Mechanical properties of aesthetic nickel-titanium wires before and after clinical use

The objective of the study was to compare the mechanical properties of aesthetic orthodontic Ni-Ti wires before and after clinical use. . The experimental group consisted of 75 0.014" coated Ni-Ti wires — 15 from each of the 5 companies selected, namely Group I — D-tec, Group II — JJ Orthodontics, Group III — OSL, Group IV — American Orthodontics, and Group V — Koden. The control group consisted of two groups with 25 coated 0.014" Ni-Ti, 5 from each company (without clinical use) and 25 non-coated 0.014" Ni-Ti 5 from each company (without clinical use). The experimental wires were retrieved from the patient’s mouth after one month and tested in the laboratory, for their mechanical properties which included: load deflection, flexural modulus, and microhardness. . Mean micro-hardness of experimental samples is significantly lower in Group III (303.9±8.9; p=0.001). The mean micro-hardness of coated control samples is significantly lower in Group I (309.8±18.2; p=0.674). In Groups I, II, IV and V, the mean micro-hardness of experimental, coated and non-coated control samples was not statistically significant. . On comparison of mechanical properties like load deflection, flexural modulus, and hardness of aesthetic orthodontic Ni-Ti wires, it was observed that there was a significant difference among five different types of Ni-Ti wire. Also, difference was observed among the experimental group, the coated control group and the non-coated control group. A significant difference was seen in Ni-Ti wire before and after clinical use.