Tooth cysts and root-end surgery (apicoectomy): does a root canal clear them?

When a tooth's nerve dies from decay, a fracture or a knock, bacteria in the root canal cause inflammation that spreads from the root tip into the bone. The body breaks down bone in that area, which appears dark on an X-ray. Most often this is inflamed tissue called a granuloma; less often a fluid-filled cyst with its own lining develops. X-rays can't always tell the two apart; a definite diagnosis needs the tissue to be examined.

Cysts can also form around impacted teeth, which is one reason impacted wisdom teeth need regular checks. See wisdom teeth.

• Often none at all; it's found on a routine X-ray.
• Tenderness when biting or pressing on the tooth
• A pimple-like bump on the gum, sometimes with a salty discharge. See a pimple on the gum.
• Swelling, pain and fever during flare-ups. See dental abscess.
• Discolouration of the tooth (a sign the nerve may have died)

For most root-tip lesions the first treatment is a root canal: the canals are cleaned, shaped and filled. Once the source of inflammation is gone, the bone gradually repairs itself. If the tooth has already had a root canal, retreatment is considered first.

Healing is followed with X-rays; bone usually fills in over 6–12 months, longer for large lesions. If there are no symptoms and the dark area is shrinking, treatment is on track.

It's used for lesions that don't heal despite a root canal, are very large or can't be reached through the canal. It's done under local anaesthetic:

1. The gum over the root tip is opened.
2. The inflamed tissue or cyst in the bone is removed.
3. A few millimetres of the root tip are cut away.
4. The root end is sealed with a biocompatible filling material that stops bacteria leaking.
5. The gum is stitched; stitches usually come out after 7–10 days.

Removed tissue is sent for pathology when needed. In large cysts a bone graft may be used to help the bone heal.

• Mild swelling and bruising for the first 2–3 days are common; a cold pack helps on the first day.
• Use the painkiller your dentist recommends; antibiotics are given only if needed.
• Don't brush the stitched area for a few days; brush the other teeth as usual.
• Smoking slows healing.
• Bone healing is checked on an X-ray over the following months.

At Dent32 we assess the size of the lesion and whether the tooth can be saved with X-rays and, where needed, a CT scan. See dental X-rays and CT scans. We explain the options — root canal, retreatment, root-end surgery or extraction — in writing, and refer cases that need advanced surgery to the relevant specialty.

Dent32 Ağız ve Diş Sağlığı Polikliniği (Dent32 Dental Polyclinic) is at Barış Mah., Ginza Lavinya, E-5 Yanyolu No:30 D:179, 34520 Beylikdüzü, Istanbul and is open seven days a week. To book, call or WhatsApp +90 555 011 33 68, or use our contact page. At the examination we share the findings, the options and the approximate cost in writing; you are under no obligation to start treatment afterwards.

For clinic details, our dentists and the full list of treatments, visit Dent32, dental polyclinic in Beylikdüzü.