How long does a filling last?

Amalgam fillings have proven themselves as a material for a filling due to their durability of often 10 years and more, but are not desired due to the appearance and the ingredients.
Plastic fillings are not as durable as amalgam and must therefore be replaced at regular intervals.
Compounds and cements do not have a long shelf life, which is why they are hardly ever used (usually only in milk teeth). Cements in particular wash out quickly.
Gold or ceramic inlays are specified by the dentist with a two-year guarantee, but are usually about as durable as amalgam fillings. Well-made inlays can last for decades without anything happening to the material or the tooth.
In general, however, the longevity of filling materials is highly dependent on oral hygiene. If the dental care is poor, a filling may also become obsolete and need to be replaced more quickly than expected.

Treatment procedure of a dental filling

Placing a filling in the tooth consists of several partial steps. It depends on the size of the defect (“hole”) and which material is used. In the case of inlays, the work of the dental laboratory as well as the taking of an impression and insertion are also involved.

In principle, the first step is to drill (cavity preparation) to remove all the diseased material and to create as flat a grand layer as possible for the filling.
It may be necessary to underfill when you are near the pulp
Cavity preparation (depending on material)
Filling and curing
Shaping, polishing, control

Before a dental filling can be placed, of course, all the hard tissue destroyed and softened by caries must first be removed. Once this has been done, the cavity preparation, i.e. the shaping of the tooth cavity to receive the filling material, takes place. For a long time the saying ” extension for prevention” was considered as a guideline.

This meant that not only the carious parts were removed, but the cavity was extended to areas not yet affected, which could be susceptible to caries in the future. A lot of still healthy tooth substance fell victim to this method, so today we refrain from this method and on the contrary try to preserve as much as possible of the hard tooth substance. Drilling on a tooth that is still alive, i.e. not root canal treated, is often painful, which is why a local anaesthetic is strongly recommended in order to make the treatment comfortable for the patient and the dentist.

Every covering filling also includes an underfilling. Its function is to shield the living dental pulp from thermal and chemical stimuli. Zinc oxide phosphate cement is the preferred material for this application.

Pastes containing calcium hydroxide or zinc oxide eugenol play a lesser role. This underfilling is followed by the final supply with a top filling. For which different materials are available.

If the carious process has already destroyed the tooth to a large extent, so that a normal filling would not find a hold, retention can be created with the help of the parapulpal pins to ensure that the filling material is anchored. The small pins are screwed into the dentine and can be bent so that there is sufficient counterforce for removing forces. However, this only applies to vital (not yet root-treated) teeth.

However, this procedure involves numerous risks, such as inadvertently opening the pulp chamber or bursting the tooth along its longitudinal axis (longitudinal fracture). In the worst case, the tooth must be extracted. Therefore, a careful risk-benefit analysis should be carried out before defending oneself for the parapulpal post.

A possible alternative is underfilling. In the filling therapy we have different filling materials at our disposal depending on the needs. For the posterior region amalgam, inlay and to a limited extent composite.

For the anterior region, UV light-curing composites have established themselves. An underfilling is indispensable for every dental filling. Phosphate cement is the most commonly used material for this purpose.

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