What distinguishes intraradicular retainers from extracoronal retainers?

Intraradicular retainers are distinct in that they are embedded within the tooth structure itself, often situated within the root canal or other internal parts of the tooth, which allows them to provide support and retention for a restorative appliance from within. This internal placement can enhance their retention because they utilize the natural tooth structure to hold them securely in place.

Extracoronal retainers, on the other hand, are positioned outside the tooth structure, meaning they do not rely on the internal anatomy for support. These retainers typically encompass the coronal portion of the tooth and are designed to hold a removable prosthesis by encircling the outer portion of the tooth.

This critical difference in placement is fundamental to understanding how each type of retainer functions in a dental restoration context. The internal positioning of intraradicular retainers provides certain advantages in cases where additional stability is needed, leveraging the integrity of the tooth structure itself.