Catalog | G&H® Orthodontics (800) 526-1026 | +1 317-346-6655 | Email: G&H Orthodontics® 51 Material Science / Scientific Testing G&H® NiTi archwires deliver the clinical expectations of extreme elasticity, consistent force, and shape memory, realized over a range of deflection. Description: .016 G4™ Niti Test Temp: 36 °C G&H Orthodontics® is a recognized leader in manufacturing Nickel Titanium wire products. Continuous and meticulous testing of our wires ensures the high standards of performance we guarantee. State-of-the-art stress/ strain testing of Nickel Titanium wire is performed employing a three-point deflection test (fig. A) with a load cell probe impacting a wire and recording the forces throughout the range from deflection to recovery. The test data (force vs. deflection) is validated on a daily basis to meet our stringent specifications. The data is then documented and archived on a hysteresis graph (fig. B). FORCE Hysteresis Graph (fig. B) 100.0 G 200.0 G 300.0 G 400.0 G 500.0 G 1 2 3 4 5 6 Extreme elasticity shown by the Load Resistance Force (bump in the graph) at 0.6mm deflection • This wire is active and aggressive as it transitions from the Austenitic (increasing force) to Martensitic (constant force) state Start test – Load cell contacts wire and begins deflection in 36 °C waterbath Consistent forces of martensitic response • Engagement forces have “flatlined” at 230g as the wire is deflected from 0.6mm to 2.0mm • Desired, defined excursion of Martensitic phenomenon (constant force over a large deflection) exhibited represents properties unique to effective Superelastic Niti wire Extreme elasticity and consistent force shown at 3.0mm deflection • Peak load force of 230g at 2.0mm deflection is consistent with force levels at the 0.6mm deflection point during engagement • Transitional rebound shows the wire is active and aggressive as engagement forces cease and recovery forces begin applying tooth moving force Shape memory and elasticity are expressed • Full shape memory rebound occurs at 130g ensuring continuity of effective tooth moving forces through complete shape recovery Consistent unload force as Martensitic state is reentered during recovery • Tooth moving forces dissipate slightly then stabilize to ensure consistent unload to shape memory. How a hysteresis graph demonstrates if a NiTi wire will fulfill the clinical expectations of elasticity, consistent force and shape memory. -0.10 .0 mm 0.5 mm 1.0 mm 1.5 mm 2.0 mm 2.5 mm 3.0 mm 3.5 mm 4.0 mm Engagement Force Tooth Moving Force DEFLECTION Wire Products Testing Three-point deflection testing to measure force values Load Cell Wire Engagement Force Tooth Moving Force (Recovery / Unload) (fig. A) 3mm Deflection ANSI/ADA Specifications #32, Orthodontic Wires: 2017 (Delivery / Load) 10mm span 6 1 2 3 4 5