Fracture Resistance of Severely Damaged Incisors Restored with Different Types of Post-core Foundations

Objectives: The aim of this study was to determine the static load-bearing capacity and failure mode of incisors restored with different post-core foundations and complete crown made of conventional particulate-filler composite (PFC, G-aenial Anterior).
Methods: Forty (n = 8/group) bovine teeth were cut and made up the root length of 15 mm. They were divided into 5 main groups. Group A had teeth restored using regular-fiber post and Gradia Core as core build-up and complete crown of PFC. Group B contained teeth restored with regular-fiber post and core made of everX Flow and complete crown of PFC. In Group C, the teeth were restored with everX Flow as post-core and complete crown of PFC. Group D, post-core-crown restorations were indirectly made from CERASMART (CAD/CAM). Group E, teeth were restored with Gradia Core as post-core and complete crown of PFC. The restorations were polymerized with a hand-light curing unit. All restored teeth were stored in water at room temperature for 48 h before they were statically loaded until fracture. Failure modes were visually examined.
Results: ANOVA revealed that the restoration technique significantly affected load-bearing capacity (p<0.05). Restored incisors (Group B) had the highest load-bearing capacity (443 N) among all the groups tested. Restorations made from everX Flow post-core and PFC coverage (Group C) gave force value of 300 N, which was significantly higher than the values of Group E (p<0.05).
Conclusions: Using everX Flow as core material with regular-fiber post is promising to strengthen structurally compromised incisor teeth.