Surface topography and defect structures associated with ballistic impact in a commercial 94 percent alumina ceramic armor are described. Fracture surfaces were examined by scanning electron microscopy, augmenting previous replication electron fractography studies. Direct transmission electron microscopy was employed in characterizing defect structures in extracted fracture fragments on replica...

AIM The aim of this report is to describe the relationship of some salivary parameters to dental erosion resulting from excessive citric acid consumption and present a description of a prosthetic approach used to restore the damaged dentition of a patient with severe erosion. BACKGROUND The high consumption of dietary sources of acids can lead to erosion or the excessive wear of dental hard t...

Background and Aim: Restoration of endodontically treated teeth is one of the most important and challenging topics in restorative dentistry. Longevity of such restorations is an essential factor in treatment planning. Amalgam build-up is a conservative method for restoration of endodontically treated teeth. Therefore, this study aimed to assess the longevity of this type of restoration in endo...

This study evaluated the masking ability of different porcelain thicknesses and combination of enamel and/or dentin porcelain layers over simulated background dental substrates with higher (A2) and lower (C4) color values. Combination of the enamel (E) and dentin (D) monolayer porcelain disks with different thicknesses (0.5 mm, 0.8 mm, and 1 mm) resulted in the following bilayer groups (n=10): ...

background and aims. use of porcelain as inlays, laminates and metal-ceramic and all-ceramic crowns is common in modern dentistry. the high cost of ceramic restorations, time limitations and difficulty of removing these restorations result in delays in replacing fractured restorations; therefore, their repair is indicated. the aim of the present study was to compare the shear bond strengths of ...

STATEMENT OF THE PROBLEM The literature is limited on the detailed description of the practice of Irish general dentists in the provision of crowns. PURPOSE OF THE STUDY To review the provision of crowns by dentists in Ireland and identify opportunities for improving current clinical practices. MATERIALS AND METHODS A questionnaire was posted to 500 general dentists selected randomly from t...

PURPOSE The aim of this clinical retrospective study was to evaluate the clinical quality, success rate, and estimated survival rate of anterior veneers made of silicate glass-ceramic in a long-term analysis of up to 20 years. MATERIALS AND METHODS Anterior teeth in the maxillae and mandibles of 84 patients (38 men, 46 women) were restored with 318 porcelain veneer restorations between 1987 a...

Background and aims. Use of porcelain as inlays, laminates and metal-ceramic and all-ceramic crowns is common in modern dentistry. The high cost of ceramic restorations, time limitations and difficulty of removing these restorations result in delays in replacing fractured restorations; therefore, their repair is indicated. The aim of the present study was to compare the shear bond strengths of ...

In sheet metal forming processes with complex strain paths, a part is subjected to large plastic deformation. This severe plastic deformation leads to high plastic strain localization zones and subsequent accumulation of those strains. Then internal and superficial micro-defects and in other words ductile damage is created. This damage causes quality problems such as fracture. Therefore, design...

Homogeneous global wrinkling patterns such as labyrinths, herringbones, ripples and straight stripes can be widely observed in natural and artificial systems, but localized wrinkling patterns (not including buckle-driven delaminations, folds, ridges and creases) are seldom observed in experiments. Here we report on the spontaneous formation of highly ordered wrinkled stripes localized by cracks...