Microencapsulated dicyclopentadiene (DCPD) healing agent and Grubbs’ Ru catalyst are incorporated into an epoxy matrix to produce a polymer composite capable of self-healing. The fracture toughness and healing efficiency of this composite are measured using a tapered double-cantilever beam (TDCB) specimen. Both the virgin and healed fracture toughness depend strongly on the size and concentrati...

In this study, we aimed to compare the buccal and palatal cusp fracture resistance of endodontically treated primary maxillary premolars with mesial-occlusal-distal cavity which was restored with composite resin by using different types of bonding adhesives. A hundred extracted double rooted human maxillary premolars were randomly separated into five groups in which 20 teeth were included in ea...

The aim of this study is to compare the effect of various restorative materials on fracture resistance in maxillary premolars. Premolars (n = 64) with no restorations or cracks were selected. MOD cavities were prepared considering the buccolingual width to be equal to half of the intercuspal distance. The specimens were randomly divided into 8 groups, 8 specimens each: group A intact teeth, gro...

The aim of this in vitro study was performed to evaluate the effect of dentin bonding agents and glass ionomer cement beneath composite restorations and its resistance to fracture of endodontically treated teeth. Fifty sound extracted maxillary teeth were selected; ten of them for controls and the remainder were modified with root canal treatment and a mesial occlusal distal (MOD) cavity prepar...

Fracture toughness, strength, and elastic modulus of poly(methyl methacrylate) (PMMA)and poly(buty1 methacrylate) (PBMA)-impregnated alumina ceramics were measured as a function of polymer volume fraction, mean polymer particle size, and interfacial bonding between the polymer and ceramic. Fracture toughness was found to increase with increasing polymer volume fraction and decreasing polymer pa...

The marginal fracture toughness of several types of composite resins was determined by means of the rattler test. Microparticle-filled resins showed significantly higher marginal fracture toughness than conventional composites. Posterior restorative composites were intermediate between MFRs and conventional composites. Amalgams were inferior to restorative resins. These data correspond with the...

OBJECTIVES To describe a new technique, the reinforced interdental crossover composite splint (RIC), for transverse mandibular fracture repair in dogs. This technique was compared biomechanically with the established reinforced interdental Stout loop composite splint (RIS) technique. METHODS Six pairs of mandibles from young adult small breed dogs were used for the study. Osteotomies were cre...

Objectives This study aimed to evaluate the retention of composite restorations of primary anterior teeth reinforced with composite posts, glass fber posts, para-pulpal pins with composite posts, and para-pulpal pins alone. Methods Forty freshly extracted sound primary canine teeth with at least two-third of the root length remaining were selected. After disinfection, the tooth crown was cut...

The fracture behavior of a composite cylinder subjected to a moving pressure has been investigated. The resonance of stress waves can result in very high amplitude of strains in the cylinder at the instant and location of pressure front passage when the velocity of the moving pressure approaches a critical velocity. The stress wave with high magnitude, while short in duration, might not cause s...