Endodontics · single question
What is the principal reason straight-line access is important in endodontic treatment?
Show answer and explanation
Correct answer: A. It allows instruments to reach the apical third without being deflected, reducing ledging, transportation and separation
- A. CORRECT. STRAIGHT-LINE ACCESS means the instrument can pass from the access cavity to the apical third — or at least to the first canal curvature — without binding on the axial walls. Removing that coronal interference lets the file follow the canal rather than the restoring force of the shank, which is what prevents LEDGING, apical TRANSPORTATION, strip perforation and instrument SEPARATION. It also improves irrigant delivery and exchange.
- B. Sealer is always required to fill the space between the core material and the canal wall, irrespective of access.
- C. Straight-line access necessarily REMOVES tooth structure (the cervical bulge, the mesiobuccal shelf). Conservation is a competing consideration to be balanced against it, not its purpose.
- D. Irrigation remains essential regardless of access design. Better access improves irrigant penetration; it does not replace it.