Endodontic diagnosis may be tricky, but never skip it! Before you ever open a tooth, you need to know its diagnosis so you can show why you accessed that tooth.

I know, I know, this seems like such a boring part of endo. But let’s face it: it’s SUPER important. This is how you cover your butt and avoid litigation, plus it’s how you make the right treatment decisions for your patients. If you fail to document your diagnosis, you could get into some real legal trouble, and you can leave referring professionals hanging. Let’s break it down.


You Need a Pulpal AND Periapical Endodontic Diagnosis

It’s essential that you always have a pulpal AND a periapical diagnosis for every tooth that you treat – plus this should be documented clearly in the patient’s chart along with your diagnostic tests. The diagnosis sets the stage for how you treat and manage your patient all along the way.

Pulpal Diagnosis & Symptoms of Pulpitis

Let’s go over the different pulpal diagnosis first. This is what your cold test is testing, it’s testing the status of the pulp.

1. The Normal Pulp: Tooth feels cold and heat with no lingering pain.
The tooth has a normal response to cold and heat. It feels the temperature, but then the sensation goes away after a few seconds. A tooth that has a normal pulp could still need a root canal for restorative reasons, like needing a post in order to retain the core. You’ll see this pulpal diagnosis for teeth that need elective endo.

2. Asymptomatic Irreversible Pulpitis: Decay into the pulp, but no pain.
The tooth needs a root canal and still feels temperature, but there is no real pain associated with the hot or cold stimulus. I usually see this in teeth with a large carious lesion that has already reached the nerve. It’s asymptomatic because the patient doesn’t have pain, and it’s irreversible because the bacteria has permanently damaged and exposed the pulp.

3. Symptomatic Irreversible Pulpitis: Exaggerated response to cold or heat.
This diagnosis always means trouble for our patients, who generally are having a ton of pain and walk in as an emergency. It doesn’t always need to be a “hot” tooth, but this type of pulpitis has an exaggerated response to cold or heat. When I do a cold test, and the patient has a stronger response to cold or a lingering response to cold (more than 10-15 seconds), this will be their pulpal diagnosis.

4. Necrotic Pulp: Tooth has no response to cold.
It’s such an easy one to diagnose!

5. Previously Initiated: The tooth has had a root canal started, but it hasn’t been finished.
I see this one when one of my referring dentists starts the endo, gets stuck, and then sends it to me to finish up. Or the patient moved from another state, or they never returned to finish treatment.

6. Previously Treated: Tooth has had a completed root canal.
Note the difference from the Previously Initiated diagnosis, and make sure you distinguish this clearly.

Periapical Diagnosis

The periapical diagnosis comes from your percussion test and your radiograph. This portion of the diagnosis indicates the status of the periapical tissues.

1. Normal Periodontium: Everything’s normal.
The tooth has no pain to percussion, and the apex looks pristine on the radiograph. It has normal alveolar bone, a normal PDL, and an intact lamina dura.

2. Asymptomatic Apical Periodontitis: A periapical radiolucency is visible with no pain to percussion.
I call this “the silent lesion.”

3. Symptomatic Apical Periodontitis: The tooth is tender to percussion.
It may or may not have a periapical radiolucency.

4. Chronic Apical Periodontitis: The tooth has a sinus tract.
Abscess indicates the presence of pus, and chronic means that it’s an infection that has been there for some time. Most of these patients don’t have pain, but they can still be a bit tender to percussion. When I see a sinus tract, the diagnosis of Chronic Apical Periodontitis (CAP) will trump that of Symptomatic Apical Periodontitis (SAP). And don’t forget you can have a sinus tract that drains through the sulcus, too!

5. Acute Apical Abscess: The patient is swollen.
Sometimes they have significant facial swelling, and sometimes it’s a small vestibular swelling, so bear in mind there is a variety of how this can show up. Again, abscess signifies the presence of purulence. Your patient may have little pain or a lot pain with pain to percussion, but the diagnosis of Acute Apical Abscess (AAP) will always trump that of SAP.

Let’s go over some cases

I’ll present three cases with background information and radiograph imaging. From the information you’re provided, what are your pulpal and periapical diagnoses?

Scroll to the bottom of the blog post for the correct answers.

CASE #1: This patient has no response to cold, but does have severe tenderness to percussion. What are your pulpal and periapical diagnoses?

CASE #2: This patient has no pain, but there was a pulp exposure while doing the crown preparation. The tooth responded normal to cold and was slightly tender to percussion. What are your pulpal and periapical diagnoses?

CASE #3: The tooth has no response to cold and no pain to percussion. However, there is a 9mm probing on the disto-buccal. What are your pulpal and periapical diagnoses?

Here are the answers. How did you do?

CASE #1:
Pulpal Diagnosis:
Necrotic Pulp
Periapical Diagnosis: Symptomatic Apical Diagnosis

CASE #2:
Pulpal Diagnosis:
Asymptomatic Irreversible Pulpitis
Periapical Diagnosis: Symptomatic Apical Periodontitis

CASE #3:
Pulpal Diagnosis:
Necrotic Pulp
Periapical Diagnosis: Chronic Apical Periodontitis
Note: This tooth is totally saveable! Don’t get fooled by the amount of bone loss and the probing depth; it’s just a sinus tract draining through the sulcus.

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As always, thanks for stopping by, and don’t forget to give teeth a chance!

My best,


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