The utilization of roots to carry post-retained crowns

A retrospective study of 5-year-old post-retained crowns made using a matched reamer/sprue technique, was carried out. Standardized radiographs enabled the length of post within the root to be compared with the maximum available length, and this was related to the success of the restoration. Six posts (11.5% of the sample) had become dislodged, of which four were successfully re-cemented. The range of root utilization varied from 46 to 137% of the calculated ideal maximum length, indicating that radiographs or measurements were not used routinely as an aid to root preparation, and in some cases the integrity of the apical seal had been severely prejudiced. Despite some very short posts, no roots had fractured. The minimum length of post which ideally should be used has been calculated as 9 mm.