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be welded and had good formability. When compared with SS, TMA produced greater linear forces per unit of deactivation and had more range and springback. Beta titanium wires also deliver about half the amount of force as do comparable stainless steel wires for example, and 0.018” x 0.025” inch beta -titanium wire delivers approximately the same force as a .014” x .020” SS in a second-order activation. The former configuration has the added advantage of full bracket engagement and a resultant greater torque control than the smaller stainless steel wire.27 The good formability of beta-titanium wire allows stops and loops to be bent into the wire. However, Burstone and Goldberg recommend that these wires should not be bent over a sharp radius. Helices that are commonly used with stainless steel to lower that load deflection rate of the appliance may not be necessary with beta-titanium wires because of their low modulus of elasticity and high springback. This helps to simplify appliance design by eliminating the need to place loops and helices in the wire.28 It is possible to attach stops, hooks, and active auxiliaries by welding to beta- titanium wires, thereby increasing the versatility of the wire. However, adequate strength of the weld without loss in wire properties is achieved within a narrow optimal voltage setting on a resistance spot welder. Nelson, Burstone, and Golberg have provided values for these optimal voltage settings. A flat-to-flat electrode configuration is recommended for welding because it produces a strong joint with low levels of distortion. Overheating of the wire causes it to become brittle.28,29 Beta-titanium has a corrosion resistance comparable to stainless steel and cobalt -chromium alloys. Beta-titanium wires demonstrate higher levels of bracket / wire friction than either Stainless Steel or Co-Cr wires. This may imply slower rates of tooth movement during canine retraction and space consolidation with beta- titanium wire than, with stainless steel or co-cr wires. Absence of nickel makes it useful in patients allergic to nickel.30 The composition of TMA is: Titanium 79% Molybdenum 11 % ‘I Zirconium 6% Tin 4% The metastable BCC structure of Titanium can be retained at room temperatures by using a variety of allowing additives such as Molybdenum, Vanadium or Chromium and the final properties can be significantly altered by the thermal and mechanical processing used to produce the small diameter wire. In TMA, the friction is probably due to its relative softness, and surface treatment by Ion can increase the hardness and reduce the coefficient of friction of TMA wire while maintaining its desirable mechanical properties, Ion implantation is a process by which various elements or compounds are joined arid then accelerated toward target -in this case, the orthodontic archwire. Ion implantation takes place in a vacuum chamber, in which a Vapor flux of Ions is generated with an electron beam evaporator and deposited on the substrate. Gas ions nitrogen and oxygen are simultaneously extracted from plasma and accelerated in the growing physical vapor deposition film at energies of several hundred to several thousand electron volts. Various colored TMAS (purple, Violet, aqua honey dew) are produced by IJO

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Ion implantation. They have the same coefficient of friction as stainless steel and in some cases (purple, honeydrew) even lower.30 The Ions penetrate the surface of the wire on impact, building up a structure that consists of both the original wire and a layer of tin compounds (TIN and TIO) on the surface and immediate subsurface. This layer is extremely hard and creates a considerable amount of compressive forces in the material at the atomic level. The compressive forces and the increased surface hardness improve the fatigue resistance and ductility and reduce the coefficient of friction of the wire. The superficial compressive forces also minimize any detrimental effects of surface flaws.30 Unlike conventional coating process, ion implantation produces no sharp interface between coating and wire, which can lead to bond failure or delamination. Also unlike coating ion implantations does not alter wire dimensions; thus it allows the production of high quality wires with close dimensional tolerances. The depth, distribution and concentration profile can be controlled by varying the ion dosage and energy. Ion implantation can take place at relatively low temperatures -from subzero to 700°C. The thickness of the implanted surface layer can be precisely controlled and its properties engineered to affect characteristics such as hardness, friction, wear resistance, ductility and fatigue resistance.30 Reverse curve TMA TMA with reverse curve of spee is ideal for bite opening, arch leveling, space closure and early three-dimensional manipulation and torque control. In addition ,this arch wire provides the mechanics necessary for leveling deep bites and countering undesirable tipping tendencies during space closure. With twice the resiliency of stainless steel, TMA delivers continuous, uniform forces for rapid,efficient tooth movement. Reverse curve TMA with “T”Loops Reverse Curve TMA with “T” loops offers a superior titanium alloy with proven treatment mechanics. The “T” loop design allows for effective anterior retraction, intrusion of anterior segment and torquing. Low friction and colored TMA If sliding mechanics and minimum friction are your goals, then colored low friction TMA is the choice of wire. Ion beam implantation procedure provides wire that has the same coefficient of friction as stainless steel and in some cases even lower. Timolium Archwire These are intermediary in properties between TMA and Stainless steel wires. It is an excellent addition in clinician’s armamentarium. Titanium Niobium-FA (Finishing Archwire) Designed for precision tooth to tooth finishing. Its unique metallurgical properties allow most precise intra oral detailing option available today. At 80% of the stiffness of TMA, it is perfect for holding bends yet light enough not to override the arch to arch relationship which is very hard to achieve. 53

International Journal of Orthodontics  
International Journal of Orthodontics