Apexification can be defined as a procedure used to treat a specific root canal problem.
The root canal system is the natural cavity within the center of the tooth that contains the dental pulp and extends from the crown of the tooth to the end of the root (the apex). Teeth always have at least one root, and each root always has at least one root canal.
The root canals of most teeth are tapered from the crown to the root end, and can be treated with conventional methods. However, some teeth have an opening at the bottom of the root canal that has not closed, called an open apex. It is most commonly found in teeth that are not fully developed (usually in children) but can also be found in mature teeth whose roots have eroded. Apexification is a treatment used to create a calcified/solid barrier (the recalcification) at the tooth root’s open apex.