statement of the problem: the survival of pulpless teeth restored with different post and core systems is still a controversial issue. purpose: this study compared the retention of two different post and core systems and also the fracture resistance of teeth restored with these systems. material and method: eighty endodontically treated maxillary central incisors were sectioned perpendicular to...

Introduction: The restoration material commonly used as core material for pulpless posterior teeth is mostly amalgam due to its high strength and low cost and it can be used with or without pin. The aim of this study was to evaluate the influence of post material on stress distribution in mandibular second premolar tooth by finite element analysis. Method: The stress distribution was analyzed i...

statement of problem: it is yet unclear whether fiber-reinforced composite posts can enhance the mechanical properties and prevent vertical fractures of teeth under chewing loads. purpose: the purpose of this study was to compare the fracture resistance and failure mode of endodontically treated teeth restored with three different post systems. materials and methods: thirty-six maxillary canine...

Abstract:   Previous research on bracing members show that the ductility of bracing members is compromised due to the buckling phenomena. Therefore, many researchers have tried to use special considerations to increase the fracture life of bracing members. Some of these recommendations such as increasing the slenderness ratio, using lower width to thickness ratio, increasing the out-of-p...

STATEMENT OF PROBLEM Techniques and recommendations for the restoration of endodontically treated teeth have changed from the use of custom cast metal post and core system to glass fiber-reinforced (GFRC) post and composite core system. Has this latest prefabricated glass fiber reinforced post and composite core system increased the fracture resistance of teeth and reduced the incidence of unre...

Objective: The main aim of this study was to compare fracture load and fracture mode of yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) and metal-ceramic (MC) molar crowns using a modified test set-up to produce fractures similar to those seen in vivo, i.e. fractures of the veneering material rather than complete fractures. Materials and methods: 13 high-noble-alloy MC and 13 Y-TZP mo...

PURPOSE The purpose of this study was to assess the impact of the core materials, thickness and fabrication methods of veneering porcelain on prosthesis fracture in the porcelain fused to metal and the porcelain veneered zirconia. MATERIALS AND METHODS Forty nickel-chrome alloy cores and 40 zirconia cores were made. Half of each core group was 0.5 mm-in thickness and the other half was 1.0 mm...

STATEMENT OF PROBLEM Unresolved controversy exists concerning the remaining coronal tooth structure of anterior endodontically treated teeth and the best treatment option for restoring them. PURPOSE The purpose of this study was to evaluate the effect of post, core, crown type, and ferrule presence on the deformation, fracture resistance, and fracture mode of endodontically treated bovine inc...