Influence of Root Posts and Retained Coronal Dentin on Fracture Resistance and Failure Pattern of Endodontically Treated Maxillary Incisors

Abstract

Background: The contribution of cast metal and prefabricated fiber posts and that of retained coronal dentin to fracture resistance and failure pattern of endodontically treated maxillary incisors was evaluated.

Materials and Methods: Sixty extracted maxillary incisors were endodontically treated, prepared with full shoulder, and divided into six groups of 10 each. A 2 mm high axial circumferential wall of coronal dentin was left in teeth of three groups, but removed in teeth of the other groups. Post space was prepared in 40 teeth: 20 of them received cast gold posts (10 with axial ring and 10 without) and likewise the other 20 teeth received quartz fiber posts. A 2 x 3 mmwell was prepared as core foundation in the remaining 20 teeth. All teeth were restored with metal crowns. Tooth fracture strength was measured in compression at 135 to its long axis until failure. Data were analyzed by analysis of variance and Tukeys tests. Mode of failure data were analyzed using Chi-square test.

Results: Root posts had no significant influence on the fracture resistance (P > 0.01). Metal posts caused root fractures whereas failures of fiber post restored teeth were predominantly reparable.

Conclusions: Root posts did not enhance fracture resistance of endodontically treated maxillary incisors. Tooth resistance to fracture was made up by the ferrule effect afforded by the bracing of full crown against the retained coronal structures.




doi: http://dx.doi.org/10.4021/jcs204e