For an endodontically treated tooth not requiring a post, the requirements are for biologic width + ferrule length, (i.e. 4.5 mm of supra-bony solid tooth dentin a minimum of 1 mm thick after preparation). A tooth requiring a post needs, in addition, enough root length to allow a 4 mm apical seal and a post length apical to the crown margin, equal to the length of the crown.
It is essential to assess the functional loads to which the restored tooth would be subjected. Teeth that are endodontically treated, or are likely to be in future, should be avoided as abutments supporting precision attachment RPDs, distal extension RPDs or cantilever FPDs.
MeSH Key Words: dental prosthesis design; post and core technique; tooth, non-vital/therapy.

