Stop “Dropping” Into the Chamber During Your Molar Endo Access

I’m not new to teaching endodontics at this point. Something I’ve come to realize after teaching at my local dental residency and training E-School dentists is that endo access—in particular, molar endo access—is something a lot of dentists struggle with. And it’s probably one of the most important steps during the root canal process. And worst of all… a lot of dentists don’t even realize they’re struggling with access! So if you’re a dentist, period, this post is for you.

You may think that instrumenting is your hardest step. And without question, it can be tricky. But if your access is off, it will make your instrumentation even harder. That’s why it’s important to know the shape that your access should be, and where that access should be, within the occlusal table. 

Take it from me: When your molar endo access is off, it can make finding your canals a struggle. Why? Because you lose all of your landmarks, making straight-line access more difficult and leading to mishaps like file separation during your instrumentation.

Can you see how one step will impact the next? It’s like a terrible game of dental dominoes.

I will talk more about access shape and anatomy in another blog, but for today, I want to talk about something that I see dentists do often that needs a little attention. I love teaching endodontic tips, but this “trick” is one that you need to approach with caution. 

Stop Doing This Molar Endo Access “Trick”

Are you one of those people who accesses a tooth and waits for the handpiece to “drop” to give you your cue that you’re in the chamber?

I’ve definitely heard of this trick being used and being taught.

But when I teach molar endo access to my students, I really don’t like them relying on this method… unless they’re paying super-close attention to their radiographs. You can get yourself (and your patient) in some deep doo doo if that feeling of the “drop” is the only gauge you use to know whether you’ve accessed the tooth chamber.

You know me, I love tooth stories! So let me share with you a few radiographs that help explain what I mean.

Molar Endo Access Case #1: A “Safe” Tooth Story to Start

Let’s look at this first example. If you look at the chambers of this patient’s teeth, you can see that they’re huge. These are some wide open spaces!

I just happened to be doing a root canal on tooth #19 on this patient, but I would think this rule could apply to any one of his molars, since he has very long and open chambers. In a case like this, you’ll most definitely feel the “drop,” and I think it’s pretty safe to do so. Just make sure that when you’re deciding how to go about your molar endo access, you’re making that judgment from the bitewing radiograph—and not the periapical radiograph. The bitewing will be more accurate!

Molar Endo Access Case #2: A More Calcified Tooth

Let’s move on to another case. This patient still has a chamber inside their tooth, but that chamber is a little more calcified than the previous case. It’s still a good chamber and is by no means TOTALLY calcified, but it’s not as open as Case #1.

When going about your molar endo access in this situation, you could probably get away with feeling for the “drop” into the chamber, but you’re starting to get into a danger zone. It’s just not as simple, straightforward, and safe as Case #1.

This is where I would start depending more on my Endo Explorer than the feel of my bur. 

Here’s my strategy: When cases start to get like this, I like to drill a little bit, have a peek to see where I am, then poke with my Endo Explorer. If I can’t poke into the chamber, I drill a little bit more, have another peek… I think you get the idea.

For this patient, I was focusing on tooth #14. Do you notice just how much that crown gets in the way of this assessment from the periapical view? The bitewing is a much better image to make this assessment with.

Molar Endo Access Case #3: Coronal Calcification Everywhere

Now, let’s crank that calcification WAY up!

No matter which way you look at tooth #30, it has a lot of coronal calcification. The straight angle shows it, the off-angle shows it, and the bitewing shows it. It’s there with a vengeance, and there ain’t no way around it!

If you depended on that feeling of “dropping” into the chamber during this particular molar endo access, you can guarantee that you’d be “dropping” into the furcation, because a chamber like this just will not give you that “dropping” sensation.

You’re not going to like that, and your patient isn’t going to like that. Not one little bit.

Every Tooth is Different, So Approach Access With Care

What you need to understand—and what I teach my students in E-School—is that every single tooth is completely unique and can have varying degrees of calcification in the chamber. So a one-size-fits-all approach to your access, such as waiting for that “dropping” sensation, just isn’t always going to work. Sometimes you’re going to do some damage that way, and it can lead to all kinds of problems.

But knowledge without action doesn’t mean much, so let’s talk about what you’re going to do from here, now that you know this little molar endo access “trick” isn’t all it’s cracked up to be.

My number one tip for you today is to take a good look at your tooth and how much calcification there is before you start. That way you can know what to expect to feel as you begin accessing the canal. 

This is why I like strong magnification (seriously, don’t skimp out here! I use 5.0 or higher) for good visualization. It’s my crutch when it comes to access preparation. This is the only way to be consistent with getting good at your access and making the process efficient.

I also advise that you use your Endo Explorer to guide you. This will help you find your path into the chamber and then into the canals from there. 

Let’s back up for a second, though, because in reality, judging the level of calcification is actually just one part of the bigger picture—which is the importance of doing good risk assessment in your practice.

It All Starts With Good Risk Assessment

Not only do you not have to take on every single case that wanders into your practice, you really shouldn’t take on every single case that wanders into your practice! Because there is absolutely nothing gained—and actually a lot to lose—from taking on a tooth that will give you grief and lead to a mid-treatment referral anyway. 

Learning to discern which cases are a good fit for you is actually a highly valuable skill that will benefit your practice in myriad ways. By protecting your valuable chair time, you will not only bring in more revenue, but also achieve better outcomes, boost patients’ happiness, and grow your practice.

And you don’t need any fancy tech to do it either! Some people think they need a cone beam in order to do good risk assessment, but that’s just not true. Simple radiographs can go a long way when you take the time to understand what they’re telling you.

Take a tooth like the one in our Molar Endo Access Case #3, for example. If there’s no chamber to be found on the radiograph, that should be an immediate referral to the endodontist. Otherwise, you’re going to waste precious chair time and have to do a mid-treatment referral, ultimately losing you the $1000 you should have made from that 1.5 hours of work.

Good risk assessment involves more than looking at the radiographs, too. Conducting diagnostic tests (and knowing what the results mean!) and evaluating patient behavior are also key to deciding whether a case is the right fit for you. Can the patient open their mouth wide enough for you to work comfortably? Are they extremely anxious? Information like this is essential to making an informed decision.

Food for Thought

So… I want you to go from this blog post and think about two things:

1. How will you approach molar endo access differently now that you know that waiting for your handpiece to “drop” into the chamber can actually cause you to perforate and come outside the tooth?
2. What boundaries will you set regarding which types of endodontic cases you’ll take on and which types you won’t, when it comes to access? What will you do instead with that time, when you refer tricky cases out to a specialist?

Let me know your thoughts in the comments.

In addition, consider that approaching access differently isn’t just about making endo easier. Committing to doing things the right way—be it access, diagnosis, or obturation—automatically leads to a more profitable practice.

And most of all… empower yourself! You are your patients’ doctor, so they’re really looking to you for guidance with their oral health. When you feel confident in your ability to diagnose and treat their teeth, they’ll feel confident too.

Frequently Asked Questions

1. What’s wrong with “dropping” into the chamber during my molar endo access?

When your access is off, it can make finding your canals a struggle, because you lose your landmarks and could end up with mishaps like file separation during your instrumentation.

2. Are there any cases in which “dropping” into the chamber is okay?

There will be times when “dropping” into the chamber is okay—such as when a patient has a huge chamber, like in Case #1. However, it’s not a strategy you want to rely on all the time, because it can get you into trouble when the tooth is more calcified. And even when a tooth is “safe,” it’s still a good idea to consult your bitewing radiographs when deciding how to go about your molar endo access.

3. What is an alternative approach to “dropping” into the chamber?

Instead of blindly dropping into the chamber, try accessing the tooth little by little. When I run into teeth that are more calcified, I like to drill a little bit, have a peek to see where I’m at, and then poke with my Endo Explorer, continuing in this sequence until I’m safely inside the chamber.

4. What level of magnification should I use to access the tooth?

Strong magnification is the way to go—I suggest 5.0 or higher. Good visualization is the only way to be consistent and efficient in your molar endo access.

5. What should I do if I run into a tooth that’s extremely calcified?

Send that baby over to an endodontist like me! Trying to do a root canal on a tooth that’s heavily calcified will likely only lead to frustration, a mid-treatment referral, an unhappy patient, and a profit loss for your practice. Remember: There’s nothing shameful about choosing your cases strategically, and in fact doing so will actually benefit you and your practice.

6. Can I perform a good risk assessment without CBCT?

Heck yeah you can! You don’t need a cone beam to do a good risk assessment—regular ol’ radiographs will do just fine as long as you understand what you’re looking at. Don’t underestimate the value of your diagnostic tests or behavior evaluation either, as they all play a part in helping you decide which cases to take on and which to refer out.

Master Molar Endo Access With E-School

There’s no better way to perfect your molar endo access than investing in your endo training. By enrolling in E-School, my online CE course for dentists, you can gain confidence in your skills, improve your clinical outcomes, and build a more profitable practice.

– Sonia