Dental filling materials
Metal alloys (precious metal alloys and amalgam) and non-metallic materials (ceramic and plastic) are available for permanent fillings in the posterior tooth area subject to chewing stress. All other materials can currently only be classified as temporary fillings. When selecting the respective material, various aspects such as the individual dental situation, the general state of health, esthetic requirements, time and cost, etc. must be taken into account.
What side effects can occur?
The risk of the occurrence of undesirable general and local side effects is low if dental filling materials are used as intended and in the correct manner, but, as with all medicinal products, cannot be completely ruled out. Apart from rare hypersensitivity reactions (allergies), there are no scientifically substantiated findings to justify the suspicion of adverse health effects from precious metal, amalgam, plastic or ceramic restorations. Whether hypersensitive people, sick people or pregnant women react particularly to dental filling materials has not yet been clarified, but has also not been scientifically proven.
Which ingredients are associated with potential risks?
Under the stresses in the mouth, substances are continuously released in minute quantities from all filling materials.
- Gold casting alloys (inlays) contain other alloy components such as platinum, silver, palladium, iridium, copper, etc. in addition to gold in order to achieve sufficient purchase strength. To avoid undesirable effects, care must be taken to ensure that only corrosion-resistant cast metals are used.
- We know from amalgam that the mercury levels in the body – especially in the kidneys – increase with the number and size of fillings. Depending on the number of fillings and the type of diet, the average mercury intake is approximately the same as the mercury load from food and is toxicologically harmless.
- Plastics contain a large number of compounds, including formaldehyde as a reaction product, which can be released in minute quantities. Today, these resins are often used in combination with dentine adhesives, which also contain numerous active compounds. There is no evidence to date that the residual risk of general and local side effects is lower with dental resins, including the new dentin adhesives, than with amalgam.
- Ceramics may contain traces of radioactive substances and must also be used with plastics and dentin adhesives.
- Glass ionomer cements/hybrid glass ionomer cements/compomers: These materials, which have good adhesion to the tooth structure like dentin adhesives and release fluoride (against secondary caries), are only suitable for non-occlusion-supporting, definitive fillings. In addition to acids, glass ionomer cements also contain various ions such as aluminum or strontium. Hybrid glass ionomer cements and compomers also contain resin components with the potential problems mentioned above. These materials can be used as long-term temporaries and for deciduous teeth in most cases.
How long do fillings last?
Statements about the durability of a filling can only be made statistically, as in individual cases various factors influence this durability in addition to the filling material, such as the size of the filling, but also dental care. Overall, it can be assumed today that amalgam fillings and resin fillings last on average 7-8 years and glass ionomer cement fillings 1-2 years in the posterior tooth area exposed to chewing stress. Inlays made of precious metal or ceramic remain in the mouth for 10-15 years.
Which filling materials should be used?
This can only be decided on a case-by-case basis. An appropriate risk-benefit assessment is only possible if the individual situation is taken into account. In addition to knowledge about the condition of the teeth, information about general illnesses (e.g. kidney damage), allergies or pregnancy is also important. The final decision on the materials to be used can often only be made during an intervention (e.g. after removal of a defective filling or caries). Ultimately, it should be noted that none of the filling materials mentioned represent an unacceptable risk overall.
