The field of orthodontia has been witnessing numerous reforms in terms treatment modalities through the years, under which concept absolute anchorage employing mini-implants can be well subsumed. usage orthodontic bone screws witnessed growing popularity and deemed to revitalize management complex malocclusions. Orthodontic are larger diameter (2 mm) comparison with average mini-implant placed ...

Study Design Mechanical study. Purpose To compare the pullout strength of different screw designs and augmentation techniques in an osteoporotic bone model. Overview of Literature Adequate bone screw pullout strength is a common problem among osteoporotic patients. Various screw designs and augmentation techniques have been developed to improve the biomechanical characteristics of the bone-...

The ability of various screw types to stabilize depressed tibial plateau fractures was determined in a biomechanical study using a Sawbones model. Two sizes of both cancellous and cortical screws were evaluated for both supportfrom below and through the depressed fragment. As a general trend, cancellous bone screws provided a greater resistance to fragment displacement than cortical bone screws...

The purpose was to investigate whether a new biphasic and injectable ceramic bone substitute Cerament™ that rapidly remodels to bone, may contribute to the retention of titanium implant screws during the healing period, and to analyze the pattern of bone formation around titanium implants.Titanium screws were implanted in rat tibiae and embedded with or without Cerament™ on the cortical surface...

BACKGROUND The objective of this study was to investigate the biomechanical effects of medial fracture gap augmentation in locked plating of an unstable 2-part proximal humeral fracture with calcar screws and insertion of a corticocancellous bone block. Furthermore the mechanical behavior of dynamic locking screws in the non-parallel arrangement of a proximal humeral plate was of interest. ME...

OBJECTIVE To determine elution characteristics of bone morphogenetic protein (BMP)-2 from a polycaprolactone coating applied to orthopedic implants and determine effects of this coating on osseointegration. ANIMALS 6 sheep. PROCEDURES An in vitro study was conducted to determine BMP-2 elution from polycaprolactone-coated implants. An in vivo study was conducted to determine the effects on o...

BACKGROUND This study was designed to derive the theoretical formulae to predict the pullout strength of pedicle screws with an inconstant outer and/or inner diameter distribution (conical screws). For the transpedicular fixation, one of the failure modes is the screw loosening from the vertebral bone. Hence, various kinds of pedicle screws have been evaluated to measure the pullout strength us...

BACKGROUND When performing arthroscopic ankle arthrodesis for end-stage ankle arthritis, internal fixation is performed using bone screws after appropriate preparation. However, optimal characteristics of bone screws have not been examined in terms of pressure force. Objective comparisons of bone-screw performance may provide information on procedures for arthroscopic ankle arthrodesis. The stu...

Study Design Biomechanical study of pedicle screw fixation in osteoporotic bone. Objective To investigate whether it is better to tap or not tap osteoporotic bone prior to placing a cement-augmented pedicle screw. Methods Initially, we evaluated load to failure of screws placed in cancellous bone blocks with or without prior tapping as well as after varying the depths of tapping prior to screw ...

In this study, we prepared nano-hydroxyapatite/polyamide 66/glass fibre (n-HA/PA66/GF) bioactive bone screws. The microstructure, morphology and coating of the screws were characterised, and the adhesion, proliferation and viability of MC3T3-E1 cells on n-HA/PA66/GF scaffolds were determined using scanning electron microscope, CCK-8 assays and cellular immunofluorescence analysis. The results c...