Effect of residual coronal structure on the resistance of teeth restored with posts

Objectives: To compare the fracture resistance and failure patterns of endodontically treated teeth with a progressively reduced number of residual walls restored using composites and posts. Materials and methods: After endodontic treatment, 90 premolars were divided as follows: group 1: 4 walls; group 2: 3 walls; group 3: 2 walls; group 4: 1 wall; group 5: 0 walls. Groups 2 to 5 were divided into subgroups, without and with posts. Fracture tests and statistical analyses were performed. Results: The following loads were recorded: 5a > 5b > 4b > 3b > 1 > 4a > 2b > 3a > 2a. Conclusions: The samples restored with fiber posts exhibited predominantly restorable fractures. The number of residual walls influenced the fracture resistance.