Impact of conservative versus conventional instrumentation on the release of inflammatory mediators and post-operative pain in mandibular molars with asymptomatic irreversible pulpitis: A randomized clinical trial
Sıla Nur Usta, Ana Arias, Emre Avcı, Emmanuel João Nogueira Leal Silva
First published: 14 March 2025 https://doi.org/10.1111/iej.14224
A Study in the Bleeding Obvious: A Critical Review of the Study on Inflammatory Mediator Release After Root Canal Preparation
For those in the endodontic community patiently awaiting the next groundbreaking revelation in post-operative pain management, this paper… is not it. What we have instead is a labour-intensive investigation into what amounts to common clinical sense: that mechanical instrumentation might irritate periapical tissues and transiently elevate inflammatory markers — and, gasp — possibly lead to some temporary discomfort. The authors set out to compare post-op pain and inflammatory mediator levels following root canal preparation with three different file systems. What they found is that all groups had increased mediators and pain at 24 hours, followed by a return toward baseline at 72 hours — a pattern as surprising as gravity.
The core hypothesis — that minuscule differences in taper or cross-section between file systems would somehow produce clinically meaningful variation in post-operative pain or cytokine profiles — stretches plausibility. Pain is, of course, a notoriously multifactorial phenomenon influenced by individual pain thresholds, procedural variables, and host response. Yet this study attempts to reduce it to a matter of which rotary NiTi file happens to be used. Moreover, the authors seem to place undue weight on gingival crevicular fluid analysis, which, while non-invasive, is not a particularly robust surrogate for periapical inflammation, especially in vital teeth. More clinically meaningful endpoints, such as healing rates or success at 6 and 12 months, were not even considered. One might reasonably ask: would it not have been more informative to compare outcomes with and without obturation, or across different sealer chemistries? That might have offered insight into something beyond a fleeting blip on the VAS scale.
As for the statistical pyrotechnics — including odds ratios for changes in mediator levels that reach double digits — they appear more dazzling than relevant. When nearly every difference disappears by 72 hours and analgesic use is uniformly low, one is left wondering what exactly the point was. The conclusion that conservative instrumentation “reduced inflammatory mediators” but did not impact post-op pain reads like an apology for failing to show anything meaningful. Perhaps most troubling is the absence of clinical consequence: patients were asymptomatic pre-op, had mild transient pain post-op, and all went on with their lives regardless of the instrument used. In the end, this elaborate exercise confirms what clinicians already knew — that a file’s brand name is not the central determinant of post-operative pain. A lot of brain cells and paper points sacrificed to tell us what every experienced operator could have predicted.
