Let’s talk diagnosis. I’ve got pulpal and periapical diagnosis on the brain after revisiting a few cases that really made me examine the importance of getting the right endodontic diagnosis along with clear documentation, and proactively communicating with our patients.

An endodontic diagnosis may be tricky—but that isn’t an excuse to skip it! Before you ever open a tooth, you need to know its diagnosis, so you can explain why you accessed the tooth to begin with. Point blank. Period. 

I know what you’re thinking. “Sonia, this is such a borrring part of endo.” But it’s totally at the heart of what we do—and it’s straight up how you cover your butt and avoid litigation later on. Not to mention (and most importantly!), an accurate diagnosis leads to the right treatment decisions for your patients!

From diagnosis to documentation—this stuff is so important to avoid legal trouble, support specialists you refer out to, and give your patients A+ care. 

Let’s get into it.

Pulpal and Periapical Diagnosis: Start Here

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 and make sure all their teeth remain healthy. 

I like to start by nailing down my pulpal diagnosis. 

So, let’s examine the symptoms in more detail, shall we? 

Pulpal diagnosis is essentially what your cold test is testing for—it’s helping you get a sense of the status of the pulp. Do not skip this step. It is SO very important.

1. 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 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.

This is a real 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. This also happens when the patient moved from another location, 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.

Phase one complete! But we need a pulpal AND a periapical diagnosis, so our work isn’t done yet. 

On to the Periapical Diagnosis!

The periapical diagnosis comes from your percussion test (or your bite test) and your radiograph. 

The percussion test and radiograph are every bit as important as the cold test is for a pulpal diagnosis. Make sure you do all of them–yes, all of them! 

Here are your options when it comes to diagnosis: 

1. Normal Periodontium: Everything’s normal.

We love to see some normal periodontium! Here, the tooth will have 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.” It’s not great, but at least the patient isn’t experiencing lots of pain. 

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.

The abscess indicates the presence of pus, and the “chronic” part 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! This stuff is tricky, so pay attention.

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 are a variety of ways this can show up. Again, the abscess signifies the presence of purulence. Your patient may have little pain or a lot of pain when it comes to percussion, but the diagnosis of Acute Apical Abscess (AAP) will always trump that of SAP.

Let’s get eyes on a few cases

Let’s look at three cases. I’ll provide some background information and then radiograph imaging.

Here’s your task: From the information provided, what are your pulpal and periapical diagnoses?

Don’t worry, I won’t hold out on you—just 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 normally 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?

Let’s see how you scored!

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.

How’d you do?!

Endo diagnosis isn’t easy stuff, so don’t be hard on yourself if you didn’t come up with the correct answer in every case. 

I hope this post has made you feel more confident in your diagnostic skills, so you can better understand and explain to your patients their pulpal and periapical diagnoses and come up with the right treatment plan together. 

If you want to nail your diagnoses going forward, why not check out my award-winning online endodontic CE course, E-School: Everyday Endo Made Easy? It’s all about doing better endo, from diagnosis all the way to the final obturation. 

And if you’d like a little more support right this minute—grab my free diagnostic checklist, print it out, and put it to good use starting today!

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

My best,


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