Mechanical characteristics of counterfeit Reciproc instruments: a call for attention

Abstract

Aim

To report here the main differences between the visual aspects of original and counterfeit Reciproc instruments, together with an evaluation of instrument bending resistance, cyclic fatigue, surface finish, Vickers microhardness, and chemical composition.

Methodology

The visual aspects of original Reciproc R25 (VDW, Munich, Germany) and counterfeit Reciproc R25 instruments (claimed to be original, supposedly with dimensions similar to those of Reciproc R25 files, bought at http://ift.tt/HuxBab) were evaluated under direct observation, stereomicroscopy and scanning electron microscope. The flexibility of original and counterfeit Reciproc R25 was determined via 45° bending tests according to the ISO 3630-1 specification. Instruments were also subjected to cyclic fatigue resistance, measuring the time to fracture in an artificial stainless-steel canal with a 60° angle and 5-mm radius of curvature. The fracture surfaces of all fragments were examined under a scanning electron microscope. Roughness of working parts was quantified using a profilometer, and the microhardness test was carried out using a Vickers hardness tester. Energy-dispersive X-ray microanalysis (EDX) were also carried out. Results were statistically analyzed using a student′s t-test at a significance level of P < 0.05.

Results

Although the packaging of the original and counterfeit instruments was similar, a number of differences were observed regarding the visual aspect such as ISO colour coding, lines of measurement, stopper and morphologic characteristics. Original Reciproc instruments had significantly longer cyclic fatigue life and significantly lower bending resistance than counterfeit Reciproc instruments (P < 0.05), as well as significantly lower microhardness and lower roughness (P < 0.05). EDX results revealed differences in the chemical composition of the instruments (P<0.05), indicating that the instruments were manufactured with different raw material.

Conclusion

Original Reciproc files outperformed counterfeit instruments in all tests. It is thus important that identification strategies for these counterfeit instruments be developed, thereby preventing their inadvertent use.

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