Restoring endodontically treated teeth with posts and cores--a review.

Objective: The prognosis of endodontically treated teeth depends not only on the success of the endodontic treatment, but also on the type of reconstruction. These considerations include the decision of whether or not to use posts.

Methods And Materials: A literature review has been performed to create guidelines for the reconstruction of endodontically treated teeth by posts and cores.

Results: Posts should only be used for the retention of core material in cases where little dental substance remains, ie, one or no cavity walls. A ferrule of 2 mm has to be provided, by surgical means if necessary. The post length is limited by the necessary apical seal of 4 to 6 mm. In cases of short posts, adhesive fixation is preferred. Ceramic posts show a higher risk of fracture than fiber posts which are retrievable. Composites have proven to be a good core material. Posts should be inserted if endodontically treated teeth are used as abutments for removable partial dentures.

Conclusion: These guidelines are based mainly on in vitro studies with an evidence level of II a or II b, as there is a lack of randomized clinical studies available. The remaining tooth structure is an important factor influencing the indication of posts and cores, yet it is not sufficiently recognized in clinical studies and in vitro. Therefore, further prospective clinical studies are needed.