Objectives The main goal of this study was to evaluate the fracture resistance of maxillary second premolar teeth with standard and conservative mesio-occluso-distal (MOD) cavity designs. Methods Sixty maxillary second premolars were randomly divided into 6 Groups of 10 teeth. G1 consisted of intact teeth. G2 was prepared with separated proximal boxes that were designed to be 1 mm approximate...

Aim To evaluate the fracture resistance of simulated immature teeth with an apical plug of biodentine followed by composite resin vs total obturation with biodentine tested immediately and after 3 months of aging and also to find out the chemical composition of dentin in contact with these materials. Materials and methods Extracted human maxillary central incisors with simulated immature apex...

PURPOSE This study compared the fracture resistance and color stability of two commercially available, preveneered stainless-steel crowns before and after four sterilization techniques. METHODS Thirty-five crowns from each of two manufacturers were divided into five groups. Four groups were sterilized twice using one of the following techniques: steam autoclave at both 121 degrees C (15 PSI) ...

Akin to other mineralized tissues, human cortical bone can resist deformation and fracture due to the nature of its hierarchical structure, which spans the molecular to macroscopic length scales. Deformation at the smallest scales, mainly through the composite action of the mineral and collagen, contributes to bone’s strength or intrinsic fracture resistance, while crack-tip shielding mechanism...

Objective. To assess fracture resistance and failure mode of repaired fiber-reinforced composite (FRC) cusp-replacing restorations. Methods. Sixteen extracted human premolars with fractured cusp-replacing woven (Group (A)) or unidirectional (Group (B)) FRC restorations from a previous loading experiment were repaired with resin composite and loaded to fracture. Results. Differences in fracture ...

Maleic anhydride-modified polypropylene was compounded with commercially available surface-modified montmorillonite in a twin-screw extruder. Recompounding ensured the removal of visible tactoids from the extrudate but TEM and XRD techniques showed nonuniform dispersion of clay platelets. In this study, we investigated the mechanical and fracture properties of nanoclayfilled polypropylene. Emph...

Mineralized tissues, such as bone and tooth dentin, serve as structural materials in the human body and, as such, have evolved to resist fracture. In assessing their quantitative fracture resistance or toughness, it is important to distinguish between intrinsic toughening mechanisms, which function ahead of the crack tip, such as plasticity in metals, and extrinsic mechanisms, which function pr...

This study evaluated the influence of alveolar bone level on the fracture resistance of root restored with post and core. Forty-eight extracted human mandibular premolars were divided into six groups. Cast posts and cores were cemented (MN8 and MP8) or resin cores were built up with fiber posts and composite resin (FN8, FP8, FN4, and FP4). Post length was 8 mm (MN8, MP8, FN8, and FP8) or 4 mm (...

AIM The aim of the present study was to evaluate the effect of the use of composite fibers (glass fiber and polyethylene fiber) at the gingival third of mesio-occlusodistal (MOD) cavities on the fracture resistance of endodontically treated premolars. MATERIALS AND METHODS A total of 45 extracted premolars underwent endodontic treatment. MOD cavities, 2.5 ± 0.2 mm thick at the buccal and ling...

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...