The present aim of this study is to investigate the effect of different parameters influencing pounding in highway bridges. Pounding is the result of a collision between two parts of the deck and/or the deck and abutments at the separation distance during the earthquake.  In the present study, the period ratio of the adjacent frames, ground motion spatial variation, and soil-structure interacti...

Background and aims. Because of compromised angulations of implants, the abutments are sometimes prepared. The purpose of this study was to investigate the effect of removing one wall of the implant abutment on the retention of cement-retained crowns. Materials and methods. Four prefabricated abutments were attached to analogues and embedded in acrylic resin blocks. The first abutment was left ...

Experimental results on scour at abutments under unsteady clear water flow condition are presented. Three shapes of short (abutment length/upstream depth < 1) were tested, namely, rectangular/vertical wall, semi-circular, and trapezoidal/45° wing-wall embedded in uniform sands two sizes having d50 = 0.52 mm 0.712 mm. The unsteadiness the is considered form flood hydrographs three forms, name...

OBJECTIVE The aim of the present study was to analyze the soft tissue barrier formed to implant abutments made of different materials. MATERIAL AND METHODS Six Labrador dogs, about 1 year old, were used. All mandibular premolars and the first, second and third maxillary premolars were extracted. Three months later four implants (OsseoSpeed, 4.5 x 9 mm, Astra Tech Dental, Mölndal, Sweden) were...

The aim of this study was to compare titanium-reinforced ZrO(2) and pure Al(2)O(3) abutments regarding their outcome after chewing simulation and static loading. Forty-eight standard diameter implants with an external hexagon were divided into three groups of 16 implants each and restored with three different types of abutments (group A: ZrO(2) abutments with titanium inserts; group B: Al(2)O(3...

The Eads Bridge (St. Louis) and the Brooklyn Bridge (New York City) were testing grounds for caisson construction. These caissons were enormous compressed air boxes used to build riverine piers and abutments anchoring the bridges. Caisson meant faster and cheaper construction, but there was a hidden cost---caisson disease (decompression sickness). Within caissons, workers labored at pressures a...

Retention of implant-supported facial prostheses presents challenges in design that may lead to use of freestanding abutments. This is particularly so in the midface and orbit. Individual implant success rates are lower in these regions, and bone remodeling capacity may be compromised by combined modality cancer therapy. The present study was undertaken to determine the variations in load deliv...

Crack surveys of bridge decks, performed over a 10-year period in northeast Kansas as part of three studies, provide strong guidance in identifying the parameters that control cracking in these structures. The surveys involve steel girder bridges—bridges that are generally agreed to exhibit the greatest amount of cracking in the concrete decks. The surveys include monolithic decks and decks wit...

AIM The aim of this study is to evaluate through a literature review, the soft tissue response in contact with zirconia abutments, including case reports comparing prosthetics rehabilitations with zirconia and titanium abutments upto 3 years of follow-up as well as the factors that should be considered on implant's abutment selection. BACKGROUND Metallic abutments can provide grayish color wh...

BACKGROUND In cement-retained implant-supported restoration it is important to gain adequate retention of definitive restoration as well as retrievability of prosthesis. The surface of the abutment, alloy of the restoration and the type of cement used influences the retention of the restoration. There is a need to analyze the influence of surface modifications of abutments on the retentive capa...