Once the structure of a tooth has been damaged by decay, there is no way to repair it.
However, if decay is picked up at an early stage its progression can be blocked.
Decayed material can be removed, and replaced with a restorative material generally a tooth coloured filling.
If the decay is more extensive, then another option is a crown. The decayed or weakened area is removed and repaired and a covering jacket – the crown – is fitted over the remainder of the tooth.
If the nerve in a tooth has died, either from decay or a blow, then a dentist will consider root canal treatment.
This involves removing the centre of the tooth, including the nerve and blood vessel tissue.
The root is then filled with a sealing material, and the process is completed with either a filling, and possibly a crown.