Rectangular Stainless Steel Wires Research Articles

Archwire depth is a significant parameter in the frictional resistance of active and interactive, but not passive, self-ligating brackets

To elucidate some of the parameters determining the frictional behavior of passive, active, and interactive self-ligating brackets during sliding mechanics. A custom jig mimicking the three-dimensional tooth movements that occur during sliding mechanics and an Instron testing machine were used to determine the resistance to sliding of six different self-ligating brackets (SPEED, In-Ovation C, CarrièreSLB, ClaritySL, SmartClip, VisionLP). Each bracket was tested on three rectangular stainless steel wires: 0.017 × 0.022 inch, 0.017 × 0.025 inch, and 0.019 × 0.025 inch. A two-way balanced analysis of variance was used for statistical analysis. The four passive self-ligating brackets (CarrièreSLB, ClaritySL, SmartClip, VisionLP) displayed significantly lower frictional resistance (P < .001) than the remaining brackets, which featured an active (SPEED) or interactive (In-Ovation C) clip. The SPEED bracket consistently demonstrated the highest resistance to sliding. The mode of self-ligation appears to be the primary variable in determining the frictional behavior of orthodontic brackets undergoing sliding mechanics. Passive self-ligating brackets demonstrated significantly lower frictional resistance to sliding. With regard to the resistance of active self-ligating brackets, the depth (buccolingual thickness) of the wire had a more significant influence than its height.

Frictional Resistance between Orthodontic Brackets and Archwire: An in vitro Study

The purpose of this investigation was to determine the kinetic frictional resistance offered by stainless steel and Titanium bracket used in combination with rectangular stainless steel wire during in vitro translatory displacement of brackets. In this study. Brackets: (All brackets used had a torque of - 7° and an angulation of 0°): (1) Dynalock (Unitek) 0.018'' slot, 3.3 mm bracket width, (2) Mini Uni-Twin (Unitek) 0.018'' slot, 1.6 mm bracket width, (3) Ultra-Minitrim (Dentaurum) 0.022'' slot 3.3 mm bracket width, (4) Titanium (Dentaurum) 0.022'' slot, 3.3 mm bracket width. WIRES: (1) 0.016 x 0.022'' stainless steel (Dentaurum), (2) 0.017 x 0.025''stainless steel (Unitek), (3) 0.018 x 0.025'' stainless steel (Dentaurum), elastomeric modules (Ortho Organisers), 0. 009'' stainless steel ligature wires, hooks made of 0.021 x 0.025'' stainless steel wires, super glue to bond the hooks to the base of the bracket, acetone to condition the bracket and wires before testing and artificial saliva. Brackets were moved along the wire by means of an Instron universal testing machine (1101) and forces were measured by a load cell. All values were recorded in Newtons and then converted into gms (1N-102 gm). 200 gm was then subtracted from these values to find out the frictional force for each archwire/bracket combination. For each archwire/ bracket combination three readings were taken under wet and dry condition and also with stainless steel ligature and elastomeric modules separately. The results showed that narrow brackets generated more friction than wider brackets. Frictional force was directly proportional to wire dimension. Titanium brackets generated more friction than stainless steel brackets. Archwire and bracket ligated with elastomeric module generated more friction than when ligated with stainless steel ligature wire. Frictional forces in the wet condition were greater than in the dry condition for all archwire to bracket combinations. Frictional force was seen to be inversely proportional to bracket width, frictional force was inversely proportional to bracket width, and in the wet condition were greater than in the dry condition for all archwire to bracket combinations. This study of friction is its role in lessening the force actually received by a tooth from an active component such as a spring, loop or elastic. Hence greater applied force is needed to move a tooth with a bracket archwire combination demonstrating high magnitudes of friction compared with one with a low frictional value.

In-vitro evaluation of frictional resistance with 5 ligation methods and Gianelly-type working wires

Numerous in-vitro studies have been conducted with various archwire-ligation combinations to evaluate the effect of wire size and ligation method on frictional resistance. The aim of this in-vitro study was to compare the frictional resistance during sliding mechanics with Gianelly-type stainless steel working wires, Leone slide ligature, conventional elastic ligature, and stainless steel (SS) ligature, and a conventional bracket and active and passive self-ligating brackets. Three ligation methods with Victory (V) brackets--Leone (VLeone), conventional (regular) elastic (VReg), and SS (VSS)--were used with standard SS brackets, and 2 self-ligating brackets--Damon MX (Ormco/"A", St. Paul, Minn) (DMX) and In-Ovation R (GAC Intl., Bohemia, NY)--were used with 2 rectangular SS wires (0.016 x 0.022 and 0.018 x 0.022 in). Therefore, 5 ligation methods and 2 wire sizes were evaluated with respect to their effects on frictional resistance. No statistically significant differences were found between the SS ligation method and DMX (neither produced measurable static friction). For the wire size 0.016 x 0.022-in SS, the DMX and SS produced significantly less static friction than the In-Ovation R, VLeone, and VReg. The In-Ovation R produced significantly less friction than both the VLeone and VReg, whereas the VLeone produced significantly less friction than the VReg. For the wire size 0.018 x 0.022-in SS, the overall results were the same, except that the In-Ovation R produced significantly more friction than the VLeone. An increase in wire size (from 0.016 x 0.022 to 0.018 x 0.022 in) led to an increase in friction in all bracket-archwire combinations (except DMX and VSS, which showed no measurable friction at either wire size). The Leone slide ligature showed less friction at both wire sizes than VReg; however, it showed significantly more friction than both DMX and VSS. DMX and VSS brackets produced no measurable friction with either 0.016 x 0.022-in or 0.018 x 0.022-in wires. An increase in wire size (from 0.016 x 0.022 to 0.018 x 0.022 in) led to an increase in friction in all bracket-archwire combinations (excluding DMX and VSS, which showed no measurable friction at either wire size).

Cutting efficiency of 3 different instrument designs used in reciprocation

This study examined the effect of flute number and cross-sectional area on the cutting efficiency of 3 reciprocating endodontic instruments twisted from rectangular stainless steel wire; 40/0.02 instruments at 25-mm length were compared. Seventy-five anterior teeth were prepared, divided into 3 groups, and operated on with a reciprocating handpiece at 2500 rpm for 5 seconds at around 500 grams of force: Group 1, SafeSiders; Group 2, Dentsply K-Files; Group 3, Dentsply K-Reamers. Dentin generated was collected in weigh dishes. Cutting efficiency was determined by dentin weight. Statistical analysis was performed with 1-way ANOVA and the Student-Neuman-Keuls (SNK) multiple comparisons testing. SafeSider instruments produced a greater amount of debris than K-Files and K-Reamers (P < .026). K-Files and K-Reamers were not statistically different (P = .63). Flute number had no effect on cutting efficiency. Cross-sectional area may be a determining factor on cutting efficiency.

Static frictional resistance with the Slide low-friction elastomeric ligature system

Abstract Aim This ex-vivo study compared the static frictional resistance of a low-friction ligation system against a conventional elastomeric module, and studied the effect of storage in a simulated oral environment on the static frictional resistance of both ligation systems. Methods Eighty stainless steel brackets were tested by sliding along straight lengths of 0.018 inch round and 0.019 x 0.025 inch rectangular stainless steel wires ligated with either conventional elastomerics or the Slide system (Leone, Florence, Italy). During the tests the brackets and wires were lubricated with artificial saliva. A specially constructed jig assembly was used to hold the bracket and archwire securely. The jig was clamped in an Instron universal load testing machine. Crosshead speed was controlled via a microcomputer connected to the Instron machine. The static frictional forces at 0 degree bracket/wire angulation were measured for both systems, fresh from the pack and after storage in artificial saliva at 37 °C for 24 hours. Results The results of this investigation demonstrated that the Slide ligatures produced significantly lower static frictional resistance than conventional elastomeric modules in the fresh condition and after 24 hours of storage in a simulated oral environment (p &lt; 0.001). Storage for 24 hours in artificial saliva had no effect on the static frictional resistance of conventional elastomeric modules and the Slide system (p = 0.525). Conclusions The claim by the manufacturer that the Slide system produces lower frictional resistance than conventional elastomeric modules is upheld.

Clinical Variability in Arch Wires: A Preliminary Study Evaluating Mechanical and Surface Characteristics of Two Different Sized Rectangular Stainless Steel Wires

Experimental characterization of arch wires has been performed in many previous studies; however with the advent of new arch wire materials being introduced, some new experimental methods and characterization are required. Since literature is available for comparison, this paper examines mechanical and physical characteristics of steel arch wires to quantify their variability in engineering terms. Furthermore, the effect of wire size on properties was evaluated using two of the most common wire sizes. Finally, manufacturing consistency was verified by testing samples from different lots.

Clinical Variability in Arch Wires: A Preliminary Study Evaluating Mechanical and Surface Characteristics of Two Different Sized Rectangular Stainless Steel Wires

Experimental characterization of arch wires has been performed in many previous studies; however with the advent of new arch wire materials being introduced, some new experimental methods and characterization are required. Since literature is available for comparison, this paper examines mechanical and physical characteristics of steel arch wires to quantify their variability in engineering terms. Furthermore, the effect of wire size on properties was evaluated using two of the most common wire sizes. Finally, manufacturing consistency was verified by testing samples from different lots.

Static frictional resistances of polycrystalline ceramic brackets with conventional slots, glazed slots and metal slot inserts

Abstract Aims To compare the static frictional resistance of ceramic brackets with a conventional slot (Allure), a glazed slot (Mystique) and a metal slot insert (Clarity). Method Twenty five brackets of each type, with slot size 0.022 x 0.028 inch and Roth prescription were tested by sliding against straight lengths of 0.019 x 0.025 inch rectangular stainless steel wire. During the tests the brackets and wire were lubricated with artificial saliva. Static frictional forces at three different simulated binding angulations (0, 5 and 10 degrees) were measured for each type of bracket. Results At each of the angulations tested, the Clarity brackets produced the lowest static frictional resistance. At 0 degree angulation (below the critical angle for binding) the Allure brackets produced the greatest friction. The difference in friction between the Clarity and Mystique brackets was not statistically significant. As the angulations were increased to 5 degrees the Allure brackets again produced the greatest frictional resistance, although this was not significantly higher than the Mystique brackets. The Mystique brackets produced the greatest frictional resistance at 10 degrees, but again there was no statistical difference from the Allure brackets. Conclusions A glazed slot ceramic bracket demonstrates low frictional resistance at non-binding angulations and compares favourably with a metal slot ceramic bracket. Increasing angulations through 5 to 10 degrees of simulated binding results in high levels of static frictional resistance such that the bracket behaves more like a conventional polycrystalline ceramic bracket.

Mechanical Properties and Surface Characterization of Beta Titanium and Stainless Steel Orthodontic Wire Following Topical Fluoride Treatment

To study the effect of fluoride prophylactic agents on the loading and unloading mechanical properties and surface quality of beta titanium and stainless steel orthodontic wires. Rectangular beta titanium and stainless steel wires were immersed in either an acidulated fluoride agent, a neutral fluoride agent, or distilled water (control) for 1.5 hours at 37 degrees C. After immersion, the loading and unloading elastic modulus and yield strength of the wires were measured using a 3-point bend test in a water bath at 37 degrees C. A one-way analysis of variance and Dunnett's post hoc, alpha = .05, were used to analyze the mechanical testing data. Scanning electron microscopy was also used to qualitatively evaluate the wire topography as a function of the fluoride treatments. Unloading mechanical properties of beta titanium and stainless steel wires were significantly decreased (P <or= .05) after exposure to both fluoride agents. Corrosive changes in surface topography were also observed after exposure to both the neutral and the acidulated phosphate fluoride agents. The results suggest that using topical fluoride agents with beta titanium and stainless steel wire could decrease the functional unloading mechanical properties of the wires and potentially contribute to prolonged orthodontic treatment.

Static frictional resistances of polycrystalline ceramic brackets with metal slot inserts

Abstract Aims To compare the static frictional resistances of polycrystalline ceramic brackets with a gold slot insert (Desire), a stainless steel slot insert (Clarity), a conventional polycrystalline ceramic bracket (Transcend 6000) and a stainless steel bracket (Ultratrimm). Methods Twenty five brackets of each type were tested by sliding against straight lengths of 0.019 x 0.025 inch rectangular stainless steel wire. During the tests the brackets and wire were lubricated with artificial saliva. Static frictional forces at three different binding angulations (0, 5 and 10 degrees) were measured for all brackets. Results Statistically significant increases in static frictional resistance were found as the bracket/wire angulation increased from 0 through 5 to 10 degrees for all bracket types. At angulations below the critical binding angle the Ultratrimm brackets produced the greatest friction and the Transcend 6000 brackets produced the least friction. As the angulation increased the Transcend 6000 brackets produced greater friction than the other brackets. At the highest angulation (10 degrees), the Ultratrimm brackets produced significantly less friction and the Transcend 6000 brackets produced significantly more friction than the other brackets. The Desire and Clarity brackets produced comparable results: there were no statistically significant differences between these two brackets for static friction at any of the angulations. Conclusions Polycrystalline ceramic brackets with either stainless steel or gold slot inserts produced similar static frictional resistances to sliding. At binding angulations, the brackets with inserts demonstrated consistently lower static frictional resistances than a conventional ceramic bracket.

M/F ratios of four different closing loops: 3D analysis using the finite element method (FEM)

Abstract Background It has been claimed that the opus loop is capable of delivering a constant and optimum M/F ratio without the need for gable bends. Objective To compare the forces, moments and moment/force (M/F) ratios of the opus loop, L–loop, T–loop and vertical helical closing loop (VHC loop) in a segmented arch with the finite element method (FEM). Methods The FEM was used to compare 3D models of closing loops in rectangular (0.016 x 0.022 inch) stainless steel wire. The L–, T– and VHC loops were designed with and without preactivation bends. The opus loop had no preactivation bends. The T–Loops were 10 mm in height and 10 mm in length. The horizontal and vertical forces, the moments and the M/F ratios at the alpha and beta ends were recorded at 0, 0.1, 0.4, 0.7 and 1 mm intervals. Results The highest horizontal and vertical forces were produced by the L–loop (with and without preactivation bends) and in most cases the lowest forces were produced by the VHC loop. Loops with preactivation bends produced marked changes in the M/F ratio and loops without preactivation bends low, but relatively constant, M/F ratios over the full range of activation. Of the loops modelled without preactivation bends the opus and T-loop had the highest M/F ratios (7.20 – 7.67 mm at the anterior ends). Conclusion Stainless steel opus and T–loops without preactivation bends had constant M/F ratios, but both loops failed to deliver the optimum M/F ratio of 10:1.

PG canine retraction spring

PG canine retraction spring was introduced to the orthodontic profession way back in 1985 by Poul Gjessing; it was not widely used till interest in it was renewed in recent years because of its adaptability to the now commonly used 0.018” pre-adjusted edgewise appliance system. The efficient design as well as the relatively rigid stainless steel wire, lends good stability to this retraction spring for use in frictionless orthodontic mechanics. Canine retraction is a very important step in most orthodontic procedures involving extraction of premolar teeth and is usually carried out by two methods: 1) Retracting canines by sliding along a base wire (Frictional mechanics) 2) Retracting the canine with a specially designed spring attached to it without any base arch wire for the canine to slide on (Frictionless mechanics) Contemporary Orthodontics by Proffit [1] describes the PG spring to be the most efficient current design for frictionless canine retraction. Rectangular stainless steel wire with overlapping ovoid loops provide good stability, required moment-force ratio and good load deflection rates. It is constructed in the readily available 0.016″x0.022″ stainless steel wire and can be easily placed in the routinely used 0.018” brackets. Construction and placement is easy and so is the activation. Its advantage as compared to other retraction springs is the fact that it can be economically made and used within the routine inventory of an average orthodontic clinic. Disadvantages are the same as in any retraction spring, in not being failsafe in case of accidental distortion and being liable to irritate the sulcular mucosa at least in the initial few days. Construction: The PG spring [2, 3, 4] is made in 0.016″x.022″ stainless steel rectangular wire. It has gingivally directed overlapping double helices, ovoid in shape, 10mm in height and 5.5mm at its widest part (Fig 1). It also has a small occlusal helix 2mm in diameter. The wire is bent in such a way that the smaller end of the wire is continuous with the occlusal helix. This portion is the canine part and would fit into the canine bracket. As it comes out of the occlusal helix, it is given a 15° gingival turn. After forming the gingivally directed double helices, the longer arm of the wire is the one which is meant for engaging the premolar bracket and the molar tube; this being the molar portion. This posterior molar arm as it exits from the double ovoid loops is turned gingivally such that the wire makes an angle of 12° till approximately the second premolar bracket and then turned up at an increased total angulation of 30° as shown in Fig 1. This portion is also given an anti-rotation bend of 60° towards the canine tooth and then this bend after traversing the width of the spring is curved back in an exactly opposite direction of the initial bend decreasing this to a final 35° (Fig 2). Fig. 1 Right upper PG spring (palatal view) Fig. 2 Right upper PG spring (occlusal view) Placement and activation: The anterior end emerging out from the smaller helix is placed as close as possible to the canine bracket and the front end is cinched. The posterior end is placed into the second premolar bracket and then into the 1st molar tube. The spring is pulled back till the double ovoid gingival loops open by 1mm and cinched back. This gives an approximate force of 160 grams. A retraction of 1.5 mm is expected in one month. The PG spring in use is shown in Fig. 3, Fig. 4. Fig. 3 PG canine retraction spring before retraction Fig. 4 PG canine retraction spring after retraction The spring induces bodily movement of teeth and anchorage, reinforcement by a Nance button or headgear is needed in moderate to high anchorage cases. A prerequisite before placing this spring is good rotational correction as well as levelling and alignment of the three teeth involved.

A radiographic comparison of apical root resorption after orthodontic treatment with 3 different fixed appliance techniques

Apical root resorption is an undesirable, but frequent side effect of orthodontic treatment, and therefore improvements in orthodontic techniques and materials are in constant development to decrease it. One of the most recently developed orthodontic techniques is the Bioefficient Therapy that uses contemporary orthodontic materials. Therefore, the primary objective of this study was to compare the amount of root resorption after orthodontic treatment between the simplified standard edgewise technique (group 1), the edgewise straight wire system (group 2), and the Bioefficient Therapy (group 3). It was also the purpose of this investigation to evaluate the amount of root resorption in the whole sample studied and the prevalence of root resorption in the upper and lower incisors. Thus, periapical radiographs were obtained with the long cone paralleling technique for the upper and lower incisors from 30 patients for each group. Root resorption was ranked by scores by 2 examiners who had an excellent intra and interexaminer calibration by Kendall concordance coefficient. Results of the Kruskal-Wallis test demonstrated that group 3 (Bioefficient Therapy) presented less root resorption than the others. It was speculated that the factors responsible for the lesser resorption in this technique were the use of heat-activated and superelastic wires with the bracket design in this technique as well as the use of a smaller rectangular stainless steel wire (0.018 × 0.025 inch) in a 0.022 × 0.028 inch slot during incisor retraction and the finishing stages, as compared to the other techniques. Considering the whole sample, there was no root resorption in 2.25% of the analyzed teeth. There was only a slight resorption in 42.56%, a moderate resorption in 53.37%, an accentuated resorption in 1.40% and an extreme root resorption in only 0.42% of the teeth. The prevalence of resorption for each incisor indicated, in decreasing order, a greater resorption for the upper centrals, followed by the upper laterals, lower centrals, and lastly the lower lateral incisors. (Am J Orthod Dentofacial Orthop 1999;118:262–73)

Comparison of frictional resistance in titanium and stainless steel brackets

This study measures and compares the level of frictional resistance generated between titanium and stainless steel brackets. Both 0.018 and 0.022 inch slot size edgewise brackets were tested with different sized rectangular stainless steel wires in a specially designed apparatus. The frictional resistance was measured on Instron Universal testing machine (Instron Corp, Canton, Mass) with a 10 pound load cell. The specimen population was composed of 180 brackets and 180 wire specimens. A completely randomized design (one way) ANOVA was used to test for significant differences among the three bracket/wire types in the 0.018 and 0.022 inch slot sizes. This was followed by the Student Newman Keuls Multiple Comparison of means ranking at P < .05 to determine differences between the different groups. The titanium brackets showed lower static and kinetic frictional force as the wire size increased, whereas stainless steel brackets showed higher static and kinetic frictional force as the wire size increased. (Am J Orthod Dentofacial Orthop 1999;116:271-4)

On mechanical properties of square and rectangular stainless steel wires tested in torsion

Forty different sizes and types of square and rectangular stainless steel wires, supplied by five different manufacturers, were tested in torsion. The study simulated the situation occurring when torque is applied to an individual tooth. We used standard brackets with 0.018-inch slot heights, with an interbracket distance of 4 mm. The results show that variation in cross-sectional dimension and edge bevel leads to variable torsional play (third-order clearance). As an example 0.016 x 0.022-inch wires have a mean torsional play of as much as 18.5 degrees, with a range of 16.6 degrees to 20.4 degrees. We have shown that when 0.016 x 0.022-inch wires are used, one must apply from 24.6 degrees to 29.2 degrees of twist to get 20 Nmm of torsional moment. This variation is mostly due to a rather wide range in torsional play. As a result, the prediction by which a predetermined torsional moment can be delivered becomes uncertain. The results show that because the working range in torsion of stainless steel wires is somewhat limited, precise delivery of torsional moment, based on the condition present in the oral cavity, is difficult. Torsional stiffness varies considerable within the various dimensional groups, this being the result of variation in cross-sectional geometry and material properties.

On mechanical properties of square and rectangular stainless steel wires tested intorsion

On mechanical properties of square and rectangular stainless steel wires tested intorsion