Ex vivo shaping ability of reciprocating instruments operated by new users: Reciproc versus WaveOne

To compare two reciprocating NiTi systems operated by novices for use in curved root canals.

Fifty mesial roots of extracted mandibular first molars, with 2-2 canal configuration, were scanned with micro-CT and divided into 2 groups according to canal length and curvature: Reciproc and WaveOne. Each system was used to prepare one of the two canals by fourth-year dental students, who were new to reciprocating files and were blinded to the system being used. After another scanning, the pre- and post-instrumentation images were compared 3-dimensionally in software.

Some 43 to 46% of the canal wall area remained un-instrumented. Significantly higher proportions of canals were transported towards the isthmus or furcation aspect than the mesial or external aspect. Mean transported distance was the greatest in the coronal one-third. Remaining dentine wall was the thinnest at the furcal aspect near the middle root region. No significant difference was noted between the two brands in the parameters examined.

Both brands of reciprocating file left similar amounts of un-instrumented canal wall, and resulted in similar extent of canal transportation.

NiTi reciprocating files can safely be used by new users to prepare curved root canals into a predictable shape.