An evaluation of the retentive properties of various permanent crown posts

The failure of crown posts is a frustrating experience. Explanations are given for difficulty in following the rules and for the validity of post design. The need for an additional retention is also postulated. A threaded post design is suggested to reduce the retention problem. The purely cement-retained cast post cannot comply with all the ground rules for supporting the restoration of an endodontically treated tooth. Threaded posts show a degree of success and are capable of further development. They represent progress in the correct direction.