Effect of Saliva on Load-Deflection Characteristics of Superelastic Nickel-Titanium Orthodontic Wires

Objective: most published results about the characteristics of niti wires are based on the mechanical laboratory tests on the as-received wires.the purpose of this study was to investigate the effect of saliva on load-deflection characteristics of superelastic niti wires.materials and methods: in this experimental study, 15 wires of three kinds of superelastic niti wires (sentalloy, force i and truflex) were prepared. five spe-cimens of each wire were tested in the as-received condition (t0) to provide base-line information and the remaining wires were divided into two groups of five. half of them were kept inside artificial saliva for one month (t1), while the oth-ers were kept in air (t2). after 30 days, three-point bending test was done in a dental arch model and data from selected points on the unloading phase of the generated graphs were used for statistical analysis.results: force i and truflex showed significantly greater force than sentalloy. the load values of truflex and force i after one month exposed to artificial saliva (t1) decreased significantly, but sentalloy was not affected significantly. the pla-teau gap values were not considerably different among t0, t1 and t2. conclusion: saliva decreased the load of force i and truflex significantly, but it did not have a statistically significant effect on sentalloy.