Background and aims. This experimental study mainly aims at comparing the most important mechanical properties of the new orthodontic archwires, those immersed in fluorinated solution, the as-retrieved ones and  the intra-oral used ones.

Methods. A total of 270 arch wires were tested, using tensile testing and three-point bending tests. The tested archwires were made of Stainless Steel, Nickel Titanium, Beta-Titanium and physiognomic covered Nickel Titanium. The tested archwires were subjected to three types of treatments: immersion into fluorinated solution, immersion into carbonated drinks and intra-oral use.

Results. The immersion caused variations of the activation and deactivation forces of all arch wires. The most affected arch wires, in terms of bending characteristics,  were the intra-oral used ones.

Conclusions. The alteration of mechanical properties of the orthodontic arch wires by their immersion into fluorinated solutions and soft drinks could not be statistically demonstrated.


orthodontic archwires, nickel titanium, stainless steel, beta-titanium, mechanical testing