Short answer: An amalgam filling is a gray filling material that is about half mercury. Replacement is recommended if there is decay underneath, a fracture in the filling, breakdown at the edges or an allergy; removing intact fillings simply because they contain mercury is generally not considered necessary. Removal is carried out with precautions such as a rubber dam, high-volume suction, plenty of water cooling and sectioning the filling into pieces. It is most often replaced with a composite filling or an inlay/onlay.
Many people who have gray-silver fillings placed years ago wonder whether these fillings are harmful and whether they should be replaced. The decision about amalgam filling removal can swing between extremes, from unnecessarily removing a healthy, intact filling to neglecting a filling that is genuinely problematic. In this article we explain, in a measured way and in light of current information, what an amalgam filling is, when replacement is recommended, how removal is done safely and which materials can be used instead.
What is an amalgam filling?
An amalgam filling is a gray-silver filling material, not tooth-colored, made by mixing liquid mercury with a powdered alloy of metals such as silver, tin and copper. By weight it is about half mercury. After mixing, it hardens quickly and forms a structure that withstands chewing forces.
Because of its durability and ease of use, amalgam was for many years one of the most widely used filling materials, especially in the back teeth. Today, however, its use has declined considerably because of the development of tooth-colored materials, rising aesthetic expectations and the environmental effects of mercury. Under the international Minamata Convention, many countries have decided to phase down the use of amalgam; the European Union banned the use of amalgam in dental treatment from 2025, with limited exceptions.
Hardened amalgam in the mouth can release very small amounts of mercury vapor; this amount can increase somewhat during chewing, teeth clenching or drinking very hot beverages. Health authorities state that there is not enough evidence that existing, intact amalgam fillings pose a health risk to the general population. Even so, for certain risk groups, alternative materials are recommended when a new filling is placed.
When should an amalgam filling be replaced?
An amalgam filling should be replaced when new decay forms underneath it or at its edges, when there is a fracture or crack in the filling or the tooth, when the edges of the filling break down, or when the person has a documented allergy to amalgam. Removing an intact amalgam filling that fits well at the edges and causes no complaints, simply because of the mercury it contains, is generally not recommended.
The main situations that may require replacement are:
- Secondary decay: Bacteria leaking in at the edges of the filling and causing new decay underneath.
- Fracture or crack: A crack forming in the amalgam itself or in the tooth walls around the filling; large amalgam fillings can, over time, set the stage for the tooth to fracture.
- Edge breakdown: Loss of fit between the filling and the tooth, formation of a ledge or food getting trapped.
- Allergy or tissue reaction: Although rare, some people may develop whitish lesions called lichenoid lesions on the inner cheek or tongue where they touch the filling.
- Aesthetic preference: A person may want dark fillings in visible areas replaced with a tooth-colored material. In this case, the dentist explains the pros and cons of the procedure in detail, including the loss of healthy tooth structure.
Pregnancy and breastfeeding are periods when removal can temporarily increase exposure to mercury vapor. For this reason, unless there is an urgent need, amalgam removal is usually postponed during these periods.
How is a safe amalgam removal protocol carried out?
Safe amalgam removal is done with a series of precautions to minimize the inhalation or swallowing of mercury vapor and particles that may be released during the procedure by the patient, the dentist and the surroundings. These precautions matter because heating the amalgam as it is cut with a bur increases vapor release.
- Rubber dam: The tooth being treated is isolated from the rest of the mouth with a thin rubber sheet. This prevents amalgam particles from being swallowed or coming into contact with the oral tissues.
- High-volume suction: A high-powered suction device is used right next to the tooth to remove vapor and particles at the source.
- Plenty of water cooling: Plenty of water is used during cutting to reduce heating of the amalgam and vapor formation.
- Removal in sections: Instead of grinding the filling completely into powder, it is divided into a few pieces and removed in chunks. This method reduces both vapor formation and the length of the procedure.
- Protective equipment: Eye protection and suitable masks are used for the patient, the dentist and the assistant; the patient's face and body are protected with a cover.
- Ventilation: Good ventilation of the treatment room and, when needed, the use of air filtration systems are preferred.
- Waste management: Removed amalgam pieces and waste are collected in line with regulations using special separators and waste containers so that they do not enter the environment.
If several fillings are to be replaced, the procedures are usually planned across several appointments rather than squeezed into one session. This decision depends on the number and size of the fillings and the condition of the teeth.
What filling replaces amalgam?
Depending on the size of the cavity left after amalgam removal and the remaining tooth structure, options such as a composite filling, glass ionomer, a ceramic or composite inlay/onlay, or a crown for more extensive loss can be used.
- Composite filling: A tooth-colored, resin-based material bonded to the tooth. It is the most commonly chosen option for small and medium-sized cavities and allows less healthy tooth structure to be removed than amalgam.
- Glass ionomer: A material that can release fluoride. It can be used in areas with little chewing load, in cavities at the gumline or as a temporary solution.
- Inlays and onlays: When removing a large amalgam filling leaves a loss that includes the cusps of the tooth, ceramic or composite pieces made in a laboratory or with a digital system are bonded to the tooth. They can better support the remaining walls of the tooth.
- Crown: When most of the tooth has been lost or cracks are deep, the whole tooth can be covered and protected.
If decay under the filling turns out to be deep or close to the nerve during removal, a protective base material may be applied before the filling, or, rarely, root canal treatment may be needed. The pros and cons of the options are discussed in detail during the examination.
What are the most common questions about amalgam fillings?
The most frequently asked questions about amalgam fillings concern their safety and whether they all need to be removed at the same time. The short answers can be summarized as follows:
Are amalgam fillings harmful?
There is not enough scientific evidence that intact amalgam fillings cause health problems in the general population. Nevertheless, for groups such as pregnant women, breastfeeding mothers, young children, people with impaired kidney function and those allergic to mercury, alternative materials are preferred when new fillings are placed.
Should I have all my amalgam fillings removed?
Removing all intact, problem-free fillings is generally not recommended. This is because every removal also costs some healthy tooth structure, and mercury exposure can temporarily increase during the procedure. The decision should be made by assessing each filling individually.
Will I feel anything after removal?
After the new filling, there may be sensitivity to cold and heat for a few days. This sensitivity usually eases on its own; if it lasts a long time or there is pain when biting, let your dentist know. You can find other answers about fillings and treatments on our frequently asked questions page.
When should you have your amalgam fillings assessed?
If you notice darkening around an old filling, sensitivity when chewing, a fracture in the filling or a ledge you can feel with your tongue, it is a good idea to book a checkup to assess the condition of your filling. At our polyclinic in Oran, Çankaya, fillings are examined one by one with a clinical examination and X-rays; whether replacement is needed, which material would be suitable if so and the precautions to be taken during removal are explained in detail in advance.
Frequently asked questions
How many years does an amalgam filling last?
Amalgam fillings are durable materials and can often stay in the mouth for many years. The lifespan of a filling varies with its size, the tooth it is in, chewing forces and oral hygiene. Regular checkups make it possible to catch edge breakdown early.
Can amalgam fillings be removed during pregnancy?
Because removal can temporarily increase exposure to mercury vapor, amalgam removal is usually postponed during pregnancy and breastfeeding unless there is an emergency. If there is a condition requiring treatment, such as pain or infection, the dentist determines the appropriate approach.
Is a composite filling that replaces amalgam durable?
Today's composite materials have been developed to withstand chewing forces in the back teeth as well. For very large cavities, options such as an inlay, onlay or crown can protect the tooth better. The right choice depends on the size of the cavity.
Is mercury swallowed during amalgam removal?
Precautions such as a rubber dam, high-volume suction and plenty of water cooling are used to minimize swallowing of amalgam particles and inhalation of vapor during the procedure. Removing the filling in sections also reduces exposure.
