Fracture resistances of cast metal and ceramic dowel and core restorations: A pilot study

Abstract

Purpose: The purpose of this study was to compare fracture strengths of teeth restored with cast metal and ceramic dowel and cores supporting all-ceramic crowns. Materials and Methods: Eighteen recently extracted teeth were randomly divided into 3 equal groups. Metal dowel and cores (MDC) were fabricated for 1 group using a base metal alloy, and served as the control. The other groups received In-Ceram Spinell® (ICS) and IPS Empress 2® (IPS) dowel and cores. IPS Empress 1 crowns were fabricated for all samples. Each tooth was subjected to a shear force at a crosshead speed of 2 mm/min on a universal testing machine until failure occurred. Results: The mean fracture strengths and standard deviations of MDC, ICS, and IPS restorations were 1101 N (361), 832 N (288), and 1137 N (367), respectively. The differences between groups were insignificant (p < 0.05). Fractures of the all-ceramic crowns were observed in the MDC group, whereas the failure of ceramic dowel and core restorations was associated with root fracture at the cervical region. Conclusions: Due to improved mechanical properties, In-Ceram Spinell® and IPS Empress 2® ceramic dowel and cores may be candidates for the restoration of endodontically treated anterior teeth. Copyright © 2005 by The American College of Prosthodontists.