Search results for "Load to failure"
showing 5 items of 5 documents
The impact of restorative material and ceramic thickness on CAD\CAM endocrowns
2019
Made available in DSpace on 2020-12-12T02:39:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01 Background: Endocrown restorations as a conservative approach to restore endodontically treated teeth still need an in vitro investigation under fatigue at different materials. This study evaluated the effect of restorative material and restoration thickness on the maximum fracture load of endocrowns subjected to cyclic loading. Material and Methods: Sixty (60) third molar teeth received an endocrown preparation with three different heights of remaining dental tissue (1.5, 3.0 or 4.5 mm). A leucite-based ceramic (LEU) and a lithium disilicate (LD) based ceramic were selected to manuf…
Intramedullary nailing vs. palmar locked plating for unstable dorsally comminuted distal radius fractures: A biomechanical study
2010
Abstract Background The purpose of this study was to compare the stability of a 2.4 mm palmar locking compression plate and a new intramedullary nail-plate-hybrid Targon DR for dorsally comminuted distal radius fractures. Methods An extraarticular 10 mm dorsally open wedge osteotomy was created in 8 pairs of fresh frozen human radii to simulate an AO–A3-fracture. The fractures were stabilized using one of the fixation methods. The specimens were loaded axially with 200 N and dorsal-excentrically with 80 N. 2000 cycles of dynamic loading and axial loading-to-failure were performed. Findings Axial loading revealed that intramedullary osteosynthesis (Targon DR: 369 N/mm) was significantly ( p …
Similar biomechanical properties of four tripled tendon graft models for ACL reconstruction
2021
Abstract Purpose The present study tested and compared the biomechanical properties of four different triplicate graft tendon techniques. Methods 32 tripled tendons from the common extensor muscle of bovine fingers were tested on a material testing machine, passing the end loop over a metal rod of a clevis connected to the load cell on the upper side, and fixing the lower end to a clamp. The samples were divided into four groups: (A) tripled with a free end sutured only to one of the two fixed bundles (B) tripled with a free end positioned between the two fixed strands and sutured to both (C) tripled with an S-shape and all the three strands sutured together at the upper and lower extremiti…
Periosteal repair of the dorsal calcaneocuboid ligament: a comparative biomechanical study.
2007
Background: Isolated lateral calcaneocuboid joint instability rarely is described. Missed or delayed diagnosis resulting in inadequate treatment may lead to chronic instability, followed by sports inability and handicap in daily life. Besides arthrodesis, anatomic repair augmenting the elongated dorsal calcaneocuboid ligament with a local periosteal flap has recently been described for treatment. Methods: In a controlled laboratory study, eight isolated fresh-frozen human cadaver calcaneocuboid specimens were strained in a varus direction until failure of the dorsal calcaneocuboid ligaments. Then the dorsal calcaneocuboid ligaments were reconstructed with free periosteal flaps and tensile …
Sind winkelstabile Plattensysteme mit elastischen Eigenschaften für die Stabilisierung der Oberarmkopffraktur vorteilhaft? / Eine in-vitro biomechani…
2004
AbstractWinkelstabile Platten werden mit zunehmender Häufigkeit zur Stabilisierung von Oberarmkopfbrüchen verwendet. Rigide Implantate führen bei osteoporotischen Knochenverhältnissen u. U. aber häufiger zum Versagen. Um den Effekt der Implantatelastizität zu beurteilen wurden in einer in-vitro Studie die biomechanischen Eigenschaften eines rigiden und eines elastischen winkelstabilen Plattensystems vergleichend analysiert. An 8 Humeruspaaren wurde eine instabile subkapitale Fraktur simuliert. Die Proben wurden axial- und torsions-belastet. Analysiert wurden die Steifigkeit, das Setzverhalten unter Dauerlast und die Versagensbelastung.Das elastische Plattensystem kennzeichnete sich durch ei…