Strip perforation in danger zones
What it is
A strip perforation is an oblong/vertical perforation that occurs when instrumentation removes too much dentin from a thin root wall, most classically on the furcal (inner) wall of curved roots — especially the mesial roots of mandibular molars ("danger zone").
Why it happens
• Over-flaring / aggressive coronal–middle enlargement on the furcal (inner) wall where dentin is thin ("danger zone") • Circumferential filing in thin areas instead of directing preparation toward the "safe zone" (thicker outer wall) • Using large tapers/sizes too early, especially in curved canals → files straighten and cut the inner wall • Poor access / lack of straight-line entry → more file deflection and uncontrolled dentin removal (AAE notes perforation/strip perforation as an immediate risk of dentin removal in "danger zones")
The full clinical mistake entry includes
- How to avoid it — the prevention protocol
- The clinical tip experienced clinicians use
- The documented reference behind the mistake
More clinical mistakes
Dentalverse is an educational resource for dental students and dentists. This page is a study reference — it is not medical advice and does not replace clinical judgment. Always follow your institution's protocols and your supervisor's guidance.