objective : the aim of this study was to evaluate fracture characteristics of rigid two-tooth segments splinted with fiber reinforced composite (frc), with and without application of simulated masticatory forces. material and methods: in this experimental study, 80 extracted maxillary bicuspids were joined in pairs from the buccal aspect using frc. the specimens were divided into two groups. in...

the residual stresses in composite laminates depend on several factors including the conditions of fabricating process, property of materials, direction and lay-ups of the layers. however the thermo-elastic behavior of composite is one of the most important parameters affecting the magnitude of residual stresses. the elastic properties and residual stresses do not remain constant under cyclic t...

The current standard preparation for Class IV composite restorations is the placement of a bevel on all enamel margins. This study evaluated chamfered and beveled preparations for Class IV restorations of lesions with microfilled and macrofilled composite resin. Forty incisors were obtained and standardized lesions for Class IV restorations were formed. Twenty teeth had a 1.5-mm bevel placed an...

Characterized by their low modulus and high stretchability, soft composites have recently attracted great interest from researchers in related areas. The main objective of the present study is on the fracture property and toughening mechanism of soft composites. Two types of soft composites will be studied: soft elastic foam and the double-network (DN) composite. A theoretical/numerical study i...

OBJECTIVE To assess the influence of ormocer, nanofilled, nanoceramic, and microhybrid composite restorative systems on the fracture resistance of maxillary premolars with Class II mesio-occlusodistal (MOD) cavities. METHOD AND MATERIALS Eighty-four sound maxillary human premolars were divided into six groups of 14 teeth each. Teeth in the first group were left intact and tested as unprepared...

The purpose of this study was to determine the effect of post types and sizes on fracture resistance in immature tooth model with various restorative techniques. Bovine incisors were sectioned 8 mm above and 12 mm below the cementoenamel junction to simulate immature tooth model. To compare various postand-core restorations, canals were restored with gutta-percha and resin core, or reinforced d...

This paper describes the fracture mechanics approach behind the water pressure ‘blow-off test for characterising the failure behaviour of composite repairs on steel tubes. The technique enables the fracture toughness of the metal/composite interface to be determined at the point where failure initiates. Surprisingly the values found for the interfacial fracture toughness are typically an order ...

The effect of static and cyclic loading conditions on the stress corrosion cracking of unidirectional glass reinforced polymer (GRP) rods used in composite high voltage insulator has been investigated. A series of stress corrosion experiments have been performed on unidirectional E-glass/modified polyester composite rods. The rods have been subjected to mechanical tensile static and cyclic stre...

Excellent mechanical properties and fatigue performance of Al/Al2O3 metal-based nanocomposites caused to introduce this material as a good candidate for various applications. In this regard, the preparation and characterization of this composite can be considered as a hot issue for research. The study was carried out in several steps including: (i) preparation of Al/Al2O3 metal-based nanocompos...

This study evaluated the fracture load and failure mode of various veneer materials cemented with or without the addition of a fiber-reinforced composite (FRC) layer at the adhesive interface. Sixty intact incisors were randomly divided into three groups. Group 1 was fabricated with the heat-press technique (IPS Empress 2); Group 2 with the copy milling technique (ZirkonZahn); and Group 3 with ...