What is an amalgam filling?

Commonly known as a “silver filling” or “black filling”, amalgam has been used in dentistry for more than 150 years. A powdered silver-tin-copper alloy is mixed with liquid mercury; the mixture hardens quickly and the mercury becomes bound within the alloy.

Amalgam was favoured for a long time because of its durability, ease of placement and tolerance of a moist environment. However, it has drawbacks: it does not bond to the tooth, so more tooth structure must be removed for retention, and it is not aesthetic. Because of environmental mercury pollution, its use has been reduced in many countries under the Minamata Convention, and the European Union has largely ended the placement of new amalgam fillings as of 2025. This decision does not mean that existing fillings in your mouth must be removed; it is primarily an environmental regulation.

Is the mercury in amalgam dangerous to health?

Very small amounts of mercury vapour can be released from set amalgam during chewing and with hot drinks. According to operative dentistry sources, this amount has not been linked to any known health harm for people in the general population who have amalgam fillings. The defined signs of chronic mercury poisoning (such as tremor, fatigue, insomnia and kidney involvement) are not the same as certain complaints (for example headaches) that are said to “go away” after amalgam removal.

That said, a confirmed allergy to mercury can occur in rare cases; changes called lichenoid lesions may then appear in the oral tissues next to the filling. If this is the case, replacement has a genuine medical justification. In addition, many countries recommend avoiding new amalgam fillings in pregnant women, breastfeeding mothers and young children as a precaution.

When should an amalgam filling be replaced?

Whether a filling needs replacing is decided by its condition, not its age. During the examination the dentist assesses the filling visually and, if needed, with magnification and X-rays.

Keep in mind that every removal takes away some healthy tooth structure along with the filling, and the cavity becomes larger. Unnecessary repeated replacements can eventually leave a tooth needing a crown. That is why the modern approach is to repair and monitor whenever possible.

How are old fillings assessed during an examination?

The answer to “Is my filling worn out?” comes from interpreting several findings together:

• Marginal fit: The dentist checks for gaps, steps or chipping where the filling meets the tooth. Small notches can form at amalgam margins over time; not every one of them means decay.
• Discolouration: A grey shadow around the filling is often just the metal showing through. Brown, soft tissue, on the other hand, suggests decay. Sometimes the two cannot be told apart by visual examination alone.
• X-rays: Especially helpful for showing decay under fillings on the surfaces between teeth.
• Crack check: Teeth with large amalgam fillings can develop fine crack lines in their walls; these are assessed with methods such as a bite test and transillumination.
• Patient complaints: Symptoms such as sensitivity, food trapping or pain on biting guide the assessment.

When these findings are considered together, a decision is made whether to monitor, repair or completely renew the filling.

How is an amalgam filling removed?

When amalgam is drilled out, the heat generated by the bur can melt a phase of the filling and release mercury vapour. Removal should therefore be carried out with measures that protect both the patient and the dental team:

• Rubber dam: Isolates the tooth from the rest of the mouth, reducing the swallowing and inhalation of particles.
• High-volume suction: Vapour and particles are removed at the source.
• Plenty of water cooling: Reduces heating and the vapour it produces.
• Sectioning the filling: Removing the filling in large pieces rather than grinding it away completely reduces heat and dust.
• Waste management: Amalgam waste is not thrown in ordinary rubbish; it is collected separately.

After removal, any decay is cleaned out, the remaining tooth structure is assessed and a suitable restoration is chosen. The depth of the cavity, the thickness of the remaining tooth walls and how much biting force the tooth receives directly influence which material is selected. In deep cavities, areas close to the nerve may be covered with a protective liner. When several fillings need replacing, treatment is usually grouped by half of a jaw and split into several sessions with the patient’s comfort in mind — something international patients visiting Istanbul can plan around their stay.

What replaces amalgam?

• Composite filling: A tooth-coloured, resin-based material that bonds to the tooth. Frequently chosen for small and medium-sized cavities.
• Inlay / onlay: If the cavity is wide and the cusps are weakened, restorations made outside the mouth (from ceramic or composite) can support the tooth better.
• Crown: A crown may be needed if the tooth is badly broken down or cracked.
• Glass ionomer: Used in some special situations, particularly on root surfaces and for temporary solutions.

What are the risks?

• Loss of tooth structure and enlargement of the cavity during removal
• Temporary sensitivity in deep cavities; rarely, involvement of the nerve and the need for root canal treatment
• Previously unnoticed cracks being revealed
• The new filling also needing maintenance over time

These risks explain why replacement should only be done when it is truly necessary.

Frequently asked questions

Related pages

Medically reviewed by: Dr. Dt. Mehmet Fuat BozabaSpecialist in periodontology · September 2026

Appointments and information: Message us on WhatsApp or call +90 544 289 66 33. Yayla Dental Akademi, Bahçelievler / Istanbul.

Sources: Roberson TM, Heymann HO, Swift EJ (eds.). Sturdevant’s Art and Science of Operative Dentistry, 4th edition. Mosby, 2002; Rai B, Kaur J. Fundamentals of Operative Dentistry. Jaypee Brothers Medical Publishers, 2010; Pitts NB (ed.). Detection, Assessment, Diagnosis and Monitoring of Caries. Monographs in Oral Science, Vol. 21. Karger, 2009.

This article is for information only; diagnosis and treatment plans are determined by a dentist after an examination.