Post systems are used in the restoration of endodontically treated teeth where there has been significant loss of the clinical crown. A post provides a method to secure filing material to the tooth.  The aim of this trial was to  assess the survival rate of two different post systems after 5 years of service.

Patients were randomised to receive long glass fibre-reinforced posts or long metal screw posts. Survival was assessed at 5 years (mean follow up  61.37 months).  The time and type of complications prior to this recall was noted. Statistical analysis was performed using the log-rank test and Kaplan-Meier analysis. Additionally, a Cox regression was performed to analyze risk factors.

They found that

• survival rate of fibre-reinforced posts was 71.8%.
• survival rate  of metal screw post group was significantly lower, 50.0% (log-rank test, P = .026).
• Metal posts resulted more often in more unfavourable complications (eg, root fractures); consequently, more teeth (n = 17) had to be extracted.
• The Cox regression identified the following risk factors:
• position of the tooth (anterior vs posterior teeth),
• degree of coronal tooth destruction, and the post system (fibre-reinforced post vs metal screw post).
• Fibre-reinforced restorations loosened in several patients; in some of these cases (n = 6), patients did not notice this, leading to the extraction of teeth.

The authors concluded

Long metal screw posts should be used with great care in endodontically treated teeth. Besides the selection of the post system, other factors influence the survival of the restoration.

Schmitter M, Hamadi K, Rammelsberg P. Survival of two post systems–five-year results of a randomized clinical trial. Quintessence Int. 2011 Nov-Dec;42(10):843-50. PubMed PMID: 22025998.

* Note that the available abstract does not provide any information on lost to follow or whether there was only one restoration per patient.

Related review

A Cochrane review of  post systems  by Bolla et al was published in 2007. The primary aim of that review was to compare the clinical failure rate of different types of posts used for the restoration of endodontically-treated teeth.

Bolla M, Muller-Bolla M, Borg C, Lupi-Pegurier L, Laplanche O, Leforestier E. Root canal posts for the restoration of root filled teeth. Cochrane Database of Systematic Reviews 2007, Issue 1. Art. No.: CD004623. DOI: 10.1002/14651858.CD004623.pub2.