re-preparation with rotary or reciprocating files and passive ultrasonic irrigation (PUI). Twenty maxillary molars were prepared using ProTaper instruments up to F1. The teeth were filled with AH Plus and ProTaper gutta-percha points using the single-cone technique. Thereafter, the specimens were scanned using a micro-computed tomography system (Micro-CT #1). Then, the root canal filling was re...

Intimal hyperplasia (IH) is the first cause of failure of an arteriovenous fistula (AVF). The aim of the present study was to investigate the effects on endothelial cells (ECs) of shear stress waveforms derived from AVF areas prone to develop IH. We used a cone-and-plate device to obtain real-time control of shear stress acting on EC cultures. We exposed human umbilical vein ECs for 48 h to dif...

BACKGROUND In endodontic therapy, continuous rotary instrumentation reduced debris compared to reciprocal instrumentation, which might affect the incidence of post-endodontic pain (PP). The aim of our study was to assess whether PP incidence and levels were influenced by the choice of rotary or reciprocal instruments. METHODS In this meta-analysis the Pubmed and EM databases were searched for...

Objective: The purpose of this study was to compare the apically extruded debris during endodontic retreatment of teeth with open apices using hand instruments and rotary instruments with continuous rotation and reciprocation. Methodology: Forty-five single-rooted maxillary incisors and canines were used. The root tips were dissected and #1 Gates Glidden burs were allowed to protrude 1 mm beyon...

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...

Reciprocating tachycardia in a patient with a leftsided atrioventricular accessory pathway (AP) (Kent bundle, type A) capable only of ventriculo-atrial (V-A) transmission is described. The V-A AP is established as an essential link of the tachycardia circuit, as evidenced by : 1) retrograde atrial activation of the left atrium (LA) 60 msec or more before the low and high right atrium during rec...

The purpose of this study was to evaluate the presence of dentinal defects after root canal preparation with hand instruments and two different reciprocating instruments. Sixty freshly extracted mandibular incisor teeth were selected for this in vitro study. On the basis of root length, mesiodistal and buccolingual dimensions, the teeth were allocated into three identical experimental groups (n...

Paraplegic users of mechanical walking orthoses, e.g. advanced reciprocating gait orthosis (ARGO), often face high energy expenditure and extreme upper body loading during locomotion. We studied the effect of kinematical pattern on the mechanical performance of paraplegic locomotion, in search for an improved gait pattern that leads to lower muscular efforts. A three-dimensional, four segment, ...

instruments have been traditionally used with a continuous rotary motion, but more recently, a new approach to the use of nickel-titanium instruments in a reciprocating movement has been introduced by Yared (2004). The clockwise (CW) and counter-clockwise (CCW) rotations used by Yared were four-tenths and two-tenths of a circle respectively, and the rotational speed utilized was 400 rpm. The co...