Broken File — Curved Canal

Why this case matters

File separation in a curved canal is clinically the hardest retrieval scenario. The fragment often sits exactly where curvature peaks, removing most tolerance for error.

Training outcomes

• Curved canal retrieval strategy
• Risk assessment before and after separation
• Bypass in angulated anatomy

Common mistakes this model helps you avoid

• Attempting rotary retrieval inside a curve
• Over-enlarging the outer curve and thinning the canal wall
• Skipping CBCT when available
• Pushing the fragment apically while probing

Suggested training protocol

1. CBCT (when available) to map fragment relative to curvature
2. Straight-line access exaggerated to the coronal third
3. Microsurgical ultrasonic tip under magnification
4. Bypass with ultra-flex pre-curved 08 file
5. Reassess every 2 minutes; stop if thinning is suspected

What a successful exercise looks like

• Either clean retrieval or safe bypass preserving wall thickness
• Working length restored
• No strip perforation on the danger zone