A mechanical study investigating the use of two different methods (grub and bolt screws) to secure external fixation half pins to circular frames. A four part experiment: (1) Grub and bolt screws were used to secure half pins in Taylor Spatial frames. Loosening torques were measured using a calibrated torque wrench. (2) Using universal testing machine (UTM), axial loading was applied to establi...

In this paper an optimal choice of actuator for an electric-type active mass driver (AMD) system for structural vibration control using linear quadratic controller has been developed. It is composed of an electric servomotor and a ball screw. The problems that commonly are associated with hydraulic AMD systems as noise, oil leakage, and laborintensive maintenance can be suppressed using an elec...

Introduction: Some clinicians use a handheld screw driver instead of a torque wrench to definitively tighten abutment screws. The aim of this study was to compare the removal torque of one-piece and two-piece abutments tightened with a handheld driver and a torque control ratchet. Methods: 40 ITI implants were placed in acrylic blocks and divided into 4 groups. In groups one and two, 10 ITI one...

introduction: some clinicians use a handheld screw driver instead of a torque wrench to definitively tighten abutment screws. the aim of this study was to compare the removal torque of one-piece and two-piece abutments tightened with a handheld driver and a torque control ratchet. methods: 40 iti implants were placed in acrylic blocks and divided into 4 groups. in groups one and two, 10 iti one...

Slotted and cruciate auxiliary screw head design modifications for "salvaging" a stripped hexagonal head screw were studied. Thirty screws were divided into 3 groups: Group 1 = control without modification, Group 2 = auxiliary cruciate design modification and Group 3 = auxiliary slot design modification. Screws were inserted into adhesive filled high-density synthetic bone tunnels using a hexag...

This study measured the screw joint preload of the implant-abutment interface for 7 common hex-top abutment systems. Increasingly, prosthetic designs are utilizing a direct prosthetic connection to the implant, placing the implant-abutment screw joint under direct functional loads and moments. Sufficiently high screw joint preloads are required to maintain screw joint integrity and confer clini...

BACKGROUND As one of the loads applied in implant dentistry, managing the torque is important for the success of an implant treatment. For this purpose, it is crucial to ascertain the level of torque being exerted with a hand driver. We have developed an adapter that makes it easy to measure torque by using a standard torque wrench in one's possession, rather than with a torquemeter. PROCEDUR...

BACKGROUND Although, dental implants have been a predictable option to support several types of restorations, mechanical problems are not uncommon. Retaining and abutment screw loosenings/fractures are one of the most common technical problems. AIM To present a step-by-step technique in order to remove a broken locater abutment screw fragment. MATERIALS AND METHODS A 56-year-old, edentulous...

PURPOSE This study measured the gold screw preload at the gold cylinder-abutment screw joint interface obtained by 3 torque delivery systems. MATERIALS AND METHODS Using a precalibrated, strain-gauged standard abutment as the load cell, 3 torque delivery systems tested were shown to have significant differences in gold screw preload when a gold cylinder was attached. RESULTS Mean preloads m...