If the indirect pulp cap was unsuccessful, you may need to have additional dental work. This may include getting your tooth removed or getting a root canal. (Healthline)

When caries are in close proximity to the pulp, an indirect pulp cap can be performed. In this procedure, much of the infected and affected dentin is removed without exposing the pulp in a vital, healthy tooth. This is followed by the placement of a medicament (such as calcium hydroxide or a bioactive material) in order to promote the formation of tertiary dentin. (Spear Education)

While historically a two-step procedure, indirect pulp caps have matured into a single visit event where dentists allow a fraction of decay to remain since research suggests the alkalinity of calcium hydroxide's kills off this fraction of remaining bacteria. (Patient Connect)