21,481 research outputs found
Two mosses new to the Republic of South Africa and the moss Neckera valentiniana Besch. new to the Kingdom of Lesotho
Three mosses are reported as new to countries in southern Africa: Brothera leana (Sull.) Müll.Hal., Gammiella ceylonensis (Broth. in Herzog) B.C.Tan & W.R.Buck from KwaZulu-Natal and Neckera valentiniana Besch. from Lesotho
Mineral Trioxide Aggregate Material Use in Endodontic Treatment: A Review of the Literature
Objective
The purpose of this paper was to review the composition, properties, biocompatibility, and the clinical results involving the use of mineral trioxide aggregate (MTA) materials in endodontic treatment. Methods
Electronic search of scientific papers from January 1990 to August 2006 was accomplished using PubMed and Scopus search engines (search terms: MTA, GMTA, WMTA, mineral AND trioxide AND aggregate). Results
Selected exclusion criteria resulted in 156 citations from the scientific, peer-reviewed dental literature. MTA materials are derived from a Portland cement parent compound and have been demonstrated to be biocompatible endodontic repair materials, with its biocompatible nature strongly suggested by its ability to form hydroxyappatite when exposed to physiologic solutions. With some exceptions, MTA materials provide better microleakage protection than traditional endodontic repair materials using dye, fluid filtration, and bacterial penetration leakage models. In both animal and human studies, MTA materials have been shown to have excellent potential as pulp-capping and pulpotomy medicaments but studies with long-term follow-up are limited. Preliminary studies suggested a favorable MTA material use as apical and furcation restorative materials as well as medicaments for apexogenesis and apexification treatments; however, long-term clinical studies are needed in these areas. Conclusion
MTA materials have been shown to have a biocompatible nature and have excellent potential in endodontic use. MTA materials are a refined Portland cement material and the substitution of Portland cement for MTA products is presently discouraged. Existing human studies involving MTA materials are very promising, however, insufficient randomized, double-blind clinical studies of sufficient duration exist involving MTA for all of its clinical indications. Further clinical studies are needed in these areas
Geology of Hadley Rille
The regional setting, external and internal shape, and materials of Hadley Rille near the Apollo 15 landing site are described. The petrography presented includes lithologies, regolith, talus, and outcrops. The stratigraphy exposed on the rille wall is also considered
Fault and Equity: Implied Indemnity After \u3cem\u3eHoudaille\u3c/em\u3e
This article examines the doctrine of implied indemnity in light of the recent decision of the Supreme Court of Florida in Houdaille Industries, Inc. v. Edwards. The authors discuss the meaning of fault and no fault in terms of the mechanisms of accident law, develop three models for allocating accident losses, and evaluate the change in accident law introduced in Houdaille, concluding that the court achieved conceptual consistency at the expense of equity
Serrated trailing edges for improving lift and drag characteristics of lifting surfaces
An improvement in the lift and drag characteristics of a lifting surface is achieved by attaching a serrated panel to the trailing edge of the lifting surface. The serrations may have a saw-tooth configuration, with a 60 degree included angle between adjacent serrations. The serrations may vary in shape and size over the span-wise length of the lifting surface, and may be positioned at fixed or adjustable deflections relative to the chord of the lifting surface
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