Seminar on Aj wilcock wire vs Eligilloywire

Ah wilcock vs Eligilloy comparison

1. Australian stainless steel and Elgiloy V A M Gayathri

2. EVOLUTION OF ORTHODONTIC MATERIALS Until 1930 - GOLD (at least 75%), platinum, iridium and silver alloys. Angle(1887) - German silver ( Neusilber brass - 65% cu,14% Ni, 21% Zn) Opposed by Farrar - discoloration Begg partner with Wilcock (1940) - resilient orthodontic wires - Australian stainless steel. 1919 - stainless steel introduced in dentistry 1930 – Angle used steel ligature wires Jack screws (rigid) Expansion arhes (elastic) Bands (malleable) Opposed by – Emil Herbst Gold wire – stronger than SS (1934)

3. Elgin watch company(1950s)- developed Cobalt chromium alloy ( Elgiloy ) Cobalt(40%), chromium(20%), iron (16%) & nickel(15%) . Burstone and Goldberg (1980) - b titanium(TMA) Various tempers : Red - hard & resilient Green - semi-resilient Yellow - ductile Blue - soft & formable introduced by – Rocky Mountain Orthodontics 1962 - Buehler discovered nickel-titanium named NITINOL (Nickel Titanium Naval Ordnance Laboratory) for aerospace. 1970 - Dr.George Andreason ( Unitek ) introduced NiTi to orthodontics.

4. Properties of ideal arch wires

5. STAINLESS STEEL Steel is an alloy of iron & carbon < 0.2% COMPOSITION : Iron - 71% Base element Chromium -18% T arnish and corrosion resistance Nickel- 8% Increases strength Carbon- 0.2% Molybdenum. Increases the resistance S ilicon . Deoxidizer & scavenger increases the strength Sulphur. Improves formability Manganese Increases the hardness during quenching stainless steel = Iron + carbon + 12-13% chromium Reduces the resistance ( intergranular corrosion )caused by carbide formation

6. A ccording to the AMERICAN IRON AND STEEL INSTITUTE (AISI) SYSTEM ranges from AISI 300 to 502 . Based on their microstructure and chemical composition Ferritic ( BCC ) D ue to poor weldability and workability , their use is limited High strength and hardness used to manufacture surgical instruments . Austenitic( FCC ) Most commonly used & corrosion resistant. Nickel -stabilize the austenitic phase ( fcc ) at room temperature. heated at 912°C or above Martensitic ( BCT )

7. Stainless Steel: Material Facts for the Orthodontic Practitioner Santiago Arango-Santander*, Claudia Maria Luna-Ossa Rev Nac Odontol. 2015;11(20):71-82.

8. AUSTRALIAN ORTHODONTIC WIRES Claude Arthur J Wilcock of Victoria, Australia - for use in Begg technique . Has certain unique characteristics different from usual stainless steel wires . Properties: Ultra high tensile austenitic stainless steel Highly resilient Light continuous force is generated. Zero stress relaxation -allows the wire to maintain its force over long period of time yet resists permanent deformation from elastic load.

9. Types and colour coding Available in sizes ranging from 0.010", 0.012", 0.014", 0.016", 0.018", 0.020", 0.022" round wire YIELD STRENGTH SPECIAL BLACK supplied as – spools or cut lengths of the wire. With the demand for harder wires - higher Grades premium and premium plus wires were developed

10. Dr. Prachi Gaonkar(2020) Orthodontic Archwires:Past , Present and Future(review), International Journal of Current Advanced Research, 09(05), pp 22263-22275.DOI:http//dx.doi.org/10.24327//ijcr.2020.22275.4387

11. Dr. Prachi Gaonkar(2020) Orthodontic Archwires:Past , Present and Future(review), International Journal of Current Advanced Research, 09(05), pp 22263-22275.DOI:http//dx.doi.org/10.24327//ijcr.2020.22275.4387

12. Mechanical process of straightening - resistant materials usually in the cold drawn condition. Wire- pulled through high speed, rotating bronze rollers that torsionally twist into straight condition. The resultant deformation and decreased yield stress value makes it strain softened. The wire is pulsed in special machines -permit high tensile wires to be straightened. Advantages Permits highest tensile wire to be straightened. Tensile yield stress is not altered. Smoother surface of wire less friction. Greater flexibility of springs.

13. Effects of Pulse Straightening

14. Bauschinger - first observed the relationship between permanent deformation and loss of yield strength. If you permanently deform a metal in one direction, then its yield stress is reduced in the opposite direction. Residual stresses left in the material improves its elastic properties in the direction to which the wire has been deformed. Bauschinger effect Material Facts for the Orthodontic Practitioner Santiago Arango-Santander*, Claudia Maria Luna-Ossa Rev Nac Odontol. 2015;11(20):71-82.

15. Heat treatment of Australian wire Properties of Australian wire The ultimate tensile strength for Premium Plus wire = 8-12% higher than SS wire (greater resistance to fracture in oral cavity) The pulse straightened wires > working range and show good recovery patterns. Frictional resistance of the P.S. wires < 50% than SS wire No significant difference in stress relaxation properties The low & medium grade wires (better formability) - as they are subjected to less work hardening more ductile, straightened by spinner straightening . Premium and supreme wires are straightened by a process called pulse straightening . Enables to straighten high yield strength wires , without structural deformation and altering the physical properties.

16. Ref:Refined Begg for Modern times 1 st edition– Dr.Vijay P.Jayade

17. PRECAUTION TAKEN WHILE BENDING THE WIRE Wire bent around the round beak of the pliers, the stress confined to a small area break When bending around square beak, points of stress are offset, providing more area for crystalline adjustment and therefore less chance fracture.  

18. Begg's technique is divided into 3 distinct stages of tooth movement: STAGE 1 STAGE 2 STAGE 3 Chiefly with the objective of preventing anchorage THREE STAGES OF TREATMENT

19. S TAGE 1 - OBJECTIVES •Correction of Deep Anterior Over Bite •Correction of Ante ro -posterior o cclusal relationship of the buccal segments •Correction of anterior spacing •Correction Of Crowding •Correction Of Rotations. •Correction of posterior cross bite Archwire used: 0.016 special AJW — principal wire of Stage I. •Combination of resiliency and flexibility. • Adequate stiffness for bite opening Begg PR. Light arch wire technique. Am J Orthod . 1961;47:30–48.

20. THE FIRST STAGE ARCHWIRE I NCORPORATES : • Molar anchorage bends • Toe-in or toe-out bends • Vertical loops • Bayonet bends Bayonet bends Vertical loops Toe-in or toe-out bends Tip back bends Molar anchorage bends Begg PR. Light arch wire technique. Am J Orthod . 1961;47:30–48.

21. Bend/Component Location Purpose/Action Anchor Bends (Anti-Bite Opening Bends) Mesial to the Molar Tubes The most critical bend in Stage I. gingival (upward) bend placed in the archwire , it creates: 1. Intrusive force on the anterior segment (to open the deep bite). 2. Extrusive/distal tipping force on the molar (anchorage unit). Vertical Loops (in Looped Archwire) In the interproximal spaces of the anterior teeth. Used in crowded cases to provide an extremely light, continuous, and flexible force for initial alignment and rotation correction. Loops increase the archwire's length and range of action. Intermaxillary Hooks Mesial to the Canine Brackets attachment for Class II elastics (Upper hook to Lower molar) to retract the maxillary anteriors and correct the Class II relationship, simultaneously adding to the bite-opening force. Toe-in/Toe-out Bends Distal to the molar tubes. Small horizontal bends (e.g., Toe-in for upper molars) are placed to counteract the tendency of the molars to rotate (usually mesiolingually ) due to the heavy elastic forces. Begg PR. Light arch wire technique. Am J Orthod . 1961;47:30–48.

22. STAGE 2 OBJECTIVES: 1. Maintain all corrections achieved during first stage. 2. Close any remaining posterior space. ARCH WIRE ( 0.018 SS) To maintain the corrections already achieved. T o stabilize the teeth against any adverse reciprocal forces may occur as a result of the application of elastics or auxiliaries. Begg PR. Light arch wire technique. Am J Orthod . 1961;47:30–48.

23. Bend/Component Location Purpose/Action Reduced Anchor Bends Mesial to the Molar Tubes The initial steep anchor bend is reduced to a maintenance bend .This reduction lowers the intrusive force to prevent the development of an open bite, but is kept high enough to maintain the anterior bite correction. Bayonet Bends (Offset Bends) In the archwire adjacent to incisor brackets. Small bends used to maintain or overcorrect rotations achieved in Stage I. These are vertical or horizontal offsets to keep teeth stable while spaces are closed. Intermaxillary Hooks Used throughout this stage. Still used as an attachment for Class I elastics (Canine to Molar) to pull the anterior segment distally and close the extraction space. Begg PR. Light arch wire technique. Am J Orthod . 1961;47:30–48.

24. STAGE 3 UPPER AND LOWER ARCH WIRE • Made from 0.020 SS Auxiliary/Bend Archwire Used Purpose/Action Base Archwire Bends 0.020" round wire. A heavy, rigid wire is used to resist the forces from the auxiliary springs. The anchor bend is further reduced to a minimal maintenance angle Root Uprighting Springs Auxiliary wire (often 0.009"to 0.016") slipped over the base archwire . Used on canines, premolars, and sometimes molars to provide a mesiodistal couple (force) that moves the root apex. The spring is activated to create an optimal force to upright the roots into the cancellous bone. Torquing Auxiliaries (Spur Auxiliaries) Auxiliary wire (e.g., 0.016") slipped over the base archwire . Used specifically on the six anterior teeth to apply labial or lingual root torque . This complex auxiliary is necessary because the round wire/vertical slot bracket system provides no inherent torque control. The torque spring applies a couple that twists the root faciolingually to achieve ideal inclination. Begg PR. Light arch wire technique. Am J Orthod . 1961;47:30–48.

25. Case report : A 14yr old male with class 2 div 1 malocclusion with open bite and crowding in both arches Beginning of treatment After 4 weeks of alignment with .0009” supreme wire Miles PG. Rapid alignment with a high-tensile wire. J Clin Orthod . 1994 Feb;28(2):74-6. PMID: 8040245.

26. COBALT CHROMIUM ALLOY Developed (1950’s) by Elgiloy Corporation (Elgin, IL,USA). Initially it was manufactured for watch springs by Elgin watch company, hence the name Elgiloy . Rocky Mountain Orthodontics first introduced Co-Cr wires by name ElgiloyTM Various tempers : Red - hard & resilient Green - semi-resilient Yellow - ductile Blue - soft & formable AVAILABILITY : Available commercially as Elgiloy - Rocky Mountain orthodontics Azurloy - Ormco Corporation Multiphase - American Orthodontics Flexiloy - Unitek Corporation

27. COMPOSITION 40% cobalt 20% chromium 15% nickel 7% Molybdenum 2% manganese 0.16% carbon 0.04% beryllium 15.8% iron.

28. PROPERTIES 1. SPRINGBACK: except of red elgiloy non-heat-treated CO-Cr wires have smaller springback than SS wires of comparable sizes. can be improved by adequate heat treatment. .0045-.0065-for soft as received wire .0054-.0074 after heat treatment 2. STIFFNESS: High Modulus of elasticity Deliver twice force of beta - Ti and 4 times force of Niti for equal amounts of activation. 160-190GPa as received 180-210GPa heat treated

29. 3. FORMABILITY: Good - Modified by heat treatment. yield strength-830-100MPa as received 1100-1400MPa heat treated 4. JOINTABILITY: Can be soldered and welded. Precaution :- High temp (749 °C ) causes Annealing. Low fusing solder is recommended. 5. BIOCAMPATABILITY – Good 6. FRICTION: larger frictional forces between brackets and co- cr wires, recent - resistance to tooth movement along stainless steel and co- cr comparable.

30. Temperature and Time :- 900 ° F (482 ° C) for 7 - 12 min in a dental furnance . Temp above 1200 ° F (749 ° C) results in partial annealing - in resistance to deformation. Optimum levels of heat treatment are confirmed by : Dark straw-colored wire. Temp indicating paste HEAT TREATMENT OF ELGILOY

31. MECHANISM : Precipitation Hardening Results in resistance of wire to deformation. properties similar to ss. PROCEDURE Three heat treatment procedures are recommended. Oven heat treatment. Electrical heat treatment - using a heat treatment unit and temperature indicating paste to achieve proper heat treatment temperature. Wet cotton is placed over bends in wire to prevent overheating the wire. Flame heat treatment with match or brush flame. Uniform results are not attained.

32. Martin et al (1984) :- Investigated effect of heat treatment on various properties of Elgiloy . • Heat treatment (blue Elgiloy ) - yield strength & stiffness no. of 90-degree bends cycles to failure. yield strength of electrically heat treated > oven heat treated wires was noted.

33. CLINICAL APPLICATIONS Easier to bend than SS, NiTi and ß-Ti in its "as received state". Preferred in techniques in which loops are used. Along with SS considered most ideal and economical finishing wire. Quad helix ADVANTAGES OVER SS WIRES Greater resistance to fatigue and distortion. Longer function as a resilient spring. excellent corrosion resistance DRAWBACKS : High elastic force delivery similar to that of SS Lower spring back than stainless steel

34. Heat treatment of Elgiloy wires led to a significant increase in stiffness, modulus, percent recovery, and force values required to deflect the wire at various deflection measurements. Therefore, further research and investigation is needed to determine how heat treatment of Elgiloy wires can influence their clinical use.

35. The mechanical characteristics investigated among the 4 tempers of a cobalt-chromium product. each wire was measured to determine its elastic modulus,its yield strength, ultimate tensile strength, and ductility. Result: the formability sometimes followed expectations, but the flexibility and resilience characteristics were variable and independent of temper. And although the elastic modulus was affected by the loss of material at the corners of rectangular wires. Overall, the stiffnesses of cobalt-chromium wires in round configurations were comparable to those of multi- and single-stranded stainless steel wires but were 3 and 6 times greater than the stiffnesses of beta-titanium and nickel-titanium wires , respectively. In the final analysis, these as-received wires do not meet their potential as a variably formable and variably resilient alternative to stainless steel . Perhaps this is why cobalt-chromium wires have never had the impact on the profession that was expected from them several years ago. (Am J Orthod Dentofacial Orthop 2001;119:274-91)

36. REFERENCE: Material Facts for the Orthodontic Practitioner Santiago Arango-Santander*, Claudia Maria Luna-Ossa Rev Nac Odontol. 2015;11(20):71-82. Miles PG. Rapid alignment with a high-tensile wire. J Clin Orthod . 1994 Feb;28(2):74-6. PMID: 8040245. Material Facts for the Orthodontic Practitioner Santiago Arango-Santander*, Claudia Maria Luna-Ossa Rev Nac Odontol. 2015;11(20):71-82. Dr. Prachi Gaonkar(2020) Orthodontic Archwires:Past , Present and Future(review), International Journal of Current Advanced Research, 09(05), pp 22263-22275.DOI:http//dx.doi.org/10.24327//ijcr.2020.22275.4387 Refined Begg for Modern times 1 st edition– Dr.Vijay P.Jayade Begg PR, Kesling PC. Begg Orthodontic Theory and Technique.Philadelphia , Pa: WB Saunders; 1977:94–96. Begg PR. Light arch wire technique. Am J Orthod . 1961;47:30–48.