To compare the mechanical effectiveness of a new conical screw design with a conventional cylindrical screw design, the screw insertion time, torque, and pull-out strength of single-pedicle screw and triangulated-pedicle screw constructs of each type of screw were compared in human cadaveric vertebral bodies. The time required to insert the conical screws was less than that required for cylindr...

PURPOSE To assess the maximum and end torque of a fourth-generation composite humerus model with no screw inserted or with a screw inserted in the distal (subpectoral) position or proximal (suprapectoral) position. METHODS 24 large-size, fourth-generation composite humeri were randomised to the control (n=8), proximal (n=8), or distal (n=8) group. For the latter 2 groups, an 8-mm-head interfe...

A simulated lateral humeral condylar fracture was created in each of the 52 humeri collected from 26 dogs. One humerus from each pair was stabilized with a 2.0 mm cortical bone screw which was inserted in lag fashion. The other humerus from each pair was stabilized with a 2.2 mm threaded diameter Orthofix pin inserted across the condyle. Prior to each repair, an antirotational K-wire was placed...

We study the torque on low mass protoplanets on fixed circular orbits, embedded in a protoplanetary disc in the isothermal limit. We consider a wide range of surface density distributions including cases where the surface density increases smoothly outwards. We perform both linear disc response calculations and non linear numerical simulations. We consider a large range of viscosities, includin...

INTRODUCTION: In a pedicle screw fixation, the degree of osseointegration between a screw and the bone is an essential factor for the stability and fusion. In patients with osteoporosis, however, there is a high possibility for a pedicle screw loosening. Owing to this, there is a difficulty in determining the surgical indications. Previous biomechanical studies have reported that a pedicle scre...

PURPOSE To compare the effectiveness of immediate post-extractive single implants with delayed implants placed in preserved sockets after 4 months of healing. Implants that achieved an insertion torque of at least 35 Ncm were immediately non-occlusally loaded. MATERIALS AND METHODS Just after tooth extraction and in the presence of a loss of the buccal plate bone less than 4 mm, compared to t...

PURPOSE This study investigated the effect of the osteotomy diameter for implant placement torque and its effect on the osseointegration. MATERIALS AND METHODS Eight male beagle dogs received 48 implants (3.75 mm × 10 mm) in their right and left radius, 3 implants per side and allowed to heal for 3 weeks. Three experimental groups were evaluated. Group 1: implant with an undersized osteotomy ...

OBJECTIVE The aim of this study was to compare the initial stability as insertion and removal torque and the clinical applicability of novel orthodontic zirconia micro-implants made using a powder injection molding (PIM) technique with those parameters in conventional titanium micro-implants. METHODS Sixty zirconia and 60 titanium micro-implants of similar design (diameter, 1.6 mm; length, 8....