Dental MythBuster #16 – You Shouldn’t Have an Infected Tooth Pulled

Tooth with an abscess infection needing treatment

This infection needs treatment ASAP.

This myth is quite pervasive on the internet, but I’ve rarely seen it in private practice. The typical scenario is as follows:

A patient, most often in intense pain and with significant swelling, goes to a dentist. The dentist diagnoses the patient as having an infection. He/she then extracts the tooth and often prescribes antibiotics. 1 to 2 days later, the patient is still having some pain and swelling, and then reaches the conclusion that the tooth should not have been pulled. Ultimately, the infection/swelling resolve.

There are many variations to this dental myth, but the net result is the assumption by the patient that the tooth should not have been extracted because it was infected.

What Causes Dental and Oral Infections

There are many different types of dental infections. Some originate in the tooth itself. Others originate in the tissues directly surrounding a tooth. Still others occur on surfaces within the mouth such as the tongue, cheeks, and floor of the mouth. But the vast majority develop first within a tooth and then spread to the surrounding gums and bone.

decayed and extracted tooth photo that caused an infection

This decayed tooth first developed an infection inside but then it spread to the surrounding areas. Immediate extraction was the only way to deal with this infection.

The above tooth shows a large cavity underneath a crown. The cavity is the source of the infection and is filled with bacteria. Stated another way, the infection first developed within the tooth. With time, it spread to the surrounding gums and bone, resulting in pain and swelling. Immediate extraction was the only option.

Why Infected Teeth Need Immediate Treatment in Nearly all Cases

We’ll take this quote from an Oral Surgery textbook:

“The primary principle of management of teeth infections is to perform surgical drainage and to remove the cause of the infection” (From Contemporary Oral and Maxillofacial Surgery by James Hupp, DMD, MD)

Or, to quote another unnamed surgeon:

“Never let the sun set on pus”

So, what do all these quotes mean? It basically means that surgical intervention is required for tooth infections.

“Surgical intervention” can range from extracting the tooth to draining the pus to other techniques.

Cases When a Tooth Should Not be Extracted

Keep in mind that each and every tooth infection is unique and needs to be evaluated on its own. Factors that a dentist or oral surgeon will consider include the location of the infection, size, consistency (is it a hard swelling or softer), patient’s age, patient’s medications, patient’s medical conditions(s), presence of systemic symptoms (fever, malaise, blood analysis), tooth or teeth involved, previous antibiotic use, and many other factors.

There are some clinicians who believe that immediate extraction should not be done in cases of a very unique type of dental infection called pericoronitis. They recommend surgical drainage instead.

pericoronitis of a lower wisdom tooth showing the infection

Pericoronitis of a lower third molar. Note the redness and swelling of the gum tissue overlying the tooth. Some clinicians believe that immediate extraction should not be done.

But there are other clinicians and textbooks which recommend immediate extraction in cases of pericoronitis.

Dental Myth Busted

As stated earlier, every tooth infection is different and the recommended treatment is based on the unique qualities of that infection. As we learned earlier, in cases of acute infection, surgical intervention is required. And in nearly all cases, getting the tooth pulled is appropriate. So it is a myth to say “you shouldn’t have an infected tooth pulled.”

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.

 

Dental MythBuster #14: A Swollen Lip After a Dental Visit Means You’re Allergic to Novocaine

This is one dental myth that every dentist has to deal with at some point. And that is the myth that if a child’s lip swells up after a dental visit where local anesthetic was used, it always means the child must be allergic to something the dentist injected.

And to make matters worse, this myth is then often propagated by the child’s pediatrician.

What would you think if you saw this the day after your 8 year old got a filling on his lower right molar:

swollen lip from biting while numb after filliing

Lower right lip swollen after a filling was done on the lower right.

That looks pretty nasty right? Something clearly happened here. In my own experience, and in talking to other dentists, parents generally do one of four things upon seeing this:

  1. Parent immediately heads to the closest ER or emergency walk-in clinic.
  2. Parent immediately calls the pediatrician for an emergency appointment and is seen that day.
  3. Parent gets on Google, becomes almost immediately convinced of an incredibly dire situation, and then does either #1 or #2.
  4. Parent calls the dentist office.

Wouldn’t it make sense to call the dentist office? After all, it was the dentist who did the procedure, wouldn’t he/she know what is going on?

But unfortunately, options 1, 2, and 3 are often pursued. And in many of those cases, an incorrect diagnosis is frequently made, which leads to unnecessary finger pointing, as well as wasted time, confusion, and missed school for the child.

So, what does it mean when the lip swells up after a dental appointment when local anesthetic was used?

Swollen Lip = Lip Biting While Numb (99.99% of the time)

Here are two cases I’ve seen in my office:

swollen lip after dental work means lip biting

Swollen lips after dental work. Both patients admitted that they inadvertently bit and/or played with their lips while numb.

The above photos look unpleasant, right? In both cases, lower teeth were given local anesthesia, and that numbness extended to the lip. And in both examples, the patients admitted to repeatedly biting their lip.

The repeated biting led to swelling, bleeding, and bruising. Many times, the child has no recollection of doing it, because the child was numb and felt no pain. But the next day – whoa!

It is quite easy to see how this can come from biting. Go ahead and try to bit your lower right lip with your upper front teeth. Easy, right? Do this a couple of times very hard while you’re numb and you’ll end up looking like the one of the photos.

Why This is not an Allergy

Despite seeing this on a regular basis, many dentists (myself included) still have to deal with accusations and/or false diagnoses of allergies from the injection. Here are some key points:

  • Location. The injection site is nearly always located far away from the traumatized area – in some cases nearly two inches. If it were an allergy, why then is the injection site totally normal? See the photo below.
  • Appearance. In general, allergic reactions do not produce a localized ulcerated area away from the injection of the alleged allergen. The appearance of this is simply not consistent with an allergic reaction.
  • Lack of Systemic Symptoms. Even less severe allergic reactions will produce other symptoms such as dry mouth, hives, and other findings. None of these are typically present in lip biting.
dental injection photo next to tooth

Dental injection adjacent to a 12 year molar. How could this produce an “allergic” reaction on the lip only when the injection site is so far away?

Of course, allergic reactions can occur from the injection. However, they are exceedingly rare, and don’t present like this. For more information, see this three part series.

What Should You Do?

So, if you or your child’s lip is swollen after receiving local anesthetic, what should you do? Call your dentist. Generally speaking, pediatricians, PAs, and NPs do not have experience seeing these types of things, and then come up with what we call “creative diagnoses” which are usually incorrect. General dentists and pediatric dentists see lip biting all the time and can guide you on how to handle it.

But to stress this point, it is a myth that a swollen lip (in the absence of other findings) after a dental visit means you are allergic to lidocaine (mistakenly called novocaine).

Until the next dental myth is busted…

Dental MythBuster #13: A Dental Filling Will Last Forever

Fortunately, this dental myth does not come up very often. When it does, the myth usually comes up when I have to deliver news along the lines of “I have a concern about one of your fillings.”

Most patients understand that dental fillings are usually not lifelong permanent solutions. But some patients don’t. Like many other medical devices and appliances, fillings don’t last forever.

Problems with Dental Fillings

There are all types of problems that can occur with dental filings. Below are some examples:

broken mercury amalgam filling in a tooth

A broken silver amalgam filling. This will need to be replaced.

The tooth above shows two premolar teeth, both with amalgam fillings. One of the fillings has cracked. There are many reasons why it cracked – but they go beyond the scope of this post. However, to summarize, after being chewed upon several hundred thousand times, it has finally failed.

high quality photo of broken lower molar tooth with a filling

Here, both filling and tooth broke!

In this photo, a large portion of both tooth and filling broke. In this particular case, the filling had been there for over 20 years, but the remaining tooth structure was so weak it finally gave out. In this case, this patient needed a crown.

In addition to the above two examples, dental fillings can fail for many other reasons. And many will fail due to a combination of multiple factors.

What other medical appliances last a lifetime?

On occasion, I will come across a patient who is particularly disturbed that one of their fillings done during the Clinton presidency needs to be replaced. I will often politely respond by referencing other medical appliances:

cardiac pacemaker is like a filling and can last seven years

On average a pacemaker lasts seven years.

What do the above 3 devices all have in common? These are all manmade devices designed to replace or repair damaged or missing human tissue. And that is exactly what a filling is.

When I mention these examples, most patients begin to understand fillings typically have a finite lifespan. And then the myth is busted…

How Long Should a Filling Last?

This is difficult to answer since there are so many factors at play. I’ve seen fillings last over 40 years while others fail within 1 to 2 years. The factors can include:

  • Type of material (silver amalgam vs. resin composite).
  • Location in the mouth.
  • Oral hygiene.
  • Sugar intake.
  • Occlusion (how the teeth come together).
  • Skill level and attention to detail of the dentist who placed it.

So, while occasionally a filling can last a lifetime, that is not the norm. Just like nearly all other medical appliances and devices, they can and do wear out. It is a myth that all fillings will last forever.