Martins J N R, Silva E J, Marques D et al. Influence of Kinematics on the Cyclic Fatigue Resistance of Replicalike and Original Brand Rotary Instruments. J Endod 2020; 8: 1136-1143.

Well known brands tested against look-a-likes.

Instrument separation is a major concern during root canal preparation with rotary NiTi instruments. Stress caused by excessive torsion and cyclical fatigue in curved canals are likely causes. Manufacturers are now staring to produce systems (termed replicalike systems in this paper), similar to the originals produced by well known companies, but which are commonly cheaper.

The results showed that all systems had a significantly higher time to separation in reciprocating mode than in continuous rotation. The replicalike systems also showed a significantly longer time to separation than the original instruments, in both reciprocation and continuous rotation. There was no significant difference between the sizes of the fractured segments. Using energy dispersive spectroscopy, all tested instruments showed an identical ratio between nickel and titanium.

However, there are no international standards to guide the production of, and impose standards on, manufacture of NiTi instruments. Therefore, clinicians may be unaware of the potential risks taken in using replicalike systems.