Load Deflection Rate And Properties Of Three Different Brands Of Single Strand Superelastic CuNiTi - A Material Study

Introduction: Niti alloys are superelastic alloys whose mechanical properties allow them to exert light continuous forces enabling them to have a greater working range. Orthodontic forces are transmitted through wires which, when engaged tightly in brackets, try to attain its original shape owing to its resiliency and springback properties. Aim: This study aims to assess the load deflection rates of three different types of superelastic CuNiTi with thermal reactive properties. Materials and methodology: Three samples, thirty each, of Damon CuNiTi, Captain Ortho CuNiTi, and Galaxy Orthodontics CuNiTi orthodontic archwires were taken. All the samples were 0.016 inch indiameter. The load deflection rates were tested by the Universal Testing Machine (Instron). A three-point bending test was used with a single pointer placed in between the wire between two flat planks. The laboratory conditions were standardized. Force was exerted at a rate of 1mm/minute upto a total deflection of 5mm. The force levels delivered during the intervals was measured and they were plotted as loading and unloading curves in the load-deflection diagram. Results: In Galaxy Orthodontics, the force levels delivered from intervals (0-1mm, 1-2mm, 2-3mm, 3-4mm, 4-5mm) were 2.76N, 0.13N, 0.73N, 0.09N and 1.15N during the loading period. For the unloading period, the force levels delivered from intervals (5-4mm, 4-3mm, 3-2mm, 2-1mm, 1-0mm) were 0.58N, 0.46N, 1.34N, 1.00N and 0.34N respectively.In Captain Ortho, the force levels delivered from intervals (0-1mm, 1-2mm, 2-3mm, 3-4mm, 4-5mm) were 1.07N, 2.18N, 1.00N, 0.26N and 0.15N during the loading period. For the unloading period, the force levels delivered from intervals (5-4mm, 4-3mm, 3-2mm, 2-1mm, 1-0mm) were 0.89N, 0.96N, 0.28N, 0.84N and 0.62N respectively.In Ormco Damon Wires, the force levels delivered from intervals (0-1mm, 1-2mm, 2-3mm, 3-4mm, 4-5mm) were 0.32N, 0.78N, 0.39N, 0.52N and 0.19N during the loading period. For the unloading period, the force levels delivered from intervals (5-4mm, 4-3mm, 3-2mm, 2-1mm, 1-0mm) were 0.33N, 1.86N, 1.39N, 0.49N and 0.16N respectively. Conclusion: Ormco Damon archwires have better and constant force delivery rates and may be suitable for cases with severe crowding and adult dentitions. Galaxy Orthodontics and Captain Ortho have variable force levels and show especially high force delivery during initial delivery. Hence, they are suitable for mild and moderate crowding.