Once you've decided to save a failed root canal, one question remains: which door? Retreatment enters from above, redoing the canal work; the apicoectomy enters from below, surgically sealing the root tip. They fix the same failure from opposite ends — and the choice follows the anatomy.
| RETREATMENT (ABOVE) | APICOECTOMY (BELOW) | |
|---|---|---|
| Route | Through the crown, down the canals | Small gum window at the root tip (~3mm removed) |
| Fixes best | Missed canals (MB2 missed in up to 90% without microscope), leakage, old material, recontamination | Root-tip cysts, blocked canals, persistent apex infection, complex apical anatomy |
| Blocked by | Impassable posts or calcification | Anatomy near nerves/sinus (rarely) |
| Cost | $1,500–$2,500 | $800–$1,500 |
| Visits | 1–2 | 1 |
| Recovery | Like a root canal — 1–2 days | 2–3 days of mild swelling, 1–2 weeks surgical healing |
| Success | 75–85% | 90%+ (microsurgical, with ultrasonic preparation and bioceramic materials) |
The default order, and why.
When both doors are open, retreatment usually comes first: the most common failure causes — missed anatomy and leakage — live in the canal system, where only retreatment can reach them. If the original treatment missed a canal, an apicoectomy (which only treats the root tip) won’t fix that — the missed canal will continue to harbor bacteria.
Surgery shines when the canal route is blocked (a large post you’d destroy the tooth removing, or a bridge where removing the restoration would damage adjacent teeth) or when a well-treated canal still has disease walled off at the apex. Sometimes the honest sequence is both: retreat, wait six to twelve months, and reserve surgery for a stubborn apex.
The combined path — retreatment ($1,500–$2,500) plus apicoectomy ($800–$1,500) if needed — is still significantly less than extraction plus implant ($4,000–$6,000+), keeps your natural tooth, and has a very high combined success rate.
"The anatomy chooses the door. Our job is to read the anatomy honestly."
And occasionally the answer is a third door entirely: for teeth where neither route works, intentional reimplantation — repairing the tooth outside the mouth and returning it — has saved cases everyone else had closed the book on.
Canal-level causes (missed anatomy, leakage): retreat from above. Apex-level disease or a blocked canal: microsurgery from below. Both run 75–90%+ in specialist hands.
The CBCT reads which failure yours is — the choice should never be made without it.