Retrospective study of tapered, smooth post systems in place for 10 years or more.

A total of 211 consecutive patients of a restorative dentist who received full-mouth radiographs between October 1988 and March 1989 were screened for teeth treated endodontically at least 10 years earlier. In all, 51 patients had 138 teeth treated and restored by the authors. All involved teeth were restored with tapered smooth posts, cores with complete or 7/8 cast ferrules, and an onlay or cast precious metal crown (with or without veneering). No posts, splints, or bridges were loose, and only one crown was loose. There were nine failures in 138 teeth (6.5%)--three restorative, two endodontic, two root fractures, and two periodontal. When tapered smooth posts are used properly, retentive problems do not occur.