Abstract

Instrument separation during root canal treatment is a frequent procedural complication particularly with nickel–titanium rotary systems. Although commonly perceived by clinicians as a technical failure requiring immediate correction, the prognostic significance of a separated instrument is primarily determined by biological and anatomical factors rather than by the mere presence of the fragment. This narrative review examines the circumstances under which retrieval is biologically justified and outlines parameters that guide clinical decision-making. Available evidence indicates that in the absence of apical pathology, or when adequate disinfection can be achieved despite the obstruction, a retained fragment does not necessarily compromise long-term outcomes.

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