− This paper gives details of a round robin torque comparison involving the National Physical Laboratory (NPL) and nine other UK laboratories. The comparison covered two ranges: 20 N·m to 100 N·m and 200 N·m to 1 kN·m. The work was an effective way of disseminating the unit of torque to industry via the UK’s new national torque standard, giving assurance to laboratories and customers and identi...

ABSTRACT In order to evaluate the effect of countersinking on dental implants primary stability installed in low density bones, thirty dental implants were installed in the most proximal region of oxen ribs and grouped as follow: Group1: Fifteen implants installed by standard drilling with countersinking, Group2: Fifteen implants installed by standard drilling without countersinking. The gradua...

OBJECTIVE To evaluate the mechanical properties of the Polyaxial Advanced Locking System (PAX) in screw push-out and four-point bending. MATERIALS AND METHODS Screw push-out: PAX locking screws were applied to first generation PAX plates at three different insertion angles with two different insertion torques. A load was applied parallel to the screw axis, and screw push-out force was measure...

Headless screws are favored for internal fixation in the treatment of displaced or unstable small bone (e.g., Scaphoid) fractures, because they are embedded below the articular surface of the bone, reducing tissue irritation and immobilization. Compression plays an important role in fracture stability, maintaining gap reduction and also accelerating the healing of cancellous bone [1]. There are...

AIMS This study aims to relate bone density in Hounsfield units (Hu) with the primary implant stability measured by insertion torque (Ncm) and resonance frequency analysis (ISQ). MATERIALS AND METHODS Ten patients were included in this study. A total of 54 implant sites were provided from 10 computerized tomography scans. The computerized tomography scan was used for the preoperative evaluati...

Cancellous screws are designed to optimize fixation in metaphyseal bone environments; however, certain clinical situations may require the substitution of cortical screws for use in cancellous bone, such as anatomic constraints, fragment size, or available instrumentation. This study compares the biomechanical properties of commercially available cortical and cancellous screw designs in a synth...