most previous laboratory studies of local scour at bridge abutments were performed in rectangular channels in which the distributions of flow velocity and bed shear stress were considered uniform in the transverse direction. in reality however, bridge abutments are usually located in the floodplain zone of rivers where velocity and shear stress distributions are directly affected by the lat...

Scour is one of the main causes hydraulic structural failures. The present experimental study examines use riprap, submerged vanes, and a combination these for scour reduction around vertical walls spill-through abutments under clear-water conditions. Specifically, influence placing riprap stones with different apron shapes (geometry) and/or group vanes constant height length on abutment was ex...

OBJECTIVES The effect of inter-implant distance on retention and resistance of implant-tissue-supported overdentures is lacking in the literature. An in vitro study was performed to evaluate this effect for mandibular implant-tissue-supported overdentures retained by two ball attachments. MATERIALS AND METHODS An acrylic cast of an edentulous mandible was fabricated. Three pairs of implants w...

The aim of this study was to evaluate the effect of unilateral misfit at different levels on a crown-implantretention screw system of implant-supported crowns. Hexagon castable UCLA abutments were cast in Co-Cr alloy to fabricate 48 metallic crowns divided into four groups (n = 12). Group A: crowns did not present misfit; Groups B, C and D: crowns were fabricated with unilateral misfit of 50, 1...

Mr. P is a 69-year-old male who presents with a chief complaint of, “I have neglected my teeth for 20 years and I’d like to have them fixed.” He is a lifelong nonsmoker, in good health, with no known drug allergies and no significant past medical history. Dental findings are notable for significant edentulousness: teeth numbers 1, 2, 3, 5, 7, 10, 13, 16, 17, 18, 19, 20, 30, 31, 32 are not prese...

Excessive heat generation at the implant-bone interface may cause irreversible bone damage and loss of osseointegration. The effect of heat generation in vitro at the implant surface caused by abutment reduction with medium- and extra-fine-grain diamond and tungsten burs in a high-speed dental turbine was examined. Titanium-alloy abutments connected to a titanium-alloy cylindrical implant embed...

background and aims. in contrast to prepared natural dentin abutments, little is known concerning factors influencing the retention of fixed prostheses cemented to implant abutments. the aim of this study was to investigate the effect of implant abutment height on the retention of single castings cemented to wide and narrow platform implant abutments. materials and methods. thirty-six parallel-...

PURPOSE The objectives of this case series are to describe a novel clinical approach to treat completely edentulous patients and determine its viability. Computer-guided implant planning was used to create a screw-retained surgical template (ST) supported by transitional implants and a fixed screw-retained provisional prosthesis supported by the transitional implants at the time of definitive i...

BACKGROUND There is limited evidence for the outcome of short implants (7 mm) to rehabilitate posterior jaws. PURPOSE To report on the outcome of 7 mm short implants in the rehabilitation of posterior areas of atrophic jaws 1 year after loading. MATERIALS AND METHODS This prospective study included 127 patients treated with 217 implants supporting 165 fixed prostheses. Final abutments were ...