Failure Mechanisms of Fibre Posts: A Literature Review.

Abstract To review the available evidence for the causes of failure of fibre posts. A search of MEDLINE was conducted to retrieve available data on fibre posts used for restoration of endodontically treated teeth since 1980. The Cochrane Library was also separately searched for systematic reviews. Additionally, references of the retrieved articles were also hand searched for further relevant papers. All the selected papers were then critically appraised subject to meeting inclusion criteria. Nineteen prospective clinical trials were included after critical appraisal of the papers. Causes of failure of fibre posts were identified as follows: adhesive failure, root fracture, post fracture, endodontic failure, secondary caries and periodontal complications. Risk factors for each of the failures were investigated and evidence-based recommendations for minimising these complications are discussed. Although laboratory studies showed favourable mechanical and physical properties of fibre posts, clinically, there has been a wide range of failures mechanisms are reported in the literature. Adhesive failure was reported in 16 of the 19 trials, making it the most frequent cause of failure. The available evidence does not indicate a difference in short-term survival probability between metal or fibre posts. A number of risk factors, which affect the longevity of fibre posts, were identified and discussed. Since there is considerable heterogeneity in study designs and reported survival rates of included studies, longer-term well-designed standardised clinical trails are required.