Periapical Abscess With Sinus VS Without Sinus

Written & Reviewed by Dr David Chen

The difference between a periapical abscess with sinus vs one without sinus, is that the former is a progression of the latter. That means they are on the same spectrum for the same oral condition.

Therefore, you can gauge how far along you are with your tooth abscess depending on whether or not a sinus tract is present in your mouth.

With sinus vs Without sinus

In a nutshell, a periapical abscess without a sinus is the predecessor or precursor to a periapical abscess with a sinus. They are the same type of infection, it’s just that the without a sinus form is an earlier stage than the form with a sinus.

Periapical abscess with sinus
Periapical abscess with sinus

Stages of a periapical abscess:

  1. Periapical abscess without sinus.
  2. Periapical abscess with sinus.
  3. Gum boil formation.

Essentially, they’re both on the same spectrum for the same oral disease. One of them is the more severe or advanced version of the other which can occur when the condition is left untreated.

Comparison table

Below is a comparison table showing you the differences in signs and symptoms for each of these stages of the same abscess.

TraitsWith SinusWithout Sinus
AppearanceGum boilNo gum boil
PainMaybe painfulLikely painful
ExudatePusNo pus
Infection originRoot tipRoot tip
RadiographicLarge radiolucencyLarge radiolucency
Tooth vitalityNecroticNecrotic
Periapical abscess without sinus vs with sinus

We wish to reiterate that the with sinus form of a periapical abscess is simply an advanced progression of the without sinus.

Periapical abscess with sinus

A periapical abscess with a sinus tract is a tooth abscess in the later stages.

The infection has progressed enough that it has carved a tunnel through the jaw bone from the root tip to the surface of the gums, thus forming a pimple on the gums.

  • The carved out tunnel is the infection destroying the jaw bone by hollowing it out. This hollowed out pathway is what is known as a sinus tract.
  • The pimple on the gums is merely orifice or opening of a sinus tract.

Basically, the sinus tract is a pathway that connects the abscess from the tooth root tip in the jaw bone to the gums in the mouth.

Signs & symptoms

The most distinctive trait for this condition is the presence of a sinus tract.

  • Pimple on the gums.
  • Pus that oozes out of the boil.
  • May or may not be painful.
  • Shows up as a big dark radiolucency on PA x-rays.
  • Tooth is dead.
x-ray of tooth with halo around root after root canal - outlined

The x-ray above shows a molar with a periapical abscess that was treated with endodontic therapy (root canal).


Treatment for a periapical abscess that has a sinus tract will need a root canal along with antibiotic placement inside of the canals. It will be a multi visit procedure.

What to expect:

  1. You will be thoroughly numb for all visits.
  2. Root canal will be started on the tooth.
  3. Nerve will be removed and the interiors of the canals will be disinfected.
  4. An antibiotic paste will be placed inside of the canals.
  5. Temporary restoration placed.
  6. Wait 1-2 weeks for antibiotics to get rid of the sinus.
  7. If the sinus tract doesn’t go away, your dentist may need to do another round of the antibiotics.
  8. Once the gum boil resolves, your dentist can fill in the root canal.

Periapical abscess without sinus

A periapical abscess without a sinus tract is a tooth abscess in the beginning stages.

The tooth infection has just begun and it hasn’t caused enough damage to form a sinus tract which is why it doesn’t have one. As of the moment, the abscess is localized to just the tip of the infected tooth root.

However, if you leave this condition untreated it will progress and eventually develop a sinus tract and also a gum boil.

Signs & symptoms

Often times, most patients don’t know that they even have this condition because there are no oral manifestations. The sinus tract is not present so the chances of you knowing you have this are quite slim.

  • No pimple on the gums.
  • No purulence present since there is no sinus tract.
  • May or may not be painful.
  • Tooth is non-vital.
  • Often has a large radiolucent lesion on PA x-ray.
Front tooth after root canal x-ray
Periapical abscess without sinus that has been root canal treated

The x-ray above shows an upper front lateral incisor that had a periapical abscess but without a sinus tract present. It has been successfully treated with a root canal.


The treatment for a tooth with a periapical abscess and without a sinus is the same as one with a sinus tract present. It will be a multi visit endodontic appointment where antibiotics will still be required.

What to expect:

  1. Expect to be numb for all of the visits.
  2. Root canal will be initiated on the tooth.
  3. Infected nerve will be removed and the canals will be disinfected.
  4. An intracanal antibiotic paste will be placed.
  5. Temporary restoration placed.
  6. Wait 1-2 weeks for the antibiotics to kill the abscess.
  7. Once the tooth is free of bacteria and infection, your dentist can fill the canals and complete the procedure.

The Verdict

Both a periapical abscess without a sinus and one with a sinus are the same type of infection. It’s just that one of them is the more advanced form of the other when it is left untreated and allowed to progress.

The main differentiating factor between how the two look is that the one with a sinus will often have a pimple on the gums.

Treatment for both of these two stages of a dental abscess are the same. They will require root canals and also intracanal antibiotics to rid the tooth of the infection.


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