Risk factors of post-and-core restorations – Clinical results after 5 years

Objective: Glass fibre reinforced composite posts (GFP) are considered to have favourable mechanical properties for the reconstruction of endodontically treated teeth (ETT). The aim of the investigation was to evaluate the survival of two tapered and one parallel-sided GFP system in teeth with different stages of hard tissue loss and to identify risk factors for restoration failure. Methods: 149 GFRP in 111 patients (age: 53.9±14.4 yr; male: 45 [40.5%]; female: 66 [59.5%]) were followed for 5 to 79 months (mean±SD: 50±21 months). GFPs were adhesively luted and the core was built with a composite resin. Cox proportional hazards models were used to evaluate the association of clinical variables and failure rate. Results: After exclusion of endodontic failures significantly higher failure rates were found for restorations of anterior teeth compared to posterior teeth (HR: 3.8; 95% CI: 1.5-9.7; p=0.005) and for restorations in teeth with no proximal contacts compared to at least one proximal contact (HR: 3.1; 1.0-9.5; p=0.043). A boarder line significance for teeth restored with single crowns compared to fixed bridges (HR: 3.9; 1.0-9.5; p=0.05) was observed. Conclusion: The tooth type and presence of adjacent teeth were found to be significant predictors of failure rates in ETT restored with GFP.