TY - JOUR
TI - Mechanical properties of orthodontic wires derived by instrumented indentation testing (IIT) according to ISO 14577
AU - Zinelis, S.
AU - Al Jabbari, Y.S.
AU - Gaintantzopoulou, M.
AU - Eliades, G.
AU - Eliades, T.
JO - Progress in Orthodontics
PY - 2015
VL - 16
TODO - 1
SP - null
PB - Springer Berlin Heidelberg
SN - 2196-1042, 1723-7785
TODO - 10.1186/s40510-015-0091-z
TODO - molybdenum;  stainless steel;  titanium;  alloy;  dental alloy;  nickel;  titanium molybdenum alloy;  titanium nickelide, Article;  elasticity;  indentation modulus;  instrumented indentation testing;  Martens hardness;  materials testing;  mechanics;  orthodontic wire;  physical parameters;  priority journal;  residual stress;  Vickers hardness;  algorithm;  chemistry;  comparative study;  hardness;  human;  materials testing;  mechanical stress;  mechanics;  surface property;  Young modulus, Algorithms;  Alloys;  Dental Alloys;  Elastic Modulus;  Elasticity;  Hardness;  Humans;  Materials Testing;  Mechanical Phenomena;  Nickel;  Orthodontic Wires;  Stainless Steel;  Stress, Mechanical;  Surface Properties;  Titanium
TODO - Background: The aim of this study was the characterization of mechanical properties of representative types of orthodontic wires employing instrumented indentation testing (IIT) according to ISO 14577. Methods: Segments were cut from ten wires. The first six are made of stainless steel (SS), two are made of Ni-Ti, and the last two are made of titanium molybdenum alloys (TMA). Then, the Martens hardness (HM), the Vickers hardness (HVIT) based on indentation hardness (HIT), the indentation modulus (EIT), the ratio of elastic to total work (ηIT), and the traditional Vickers hardness (HV1) were measured by IIT. The results were statistically analyzed by one-way ANOVA followed by Student-Newman-Keuls (SNK) test at a = 0.05. The HVIT and HV1 data were analyzed by paired t test (a = 0.05). Results: SS wires showed the highest hardness followed by TMA and Ni-Ti alloys. However, all wires showed significantly lower HVIT compared to corresponding HV1, a finding probably appended to elastic recovery around the indentation. EIT for all wires tested was determined much lower than the nominal values of the corresponding alloys due to the implication of residual stress field at the slope of unloading curve. Elastic to total work ratio was ranged from 45.8 to 64.4 % which is higher than that expected for ductile alloys (<30 %). Conclusions: The products tested illustrated significant differences in their mechanical properties. Although IIT provides reliable data for hardness and elastic index of materials tested, the intense residual stress field developed during the manufacturing process significantly affects the determination of modulus of elasticity. © 2015, Zinelis et al.
ER -