Cavities are holes that develop in teeth and are caused by decay.
Decay around the edges of existing fillings can also lead to cavities forming, needing replacement fillings.
A cavity may cause toothache pain, especially after hot or cold food or drink.
Cavities may be identified by a dentist by examining the teeth or using dental X-rays.
Cavities can usually be treated with a filling - but if a tooth is too badly decayed, a crown or extraction may be needed.
If the decay causes the nerve or pulp of the tooth to die, a root canal will be performed. During a root canal, the centre of the tooth (including the nerve, blood vessel, and tissue) is removed along with the decayed portions of the tooth. The roots are then filled with a sealing material. If necessary, a crown can be placed over the filled tooth.