Crown-Down Technique
A root canal preparation strategy in which canal instrumentation begins coronally and progresses apically, reducing the microbial load and debris burden before the apical region is instrumented.
Full Definition
The crown-down technique (also called step-down or coronal-to-apical preparation) was introduced as an alternative to the step-back approach to reduce apical extrusion of debris, improve irrigant penetration, and maintain canal shape. Preparation proceeds from larger instruments in the coronal third to progressively smaller instruments at the apex. This sequencing is foundational to most modern rotary nickel-titanium systems. Editors should note that 'crown-down' is hyphenated as a compound modifier before a noun (e.g., 'crown-down sequence') but may stand alone as a noun phrase ('the crown-down technique'); consistency must be maintained throughout a manuscript.
Usage
Usage note: Hyphenate when used as a compound modifier ('crown-down sequence'). Do not capitalise unless at the start of a sentence.
In Context
- "Canal preparation was completed using a crown-down technique with a reciprocating single-file system." — Materials and Methods — RCT
- "The crown-down approach significantly reduces apical extrusion of debris compared with step-back instrumentation." — Literature review