Definition
When the dentist speaks of “toothache under a crown”, he means pain under a previously artificially made tooth crown, e.g. under a gold crown. The toothache usually occurs suddenly and violently and is usually accompanied by throbbing and a strong sensitivity to pressure. It does not matter whether the artificial crown was made recently or was inserted years ago. These symptoms can occur at any time.
Causes
Pain under a crown is caused by a variety of factors. The most important and most frequent one is the inflammation of the tooth root. It can originate from the periodontium of the tooth or from bacteria remaining in the root canal after a root canal treatment.
A recurrence of root apex inflammation typically occurs when the body has a reduced defence system, such as in the case of a cold. The inflammation can progress rapidly and cause pus to form. The result is a painful abscess that can spread to the entire head and jaw area.
Furthermore, caries is also responsible for pain under a crown. It is called secondary caries here and often forms at the edge of the crown if the artificial crown does not fit exactly, if there is a gap or if the original caries has not been removed properly. It is diagnosed by scanning the crown margins with special instruments (hook probe).
An x-ray often does not show the desired information because the caries is overlaid by the metal or ceramic of the artificial tooth crown. With a newly made crown there is a possibility of a preparation trauma. In this case, the dental nerve was irritated by the grinding (“drilling”) to such an extent that it becomes inflamed, causing pain under the crown.
Diagnosis
A diagnosis of toothache under a crown can only be made by a dentist. After the patient interview, the examination of the aching tooth follows. First the teeth are inspected with a mirror and probe.
Especially the transition areas between natural tooth and artificial crown are thoroughly scanned with the hook probe. Soft tooth substance and gaps indicate secondary caries. The dentist then performs a sensitivity test with a cold absorbent cotton pellet.
When the patient feels the cold, it can be assumed that the tooth is still alive. If this test is negative, i.e. the cold stimulus is not registered by the patient, this may be due to the thickness of the crown material and is not necessarily an indication of a dead dental nerve. This is followed by a percussion test.
In order to find out whether the affected tooth hurts more than the surrounding teeth, they are carefully tapped with an instrument. An increased perception of pain compared to the surrounding teeth is an indication of an inflammation of the root apex. Before the dentist starts treatment, an x-ray is taken to confirm the diagnosis. If the image shows a black area around the painful tooth, it is a bone damage, which also indicates an inflammation of the root apex.
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