OBJECTIVETo investigate the resistance to cyclic fatigue of maxillary incisors with flared canals restored with different post-and-core materials.

METHODSThirty human maxillary central incisors were assigned randomly to two main groups (non-ferrule and 1-mm ferrule) of 15. Each main group was then divided into 3 groups of 5 specimens and restored with custom cast post-and-core (MPC), resin composite post-and-core (RCP), and resin composite core combined with prefabricated carbon fiber post (FRC), respectively. Every group was subjected to a cyclic fatigue test, and recorded the numbers of load cycles that occurred tooth fracture. All data were analyzed with two-way ANOVA and the Tukey HSD test at alpha = 0.05.

RESULTSFRC revealed significantly higher fatigue strength than the other groups (P < 0.05). Preparing a dentin ferrule increased significantly fatigue resistance (P < 0.05). The favorable (retrieval) fracture pattern of the tested specimens was discovered only in RCP.

CONCLUSIONSUsing FRC may get a long fatigue life in restoring pulpless teeth with flared canals. Dentin ferrule preparation is necessary to enhance resistance of the restorations to cyclic fatigue.

Carbon ; Chromium Alloys ; Composite Resins ; Dental Materials ; Dental Pulp Cavity ; pathology ; Humans ; Materials Testing ; Post and Core Technique ; Tooth, Nonvital ; therapy