Polar bears (Ursus maritimus) give birth to and nurture their young in dens of ice and snow. During 1999– 2001, we measured the structure of 22 dens on the coastal plain of northern Alaska after polar bear families had evacuated their dens in the spring. During the summers of 2001 and 2002, we revisited the sites of 42 maternal and autumn exploratory dens and recorded characteristics of the und...

Bimetallic dendrimer-encapsulated nanoparticles (DENs) are important materials, because they have demonstrated improvement in performance compared to the monometallic DENs in many systems when they are used as catalysts. This tutorial review focuses on the recent research advances in bimetallic DENs with respect to their synthesis, characterization, and applications as catalysts. Bimetallic DEN...

Dens invaginatus results from an infolding of the outer surface of a tooth. The clinical importance of dens invaginatus results from the risk of pulpal disease. So, all clinicians should be aware of this anomaly. The presence of double dens invaginatus is extremely rare. This article presents three cases of double dens invaginatus in permanent maxillary lateral incisors, one with preventive res...

OBJECTIVE The purpose of this study was to assess the prevalence of dens invaginatus and to classify the types of dens invaginatus in a sample of the Turkish population. STUDY DESIGN A retrospective study was performed using periapical and panoramic radiographs of 5355 patients who presented to the Department of Oral Diagnosis and Radiology at the Ondokuz Mayis University Dentistry Faculty be...

Here we outline a new method for synthesizing fully reduced Pt dendrimer-encapsulated nanoparticles (DENs). This is achieved by first synthesizing Cu DENs of the appropriate size through sequential dendrimer loading and reduction steps, and then galvanically exchanging the zerovalent Cu DENs for Pt. The properties of Pt DENs having an average of 55, 140, and 225 atoms prepared by direct chemica...

PURPOSE To establish the mechanism of injury that causes vertical fractures of the dens. METHODS Over a 3-year period, 30 patients with dens fractures were seen at our institution. From these records, we identified and retrospectively reviewed the radiographs (n = 3), CT scans (n = 3), and MR images (n = 1) of three patients with vertical fractures of the dens to assess the characteristics of...

UNLABELLED The aim of this case report was to describe the clinical management of an unusual dens invaginatus type 3. A case of dens invaginatus in a maxillary lateral incisor with a periapical lesion is reported. The patient presented with pain and localized swelling. Despite the complex anatomy and diagnosis of dens invaginatus, non-surgical root canal treatment was performed successfully. ...

BACKGROUND AND PURPOSE Widening of the basion-dens interval is an important sign of cranioverterbral junction injury. The current literature on basion-dens interval in children is sparse and based on bony measurements with variable values. Our goal was to establish the normal values of a recently described new imaging parameter, the basion-cartilaginous dens interval in children. MATERIALS AN...