Reciprocating instrumentation in endodontics: 14,233 teeth and the paradigm of technique-dependent success

A large-scale retrospective study covering 14,233 teeth demonstrated a significant advantage of reciprocating instrumentation over manual and rotational methods of root canal treatment regarding long-term tooth preservation. Despite significant progress in endodontics, data on the impact of modern treatment protocols on long-term outcomes remain limited.

For his study, Dr. Ahmed Elmaasarawi, an endodontist with 20 years of experience, analyzed three endodontic treatment protocols used over 25 years in the clinic of the Academy for Continuing Education in Dentistry in Karlsruhe, Germany.

Compared endodontic treatment protocols

The first protocol (1999–2007, 5,450 teeth) involved the use of manual K-files, conventional sodium hypochlorite irrigation, radiographic determination of working length, and obturation by lateral condensation using AH Plus sealer.

The second protocol (from 2008, 1,667 teeth) included rotary instruments (RaCe and BioRaCe) after preliminary glide path preparation with manual files; irrigation using sodium hypochlorite and citric acid; passive ultrasonic irrigation; electronic determination of working length, and identical obturation.

The third protocol (from 2011, 7,116 teeth) employed reciprocating Reciproc instruments without preliminary glide path preparation; passive ultrasonic irrigation and electronic determination of working length. Subsequently, there was a transition to bioceramic sealers and warm vertical condensation.

Key study results

The third protocol demonstrated a significantly higher level of tooth preservation. Over a 10-year period, survival rate was approximately 68% compared to lower rates in the two previous groups. Compared with the manual technique, the use of Reciproc reduced the need for non-surgical retreatment by 66% and surgical intervention by 57%. Overall reduction in the need for retreatment reached 30–40%.

Interpretation of success and clinical conclusions

The analysis revealed that the improvement in outcomes was mainly due to the instrument, rather than the irrigation system or obturation technique. The authors noted that reciprocating instruments require work with a single file instead of a sequence of instruments, which accelerates the procedure and makes it more accessible to practicing clinicians with less experience.

An unexpected finding was the absence of clinician experience’s influence on treatment outcome — the improvement in endodontic treatment methodology made it possible to achieve good results regardless of specialist qualification. However, it was found that patient age affected the prognosis: elderly patients demonstrated less favorable outcomes, which requires special attention during treatment and educational work regarding the importance of regular monitoring.

The study was published in the October issue of International Endodontic Journal for 2025.

Source

Original publication