AIM To evaluate the cyclic fatigue fracture resistance of engine-driven F2 ProTaper instruments under reciprocating movement. METHODOLOGY A sample of 30 NiTi ProTaper F2 instruments was used. An artificial canal was made from a stainless steel tube, allowing the instruments to rotate freely. During mechanical testing, different movement kinematics and speeds were used, which resulted in three...

Resistance to cyclic flexural fatigue failure is an important feature of rotary nickel-titanium (NiTi) instruments. The aim of this study was to evaluate the cyclic flexural fatigue failure resistance of RevoS Shaper Universal rotary NiTi files and to compare it to two other rotary NiTi files with similar size and taper, the Hero Shaper and the ProFile. Fifteen each of Revo-S Shaper Universal, ...

Repetitive lifting in the workplace has been identified to be a cause of low back disorders. Epidemiologic data further supports an hypothesis that higher repetition rate (i.e. frequency) is an added risk factor. The objective of this study was to provide experimental data testing the above hypothesis. An in vivo feline model was subjected to 20-min of cyclic lumbar loading at frequencies of 0....

BACKGROUND Single-incision anterior cruciate ligament reconstruction with a bone-patellar tendon-bone construct is commonly performed with 180 degrees rotation of the graft. It has been hypothesized that further rotation of the graft to 540 degrees can effectively shorten the graft to address graft length-tunnel mismatch. Initial biomechanical failure characteristics of rotated constructs have ...

With the inevitable selection of resistance to antimalarial drugs in treated populations, there is a need for new medicines to enter the clinic and new targets to progress through the drug discovery pipeline. In this study we set out to develop a transgenic rodent model for testing inhibitors of the Plasmodium falciparum cyclic GMP-dependent kinase in vivo. A model was needed that would allow u...

BACKGROUND The purpose of the present study was to compare the mechanical static and fatigue strength of the size 2 osteotomy plate "Activmotion" with the following five other common implants for the treatment of medial knee joint osteoarthritis: the TomoFix small stature, the TomoFix standard, the Contour Lock, the iBalance and the second generation PEEKPower. METHODS Six fourth-generation t...

PURPOSE To demonstrate a Scheimpflug-based imaging procedure for investigating the depth- and time-dependent strain response of the human cornea to inflation testing of whole eye globes. METHODS Six specimens, three of which with intact corneal epithelium, were mounted in a customized apparatus within a humidity and temperature-monitored wet chamber. Each specimen was subjected to two mechani...

OBJECTIVES This study evaluated the mechanical performance, under low-load cyclic loading, of two different knotless suture anchor designs: sutures completely internal to the anchor body (SpeedScrew) and sutures external to the anchor body and adjacent to bone (MultiFIX P). METHODS Using standard suture loops pulled in-line with the rotator cuff (approximately 60°), anchors were tested in cad...

Displacement-based seismic design and assessment procedures require as key input parameter estimates of displacement capacities of the critical elements. The displacement capacities of unreinforced masonry (URM) walls are typically determined by means of quasistatic cyclic tests. This paper shows that for URM walls failing in shear the number of applied cycles in quasi-static cyclic tests influ...

OBJECTIVES The aim of this study was to evaluate the cyclic fatigue resistance of the ProTaper Universal D1 file (Dentsply Maillefer) under continuous and adaptive motion. MATERIALS AND METHODS Forty ProTaper Universal D1 files were included in this study. The cyclic fatigue tests were performed using a dynamic cyclic fatigue testing device, which had an artificial stainless steel canal with ...