Reciprocating instruments: 86% of 852 papers are laboratory-based, few clinical
A bibliometric analysis of 852 papers on reciprocating kinematics from 2008 to 2026 shows that about 86% of the research is laboratory-based, with a continued lack of clinical studies.
Eighteen years of research, mostly on extracted teeth
Reciprocating motion of NiTi instruments has transformed the mechanical preparation of root canals. A Brazilian team analysed the entire literature on this topic in the Web of Science Core Collection, searched in April 2026 without restrictions on year, language, or number of citations. A total of 852 papers published between 2008 and 2026 were included.
Approximately 86% of the papers were laboratory studies. The most common topic was canal shaping ability and transportation (140 papers). The Journal of Endodontics published the most papers (215), Brazil led in national contribution (231 papers), while Asia was the most productive continent (376). The most cited paper garnered 348 citations, and the paper with the highest citation density averaged 21.11 citations per year. The most prolific author, Silva EJNL, authored 46 papers, indicating how concentrated the field is around a small number of research groups.
The authors also examined the relationship between citations, year of publication, and journal impact factor. The number of citations strongly decreases with more recent publication years (ρ = −0.811), which is expected as newer papers have had less time to be cited. It moderately increases with impact factor (ρ = 0.551), and the impact factor itself slightly decreases over time (ρ = −0.315).
Limitations
Bibliometrics measure quantity and citation, not quality or clinical outcome. The analysis relies on a single database, so works outside it are not covered.
For your practice
- Claims about the safety and efficacy of reciprocating systems mostly originate from laboratories; interpret them as data about the instrument, not treatment outcomes.
- When selecting a system, look for clinical studies with healing follow-up, which are scarce in this literature.
- For planning your own education, canal shaping ability and transportation are the best-researched topics.