How an Apicoectomy Actually Works, From the Surgeon's Chair

The word apicoectomy sounds dramatic. Most patients picture something far more invasive than it actually is. So let's walk through what happens, step by step, from the surgeon's perspective — based on the foundational protocol published by Syngcuk Kim and Samuel Kratchman in the Journal of Endodontics, which has been the reference for endodontic microsurgery teaching worldwide for two decades.¹

What an Apicoectomy Is — and Isn't

A modern apicoectomy is a small surgical procedure to clean and seal the very tip of a tooth's root from the outside. It's used when a previous root canal hasn't fully resolved an infection and conventional retreatment through the crown isn't an option (for example, when there's a post in the canal that can't be safely removed, or when a crown is in good condition and shouldn't be disturbed).

It is not the apicoectomy of 30 years ago. The procedure has been transformed by three changes that happened together: the surgical operating microscope, ultrasonic tips small enough to fit inside a millimeter, and biocompatible filling materials that form a true biological seal.¹ The combination is what the literature now calls endodontic microsurgery, and it succeeds in roughly 94% of cases — versus about 59% with the older techniques.²

Before the Day: Planning

The most important part of an apicoectomy happens before any incision is made. At your consultation, we take a 3D cone-beam (CBCT) scan of the tooth and surrounding bone. This shows the exact shape of the lesion, the position of the root tip relative to nearby structures (the maxillary sinus on upper molars, the inferior alveolar nerve on lower molars), and any anatomy that might surprise a surgeon working from 2D X-rays alone.

The CBCT lets us measure exactly how much bone we'll need to remove, choose the right angle for the osteotomy, and plan the filling material. It's the difference between operating with a map and operating from memory.

The Day of Surgery: A 60–90 Minute Visit

The procedure is done in our office under local anesthesia — the same kind used for a filling. Most patients drive themselves home afterward.

Step 1: Anesthesia (5–10 minutes)

We numb the area thoroughly. For an upper tooth, this is a single injection. For a lower molar, it's a nerve block similar to what you'd receive for a wisdom-tooth extraction. You feel pressure and movement during the procedure, but no sharp pain.

Step 2: Flap (5 minutes)

A small incision is made along the gumline near the affected tooth. The gum is gently lifted away from the bone — like turning back the corner of a page. The microscope is essential here: the incision and the flap are designed to heal almost invisibly, with sutures so fine (5-0 or 6-0 monofilament) that most patients can't feel them with their tongue.

Step 3: Osteotomy — the Window in the Bone (5–10 minutes)

A small opening — typically 3–4 millimeters across, about the size of a grain of rice — is made through the bone over the root tip. In traditional surgery, this opening was much larger because the surgeon couldn't see well enough to work in a small one. The microscope changes that. Less bone removal means faster healing, less swelling, and a smaller scar in the bone that fills back in completely within a year.

Step 4: Apicectomy — Cutting the Root Tip (5 minutes)

The very last 3 millimeters of the root tip are removed. There is a specific reason for this number: research has shown that the vast majority of accessory canals, lateral branches, and complex anatomy that a root canal can't reach is concentrated in the apical 3 mm.¹ Removing this section eliminates the source of the persistent infection.

The cut is made nearly perpendicular to the long axis of the root — about 0–10 degrees of bevel — rather than the steep 45-degree angle used in traditional surgery. The shallower angle preserves more tooth length and exposes fewer dentinal tubules (the microscopic channels through which bacteria can re-enter), giving the seal a better chance to last.¹

Step 5: Inspection Under High Magnification (5–10 minutes)

This is the step that the microscope makes possible and that the older techniques simply could not perform. The freshly cut surface is examined at 16× to 25× magnification with micromirrors — angled mirrors smaller than a pencil eraser. Under that level of detail, the surgeon can identify:

• Isthmuses — narrow ribbon-like connections between canals that are invisible at lower magnification
• Accessory canals — small side branches that diverge from the main canal
• Microfractures — hairline cracks that may be the real reason the tooth has not healed
• Missed canals — entirely separate canals that the original root canal never found

Each of these can be the source of the persistent infection. None of them can be cleaned without first being seen.

Step 6: Ultrasonic Root-End Preparation (5–10 minutes)

A diamond-coated ultrasonic tip — about a third of a millimeter wide — is used to clean a small cavity, 3 mm deep, into the cut surface of the root. The cavity follows the natural shape of the canal anatomy, including any isthmus connecting two canals. This is something a traditional bur, which only cuts in one direction, simply cannot do.

Step 7: Root-End Filling (5–10 minutes)

The cleaned cavity is filled with mineral trioxide aggregate (MTA) or a similar bioceramic material. Unlike the amalgam used in traditional apicoectomies, MTA is biocompatible — the surrounding bone treats it not as a foreign material to wall off, but as a surface to grow against. The result is a true biological seal.

Step 8: Closing (5 minutes)

The flap is repositioned and held in place with very fine sutures. Most patients describe the closure as feeling like nothing more than gentle pressure on the gum.

After the Surgery

You leave with detailed written instructions, an ice pack, and a phone number to reach Dr. Kung directly if anything feels off. Most patients take ibuprofen for the first 24 hours and are back to normal eating, working, and exercising within 1–2 days. Sutures are removed at a brief follow-up visit a few days later.

We schedule a follow-up X-ray at 6 months and a final one at 12 months to confirm bone regeneration. In a successful case — which the literature puts at about 94% of properly performed microsurgical procedures — the dark area on the X-ray that represented the original infection has been replaced by healthy bone, and the tooth is fully retained.²

What This Used to Look Like — and Why It's Different Now

For most of the 20th century, this same procedure looked very different. The opening through the bone was several times larger. The root cut was at a 45-degree angle, exposing many more dentinal tubules. The filling was amalgam, which doesn't biologically integrate. There was no microscope, no isthmus inspection, no ultrasonic preparation. The success rate, across decades of published studies covering 925 cases, was 59%.²

The procedure performed today, with the same goals but very different tools, succeeds in 94% of cases.² When you choose a specialist endodontist, you are choosing the second protocol. The difference is real, it's been measured, and it determines whether your tooth is still in your mouth ten years from now.

Questions?

If you've been referred for an apicoectomy and want to talk through what to expect for your specific tooth — or if you'd just like a second opinion before committing to surgery — we offer in-person and virtual consultations. Schedule a consultation or call (669) 234-2354.

References
1. Kim S, Kratchman S. Modern endodontic surgery concepts and practice: a review. Journal of Endodontics 2006;32(7):601–623.
2. Setzer FC, Shah SB, Kohli MR, Karabucak B, Kim S. Outcome of endodontic surgery: a meta-analysis of the literature — Part 1: Comparison of traditional root-end surgery and endodontic microsurgery. Journal of Endodontics 2010;36(11):1757–1765.