Impact of Retained Separated Instruments on Root Canal Treatment Outcome
When an instrument separates in a root canal system, 2 main concerns need to be addressed to maximize the long-term treatment outcome.
The first is the existence of a metal fragment inside the tooth and the possibility of corrosion.
The other main concern is that a separated instrument usually hinders or blocks access to the apical canal terminus and thus compromises the effectiveness of cleaning and shaping procedures, which may affect the treatment outcome.
Management of separated instruments includes orthograde or surgical approaches. Orthograde approaches are as follows :
- attempts to remove the fragment,
- attempts to bypass the fragment, or
- cleaning/shaping and filling of the root canal to the level of the fragment.
In general, it would seem appropriate that the optimum management option was removal of the fragment so that cleaning and shaping of the root canal system could be completed effectively to eliminate microorganisms. Such an approach is usually recommended, in particular when the tooth is strategically important and tooth retention is critical.
However, removal of a separated instrument is a sophisticated process that requires training, experience, and knowledge of the methods, techniques, and devices that can be used. Indeed, attempts to remove separated instruments are influenced by several factors and can be associated with complications that may jeopardize the prognosis of the tooth.
In light of these factors, limitations, and possible complications, management of separated instruments must be a systematic yet dynamic process, with the clinician constantly reassessing progress and considering alternative treatment options when necessary.