Apical Seat
A narrowed, tapered preparation at the apical terminus of the root canal designed to retain the gutta-percha master cone and canal sealer.
Full Definition
The apical seat is a deliberately shaped constriction created at the most apical portion of the prepared root canal, typically 0.5–1.0 mm short of the radiographic apex, to provide a ledge against which obturation materials can be compacted. A well-formed apical seat prevents extrusion of sealer or gutta-percha beyond the apical foramen. Its integrity depends on maintaining canal patency without over-enlarging the apical constriction. Editors will encounter this term in technique descriptions and case report methodology sections. It should not be confused with 'apical stop,' which historically referred to a more abrupt preparation design, now less favoured.
Usage
Usage note: Distinguish from 'apical stop' (older term implying abrupt end-preparation) and 'apical patency' (maintenance of a glide path through the foramen). Two words; do not hyphenate.
In Context
- "A clearly defined apical seat at ISO size 35/0.04 taper was confirmed prior to master cone fitting." — Operative dentistry case report
- "Loss of the apical seat due to over-instrumentation necessitated placement of an apical plug before obturation." — Endodontic procedure note