Dental MythBuster #15: I Don’t Have to be Numb to Have an Extraction of a Tooth That’s Had a Root Canal

This is one dental myth that I personally don’t see too often. On average, I see it approximately once a month. This myth is based on this perception: because a root canal treated tooth has no nerve, if it needs to be extracted, then you don’t have to be numb (since the nerve is gone).

On the surface, this might make sense. After all, if there is no nerve, you won’t feel anything, right? Well, it turns out that is not the case. Let’s see why:

What Root Canal Treatment Does

root canal treatment x-rays

X-rays showing completed root canal treatment. Note the vertical white lines showing the canal filling material.

When a root canal is performed, the nerve tissue that lies deep inside the tooth is removed, and then that space is filled with a special filling material. The two x-rays on the left illustrate this. The top one shows the pre-operative condition of the tooth and the bottom x-ray shows the completion of the procedure with a filling material in the root canal space.

Once complete, because the nerve is now gone, the tooth will no longer be able to feel hot or cold. So if you try to swish really cold water around a tooth that’s had a root canal, you won’t feel it.

However, there are still plenty of things around the tooth that are still “alive.” The gum tissue around the tooth is alive. The ligament that holds the tooth in the socket is still alive. If you bite down hard on the tooth – you’ll feel it. All of these things…

Why You Have to be Numb for Tooth Extractions

dental elevator used for teeth extractions

Elevator used for extractions.

This may sound slightly obvious. But, to bust this myth, we need to understand why.

When a tooth is extracted, local anesthesia is given to numb the nerves associated with the tooth. What nerves would those be? They include:

  • The nerves of the tooth itself.
  • The nerves going to the ligaments holding the tooth in the socket.
  • The nerves going to the bone immediately surrounding the ligaments and tooth.
  • The nerves going to the adjacent teeth.
  • The gum tissue around the tooth.

When that tooth is extracted, great forces are exerted on not just the tooth, but the surrounding tissue. One of the instruments used is a dental elevator, which is pictured to the right. This instrument pushes the tooth out but does so by placing reciprocal forces on the structures next to the teeth.

No Local Anesthesia = Pain

alt

Even though the tip of your fingernail can’t feel much, try pulling out the nail itself!

So what would happen if an extraction was attempted on a tooth that’s had a root canal but without local anesthesia (a.k.a no “novocaine“)?

OUCH!

When the elevator is inserted (or other instrument for that matter) – the tooth itself might not “feel” anything, but the surrounding tissue will.

An analogy to how it would feel might be like having a fingernail pulled off. Sure, you can cut the tip of your fingernail and not feel anything – but try to pull it off – and you’ll be in a lot of pain!

So, if you need to have a tooth extracted, and that tooth has had a root canal – you’ll need to very numb.

 

Nail Biting: Why You Do it and How You Can Stop

I am pleased to have Tsgoyna Tanzman contribute this unique and informative article. Please keep in mind that the information posted represents her opinions – and does not mean I endorse or validate her techniques. While I can personally validate the majority of her information on nail biting, I cannot attest to the efficacy of NLP.

Why do People Bite Their Nails?

Simple. The same reason people do anything.

To gain pleasure and/or avoid pain. No matter what we do in life, it nearly always boils down to this simplistic behavior. Whether you’re going after a goal such as getting a dream job or finding your soul mate, we believe the pursuit and attainment of that end goal will make us feel good (pleasure) and help us avoid pain (homelessness and loneliness).

Why do YOU Bite Your Nails?

At some point in your early life there was most likely a condition, perhaps a parent or other significant role model, who bit his or her nails and your duckling brain imprinted it as a means of connection and identification. You felt good. You belonged. Then the next layer of feel good happened when you associated the behavior with more pleasure. In other words, the behavior became a self-soothing event. It rewarded you. You felt calmer.

photo of fingernail worn down from nail biting

The evidence! The wear pattern on this fingernail is consistent with chronic nail biting.

Unbeknownst to you, you activated your parasympathetic nervous system, triggering a cascade of hormones that calmed you down and gave you pleasure. Your brain subconsciously made a connection, conditioning you to connect the two events. Since the brain likes efficiency, it got to work and laid down a neural highway. If I do this (bite my nails) then I get this (pleasure and I avoid pain).

Dental Complications from Nail Biting

Nail biting is complicated because it is both pleasure and pain tied up in a one-two punch. It has the immediate short-term effect of soothing, but it is coupled with some pretty nasty long-term side effects.   Here’s the ugly truth:

  1. Despite the fact that enamel is the strongest substance in your body, your teeth are not meant to be chew nails. Excessive and continual pressure from nail biting can cause your enamel to wear down, chip, fracture and/or misalign your teeth, as well as potentially contribute to temporomandibular joint pain. (TMJ). In fact, the Academy of General Dentistry estimates nail biting can result in up to $4000 more in dental bills. So much for the pleasure principle.
  2. Beneath our nails are some of the most gnarly bacteria, viruses, and fungi. In fact, there are as many as 150 different bacteria that can live under our nails including salmonella and E.coli.
  3. As a nail biter you’re a transporter of bacteria and those bacteria can lead to infections that may lead to gingivitis.
  4. Broken and/or jagged nails can tear or cut the gums. The Mayo Clinic warns that viral infections like herpes and the HPV virus can be transmitted from open cuts to the gums.
Nail biting photo showing characteristic groove with front teeth.

Photo showing a pronounced groove on her two lower front teeth from chronic nail biting. She is in her mid 20s. If this continues, what will her teeth look like in her 40s? Photo Dr. Nicholas Calcaterra.

Despite all of this, people will continue. The logical part of your brain tells you to stop biting your nails. If you’re like most nail biters you’ve already tried “everything.” You’ve tried the bitter nail polish and while it initially worked you strangely overrode the aversion, sufficient to keep biting. You’ve tried rubber bands, Band-Aids, gloves, chewing gum, and exhaustive willpower. You can never punish your way into changing a behavior and expect it to last. These “outer game” strategies are like trying to stop a train going 100 mph.

So How Do You Stop Nail Biting?

Before it begins and from the inside out.

If that just caused you to chomp down, on your very last nail, hold on. One of the first questions I ask my nail biting clients is, “How do you know it’s time to bite.” Most often they immediately answer, “I don’t, it’s unconscious.“

As a Master Practitioner of Neurolinguistic Programming, I know that all behavior is encoded in our brains in patterns we repeat efficiently. Bringing that pattern of behavior to a conscious level right down to the nanosecond, just before the fingers are in the mouth, is the most important first step to effectively altering the pattern. The truth is you’re an expert at biting your nails and everyone has a unique repeatable sequence of events. It may begin with a visual or tactile inspection. Your right thumb is the lead inspector, rubbing each finger to find roughness. Or perhaps you rub your fingers against some fabric. Or you visually inspect for evidence of a hangnail. When we are able to identify a pattern and then consciously decide on a desired different behavior we want, it sets the foundation for making this neurological shift.

How Does Neurolinguistic Programming Help?

Besides being a mouthful of syllables, it’s a method of influencing brain behavior (“neuro”) through the use of language (“linguistic”) and other types of communication to enable a person to “recode” the way the brain responds to stimuli (“programming”) and manifest new and better behaviors. This field of science/psychology came on the scene in the 1970’s and if it were renamed today, it might be called Upgrade Your Operating System.  Why NLP works quickly and effectively is because it scrambles the pattern of behavior, much like scratching a record, rendering it unable to play the same way.  It fixes the bugs and re-patterns the brain to new more desirable behaviors. Using our basic modalities Visual, Auditory, Kinesthetic (feeling), Olfactory (smell) and Gustatory (taste) we are able to modify and shift old behaviors.

If you truly want to stop biting your nails, you have to work from the inside out. Align your subconscious and conscious minds. Re-pattern the behavior and re-condition your associations.

What’s the upside? Healthy aligned teeth, beautiful nails, restored confidence and overall improved health, and you might just save thousands of dollars.

Webmaster’s Note: I hope you enjoyed this article from Tsgoyna Tanzman. If you would like to learn more about this unique approach, visit her website at howtostopbitingnails.com. She offers a complementary “Let’s Get Growing” consultation.

Don’t Shock Me Bro!

As a dentist in private practice, I administer local anesthesia routinely. Or, in layman’s terms, I give numbing shots daily. That’s just two ways of saying the same thing!

Dental local anesthesia infiltration photo where no electric shock will occur

This type of injection is highly unlikely to give you an electric shock sensation

Occasionally, when I am doing certain injections (and note that there are different types of injections that dentists administer – more on that later), the patient will experience an electric shock sensation originating from the injection area. This ends up being quite a shock to the patient (pun intended) with me then subsequently spending significant time explaining why/what happened.

In addition to seeing this happen periodically in my own office, I get tons of comments and inquires on this blog about “the electric shock they got” from the dentist’s needle. Since nearly all of my articles are either about my own experiences – or from inquires I get on this blog – I decided it was time to do a post on this phenomenon.

Infiltrations versus Nerve Blocks

To understand why the electric shock occurs, a little background information is needed.

Femoral nerve block with an ultrasound

A nerve block guided by ultrasound being done by an Anesthesiologist.

In medicine – and I do consider dentistry to fall under the medical umbrella – there are various techniques for numbing a particular anatomical region. An infiltration is when local anesthetic is deposited directly adjacent to the site to be worked upon. In these cases, the local anesthetic works by affecting tiny, microscopic nerve endings that almost resemble a spider web.

In contrast, with a nerve block, the local anesthetic is deposited adjacent to a large branch of a nerve. This ends up numbing everything that the nerve supplies downstream from the area the anesthetic was administered.

To use an analogy: picture a tree. An infiltration is where anesthetic is placed next to a single leaf. A nerve block is when the anesthetic is placed next to a large branch close to where it is coming off the trunk.

Shock and Awe

When it does occur, the electric shock phenomenon is nearly always associated with a nerve block (as opposed to an infiltration). Why does this occur?

The shock sensation is believed to occur when the needle makes contact with part of the nerve trunk (sources: here, here, and here). The needle basically enters the tissue, touches the actual nerve, and the trauma from that immediate contact provokes a signal that your nervous system perceives and interprets as an electric shock feeling.

photo of needle and skull bone where you give a dental nerve block

In a mandibular nerve block, the needle is aimed right where a large nerve trunk (the inferior alveolar nerve) is about to enter the lower jaw (the mandible)

Some key facts:

  • The incidence of this occurring is between 1.3% to 8% of the time for mandibular nerve blocks (the large difference is based on different sample sizes).
  • Studies have shown that an electric shock sensation does not place the patient in a higher risk category for permanent nerve injury.
  • The most commonly involved nerve is the lingual nerve (which will give rise to a shock sensation in the tongue on the affected side.

As you can see, since the origin of the electric shock is contact with a nerve trunk, it is nearly impossible for this to occur with an infiltration.

What to Do if You Feel the Electric Shock?

With dentists administering millions of injections per year, this occurs on a regular basis throughout the world. Keep in mind:

bullseye showing that electric shock is due to hitting the nerve

An electric shock means your dentist hit a bullseye.

  1. Although the feeling was unpleasant and unexpected, the research clearly shows that this does not place you at a higher risk for permanent nerve issues (see bullet point #2 above).
  2. In many times, you get numb extremely quickly.
  3. This happens to all dentists periodically and this phenomenon alone does not mean your dentist is unqualified or negligent.

Since this occurs when the needle makes contact with the nerve trunk, it means your dentist was dead on with his/her aim. So, if you like, you can congratulate him/her on hitting a bulls-eye! Or, just understand that the human anatomy is unpredictable, and sometimes things like this happen.

Note: the sources used for this post are listed above and are also based on my own experiences. Note that I cannot answer emails to me asking for dental advice. The title for this post is based on the “Don’t Tase me Bro” incident and I have no relationship with Mr. Meyer. This post should not be construed as me providing commentary on that incident.

Dental Local Anesthesia and Ehlers Danlos Syndrome

Ehlers Danlos Syndrome is a group of similar inherited disorders that adversely affect the connective tissue. Patients with this disease experience problems in the skin, joints, blood vessels, and other areas. In addition, some disorders within the syndrome also make the individual resistant to local anesthesia.

Unfortunately very few dentists are aware of this phenomenon. And in addition, there are patients out there with undiagnosed Ehlers Danlos, as well as patients with EDS who are not aware of the issues with local anesthesia. What happens? The patient ends up having a very unpleasant time at the dentist with both the dentist and patient trying to figure out what is going on!

About Ehlers Danlos Syndrome

Ehlers Danlos and dental local anestheticIt is not the point of this blog post to talk about the Syndrome in great detail. There are plenty of other sites out there that accomplish this. However, to understand how this affects dentistry and the dreaded “novocaine shot,” you need to know a bit about the disease.

Ehlers Danlos affects connective tissue. Connective tissue is basically the “glue” that holds other tissue and organs together. Specifially, there are defects with the production of collagen, which is the major protein in connective tissue. While there are six major types of EDS, they are all generally characterized by hypermobile joints (joints that can move way beyond what would be considered normal), joint pain, fragile and easily bruised skin, and other findings.

Not all of the genes responsible for Ehlers Danlos are known and there is active research into all parts of this syndrome.

Why Does Local Anesthesia Not Always Work?

First, it needs to be mentioned that not all of the six types of EDS make the patient resistant to dental local anesthetic. Based on research (here and here), it appears that Type III – Hypermobility is the one in which this phenomenon is seen.

dental injections don't always work in Ehlers Danlos

For those with some types of Ehlers Danlos, you will need MANY injections of very specific anesthetics for effective local anesthesia.

Unfortunately, the mechanism behind why the local anesthesia is less effective is not well understood. The current theory focuses on the “looseness” of the connective tissue. Since the connective tissue is defective, it is very easy for the local anesthetic to quickly move away from the site that is being anesthetized. Stated another way, the connective tissue barriers that hold the local anesthesia in place for the duration of the dental procedure are weak and easily broken.

The end result is that the patient is not sufficiently numb for the dental procedure, leading to pain. Patients get confused, discouraged, angry, and ultimately avoid the dentist, which then makes things even worse down the road.

What Should Dental Patients Do?

Ehler Danlos hypermobility which can affect dental local anesthesia

If you can do this with your thumb, you may have Ehlers Danlos.

As a dentist who treats patients in private practice, I am disappointed that this issue is not well known in the dental community. Ask most dentists and unfortunately, most will not be aware of this. In fact, in what is considered the bible of dental local anesthesia (A Handbook of Local Anesthesia by Stanley Malamed), there is no mention of phenomenon (I searched the 6th edition).

Here are some tips:

  1. Find a dentist who has experience with Ehlers Danlos. There is nothing wrong with calling an office and asking if the dentist is familiar with EDS and this local anesthetic phenomenon.
  2. Identify yourself early on as having Ehlers Danlos to the hygienist and dentist.
  3. Find an opportunity to meet with the dentist in advance of any procedure requiring local anesthetic to review the plan (remember that the office may have to order a special type of local anesthetic).
  4. Consider taking a medication beforehand to relax you.
  5. Be ready for a longer than normal appointment.
  6. At the completion of the appointment, especially if it was successful, ask the dentist for detailed records on the local anesthesia (what local anesthetic, how much administered, where administered, etc.)

In some cases, nitrous oxide and/or IV sedation may be necessary to complement the local anesthesia.

My own experience treating patients with Ehlers Danlos has shown that most of the time, we can achieve local anesthesia. I attribute my success to knowing the pharmacology of local anesthetics as well as other injection techniques. To use a pun based on EDS, with a little “flexibility” in selecting local anesthetics and injection sites, we can nearly always succeed!