OBJECTIVES Since the low friction of NiTi wires allows a rapid and efficient orthodontic tooth movement, the aim of this research was to investigate the friction and surface roughness of different commercially available superelastic NiTi wires before and after clinical use. The surface of all of the wires had been pre-treated by the manufacturer. MATERIALS Forty superelastic wires (Titanol Lo...

The aim of the present study was to investigate slot deformation and the equivalent torque capacity of polycarbonate brackets with and without a metal slot in comparison with those of a metal bracket. For this purpose, the expansion characteristics and, in a further investigation, the labial crown torque of an upper central incisor, were measured in a simulated intra-oral clinical situation, us...

The purpose of this study was to measure the efficacy of anchorage control between differential moments mechanics and temporary anchorage devices in a clinical trial. Forty-six patients requiring extraction of maxillary first premolars were allocated into 2 treatment groups. The differential moments group (G1) received a nickel titanium (NiTi) intrusion arch and a 150g NiTi closing coil spring ...

BACKGROUND Friction between archwires and brackets is assuming greater importance for finishing with increased use of sliding mechanics in orthodontics as friction impedes the desired tooth movement. The following study is conducted to compare and evaluate the effect of ligation on friction in sliding mechanics using 0.022" slot bracket in dry condition. MATERIALS & METHODS In the study 48 co...

The porpose of this study was to determine the optimal length of power arms for achieving controlled anterior tooth movement in segmented arch mechanics combined with power arm. A three-dimensional finite element method was applied for the simulation of en masse anterior tooth retraction in segmented power arm mechanics. The type of tooth movement, namely, the location of center of rotation of ...

background: the advantages of coated orthodontic wires such as esthetic and their effectson reduced friction, corrosion and allergic reaction and the signifi cant consequences of plaque accumulation on oral health encouraged us to assess bacterial colonization on these wires. materials and methods: a total of 18 (9 upper and 9 lower) epoxy resin coated 16 × 22 nickeltitanium wires (spectra, gac...

background: wearing spectacles is the most common approach in correcting the refractive errors worldwide. due to harmful effects of overexposure to solar ultraviolet radiations, the usage of multi-layer coatings in ophthalmic lenses has recently been increased. these lenses can reduce the reflections and hence increase the transmission of visible light; they can also decrease the transmission o...