings are commonly made from composite resin, amalgam, glass ionomer, resin-modified glass ionomer, ceramic or gold. Temporary materials and hybrid products such as compomers may also be used in selected situations. The decision is not simply about choosing a white or metal filling. Tooth position, the amount of missing tissue, chewing forces, moisture control, aesthetics, caries risk and general health all influence the final choice.

Direct answer

Fillings can be divided into two broad groups:

• Direct restorations are placed and shaped directly in the tooth during the appointment. Composite, amalgam and glass ionomer belong to this group.
• Indirect restorations are manufactured outside the mouth or produced digitally, then bonded or cemented to the tooth. Ceramic and gold inlays and onlays are examples.

No single material is ideal for every tooth. The goal is to preserve as much sound tooth structure as possible while achieving a stable, functional and maintainable restoration.

Composite resin fillings

Composite resin is often called a white filling or tooth-coloured filling. It contains a resin matrix combined with mineral filler particles. The shade can be matched to the surrounding tooth, and an adhesive system bonds the material to enamel and dentine.

Main advantages

• Natural-looking colour and finish.
• Useful for both front teeth and many back teeth.
• Can restore small fractures and worn edges.
• Adhesive bonding may allow a more conservative preparation in suitable cases.
• Localised repairs are sometimes possible without replacing the whole restoration.

Limitations

Composite placement is technique-sensitive. The tooth must usually be kept clean and dry while the adhesive and material are placed. Very large cavities, difficult moisture control or unusually heavy bite forces may make another option more predictable. Composite can also develop surface wear, marginal staining or discolouration over time. Modern materials, however, have become increasingly reliable when the case is selected and managed well.

Amalgam fillings

Dental amalgam is a metallic filling material made by combining mercury with an alloy containing metals such as silver, tin and copper. Its silver-grey appearance means it is not usually chosen when aesthetics are a priority. It has a long history of use, particularly in back teeth where durability and load resistance are important.

Potential advantages

• Good resistance to chewing forces.
• A long service history in larger posterior restorations.
• May be less sensitive than composite to some moisture-control challenges during placement.

An important safety consideration

Amalgam should be considered in the context of the individual patient. Some health authorities recommend considering non-amalgam alternatives, where appropriate, for certain groups, including people who are pregnant or planning pregnancy, breastfeeding, very young children, those with certain neurological or kidney conditions, and people with a known sensitivity to amalgam components.

An intact amalgam filling with no decay underneath is generally not removed solely as a precaution. Unnecessary replacement can remove healthy tooth tissue and temporarily increase exposure during removal. A filling may need replacement if it is fractured, leaking, associated with recurrent decay, causing a confirmed reaction or no longer functioning properly.

Glass ionomer fillings

Glass ionomer cements can chemically bond to tooth structure and release fluoride. They are often used near the gumline, on root surfaces, in paediatric dentistry, as interim restorations, as liners or bases, and in areas that do not carry very heavy chewing loads.

Advantages

• Chemical adhesion to tooth structure.
• Ability to release and recharge fluoride.
• Somewhat greater tolerance of moisture than resin composite in selected situations.
• Useful in certain high-caries-risk and paediatric cases.

Limitations

Conventional glass ionomers generally have lower fracture and wear resistance than composite or amalgam. They are therefore not always suitable for large permanent restorations in high-stress areas.

Resin-modified glass ionomer

Resin-modified glass ionomer combines the acid-base chemistry of conventional glass ionomer with resin components. It may set with light, chemical curing or both. Compared with conventional glass ionomer, it often provides better early strength and more controlled setting.

Common uses include cervical restorations near the gumline, root-surface lesions, paediatric restorations, liners and selected low-to-moderate load areas. Case selection remains important for larger restorations exposed to strong bite forces.

Compomer fillings

A compomer is a polyacid-modified composite resin designed to combine some characteristics of composite and glass ionomer. It is tooth-coloured and may release a limited amount of fluoride. It can be useful in paediatric dentistry, small cavities and selected areas where appearance matters.

Compomer should not be seen as automatically superior to both composite and glass ionomer. It is simply another material with a specific range of indications.

Ceramic fillings

Ceramic fillings are usually made as inlays or onlays. The tooth is scanned or impressed, and the restoration is produced in a laboratory or with a CAD/CAM system. An inlay sits within the cusps of the tooth, while an onlay covers one or more cusps.

Main advantages

• A colour and translucency that can closely resemble natural tooth structure.
• Good resistance to staining.
• Useful wear resistance when properly designed.
• Can restore moderate-to-large defects without necessarily covering the entire tooth like a crown.

Limitations

Ceramic restorations can cost more and may require additional planning or appointments. Although ceramics are hard and wear-resistant, they can behave in a brittle manner if they are too thin, poorly supported or exposed to unfavourable bite forces. Tooth grinding, occlusion and remaining tooth structure must be evaluated carefully.

Gold fillings

Gold inlays and onlays are indirect restorations made from high-gold-content alloys or other noble metal alloys. They can be durable, biocompatible and well suited to chewing forces. Their metallic appearance, cost and manufacturing process mean they are now selected less often than tooth-coloured materials.

The term “gold filling” may refer either to direct gold techniques or to a cast gold inlay or onlay. In routine discussion, it more commonly refers to the indirect restoration.

Temporary fillings

A temporary filling protects the tooth for a limited period until definitive treatment is completed. It may be used between root canal visits, after urgent care, while symptoms are being monitored or while an indirect restoration is being manufactured.

Temporary materials are not designed to provide the same long-term wear resistance and seal as a permanent restoration. The follow-up appointment should therefore not be delayed.

How is the right filling selected?

A dentist will usually consider:

1. Tooth position: Aesthetic demands are often greater at the front, while load resistance may dominate at the back.
2. Size of the defect: A very large cavity may need an inlay, onlay or crown rather than a direct filling.
3. Remaining tooth structure: The restoration should reduce fracture risk, not merely occupy the space.
4. Moisture control: Some adhesive materials are sensitive to saliva or blood contamination.
5. Caries risk: Fluoride-releasing materials may be useful in selected high-risk situations.
6. Bite and tooth grinding: Heavy forces affect material and design choices.
7. Aesthetic expectations: Colour, visibility and translucency matter.
8. Medical history and allergies: Known reactions to material components should be reported.
9. Cost and number of visits: Direct fillings are often completed in one visit, while indirect restorations may need a separate manufacturing stage.

Does the material alone determine how long a filling lasts?

No. Longevity is also influenced by the size and design of the restoration, quality of placement, tooth grinding, oral hygiene, sugar exposure, regular dental reviews and the location of the filling. The same material may last many years in one person and require earlier repair in another.

A filling does not remain unchanged forever. Marginal wear, cracks, recurrent decay or loss of fit may develop. A small defect does not always mean that the entire filling must be replaced; a conservative repair may sometimes preserve more tooth tissue.

When should you see a dentist?

Arrange an assessment if you notice:

• A piece of the filling or tooth has broken.
• Pain or a high contact when biting.
• Increasing sensitivity to hot or cold.
• Spontaneous pain or pain that wakes you at night.
• Food repeatedly trapping at the filling edge.
• A bad taste, swelling or discharge.
• A loose or completely lost filling.

Seek prompt dental care if swelling, fever, spreading facial pain or difficulty swallowing develops.

How Dentselfy approaches the assessment

Intraoral photos submitted to Dentselfy may help with an initial visual review of an existing filling or an obvious fracture. A photograph, however, cannot reliably show decay beneath a filling, the depth of a crack, the condition of the dental pulp or the way bite forces affect the tooth.

The final choice of material therefore requires an examination and, when needed, dental X-rays. The aim is a personalised plan that preserves sound tissue while balancing appearance, strength, maintainability and biological compatibility.

Key points

• Composite is aesthetic and versatile.
• Amalgam is durable but metallic and should be selected with individual patient factors in mind.
• Glass ionomer can release fluoride but has limitations under heavy load.
• Ceramic and gold inlays or onlays are indirect restorations requiring more planning.
• The best choice depends on the clinical needs of the tooth, not the material name alone.

Frequently asked questions

Can a white filling be used in every tooth?

It can be used in many teeth. However, a very large cavity, poor moisture control or exceptionally heavy bite forces may make another material or an indirect restoration more suitable.

Does getting a filling weaken the tooth?

A tooth already loses structure because of decay or fracture. Modern restorative care aims to preserve as much sound tissue as possible. If the loss is extensive, an onlay or crown may be needed to reduce fracture risk.

Does a stained old filling always need replacement?

No. Surface staining alone may not justify replacement. The dentist should assess marginal integrity, recurrent decay, cracks and symptoms.

Is sensitivity after a filling normal?

Mild short-term sensitivity can occur. A review is needed if it is worsening, persistent, associated with biting pain or accompanied by spontaneous pain.

Related questions

• What can I eat after a filling?
• What should I do if a filling falls out?
• Can composite fillings change colour?
• Does tooth grinding shorten filling life?
• Can a fractured filling be repaired instead of replaced?
• Can decay form underneath a filling?

Medical information notice

This article provides general information and is not a diagnosis or personalised treatment recommendation. A dentist should select the filling material after examining the tooth and, when appropriate, reviewing dental radiographs.