Performance of Post-retained Single Crowns: A Systematic Review of Related Risk Factors

Numerous factors may influence the survival/success of post-retained restorations of endodontically treated teeth (ETT). The aim of this review was to assess the influence of the number of remaining coronal walls, the use or disuse of posts, and their type on the clinical performance of these restorations.

Randomized controlled trials and controlled clinical trials for ETT restored with a combination of post/crown or no post/crown were searched for in MEDLINE, Embase, and the Cochrane Library. Two authors independently reviewed all identified titles and abstracts for eligibility. Tables were generated to summarize the included studies, and reports of randomized trials were assessed for bias using the Cochrane risk of bias tool.

Nine articles were identified as meeting the inclusion criteria. Teeth without ferrule presented the highest values of variation of success/survival (0%-97%), whereas teeth with remaining coronal walls (1, 2, 3, or 4 walls with ferrule) presented lower variation. The use of posts with a high elastic modulus success/survival ranged between 71.8% and 100%, whereas posts with a low elastic modulus ranged between 28.5% and 100%. The survival of crowns without posts varied between 0% and 100%. The poor performance of posts with a low elastic modulus and without posts was associated with the absence of ferrule and the preservation of only 1 coronal wall.

The restoration of ETT should focus on the maintenance of the coronal structure. Until more studies with longer follow-up periods are available, posts with a high elastic modulus appear to present with better performance when restoring ETT with no ferrule.