Archives for March 2015

Doc, That Short Hurt – Part II

In Part I of this series, I wrote about why some dental injections hurt while others do not. I approached this topic knowing that there were more than five factors affecting the amount of pain felt from the “shot at the dentist.” So here we go with five more reasons:

6. Size Matters?

Dental needle photo showing needles of different sizes

Wouldn’t you be more scared of the bigger one?

Many people – both dentists and patients – incorrectly assume that the larger the needle, the more painful the dental shot is going to be. While that may seem to be true, some well designed research studies contradict this.

What is true – and this is based on years of my own observations – is that when a patient sees a large needle coming at them – they are WAY more likely to complain that it hurt.

So, the last time you received a painful shot at the dentist, did you look at the needle? If yes, the sheer size may have “psyched you” in to thinking it was going to hurt! Perhaps the time it didn’t hurt was when the dentist and/or assistant distracted you so you didn’t see the needle.

7. Good Good Good Vibrations

It is unlikely that the Beach Boys were thinking of their trips to the dentist when they composed this famous song. However, when it comes to dental injections, vibrations are good.

Many dentists, myself included, will rapidly jiggle and wiggle the area we’re about to inject. Why? According to the Gate Control Theory of Pain, the intense stimulation of the wiggling will essentially prevent the pain of the needle. Stated another way, by wiggling the area so much, that wiggling “closes the gate” that the pain signals need to travel through. See the wikipedia article if you want more info.

Dentalvibe works by creating vibrations to prevent injection pain

The DentalVibe

I can promise you that if I give you an injection without doing any wiggling, you will feel it. However, if I apply techniques from Part I of this post and wiggle a lot, you will barely feel it!

Vibrating can make such a profound impact on whether you feel pain or not that there is even a product you can buy! It is called the DentalVibe and it is basically a professional wiggler. I have not used it but have seen it demonstrated at various dental conventions.

So, if you received a dental injection that hurt, it could be in part because your dentist did not wiggle the area (please note that in some circumstances it is not possible to wiggle).

8. Speed Kills

Many patients think that the most painful part of the injection is the initial pinch as the needle penetrates. In reality, there is another part that can also hurt: the forceful pushing of the fluid (the local anesthetic) into a confined area (the cheek or gums).

photo of teaspoon and tablespoon to depict amounts of dental local anesthetic

Imagine over 1/3rd of a teaspoon injected into you over 4 seconds. Ouch! (Image courtesy wiki commons)

So, what do you think happens when you receive an entire dental shot – 1.8 cc – approx 1/3rd of a teaspoon – into your mouth in under 5 seconds? It will hurt! That entry creates tremendous pressure on the tissue at the injection site, and that leads to pain. This study confirms this fact.

One of the key elements of a pain free injection is to go slowly. I try to do it very slowly – at least 30 seconds – sometimes as long as a minute. In nearly all cases, patients say “Doc, that took a long time, but I didn’t feel a thing!”

9. Local Anesthetic Buffering

This is distantly related to Point #5 –  Choice of Local Anesthetic. But it is different enough – and its impact large enough – to warrant its own entry. And this the buffering of the local anesthetic injection. But what the heck is a buffer?

lidocaine with epinephrine has a pH below 4

This comes at a pH of less than 4.

The pH, which is a measure of the acidity of your bloodstream and tissues, is approximately 7.4. In general, the closer the local anesthetic pH is to 7.4, the less it will sting during administration. One of the most common dental anesthetic formulations in the United States – 2% lidocaine with 1:100,000 epinephrine – has a pH of 3.85! Don’t you think that will sting?

Anutra Medical buffered local anesthetic

The Anutra Local Anesthetic Buffering System I use in my office.

One way to get around this is to buffer the local anesthetic. I won’t bore you with the chemistry but ask any high schooler who took AP Chemistry and he/she can explain it in more detail. But in essence, buffering will raise the pH close to your body’s normal pH. Do you think that an injection at a pH equal to that of your body will sting? No. And many research studies support this.

So why don’t all dentists use buffered local anesthetics? Well, it is not that easy. Local anesthetics cannot be manufactured this way because they would break down with 24-48 hours. However, a new product on the market called Anutra Medical allows dentists to do just this. It has not been widely adopted yet because it is new, requires special supplies be kept in stock, and is also slightly more expensive compared to traditional injections.

Having used the product, I can say with 100% certainty that it works. Patients feel less of the shot. It’s that simple.

10. Your attitude

This is the perhaps the most important factor but also the most difficult one to describe.

If you come in feeling nervous and anxious, act somewhat hostile to the dentist and/or assistant, complain that the topical anesthetic tastes bad, don’t want to open your mouth, stare at the needle as it comes towards you, move and jerk around as the needle goes in, then the injection will hurt. I’ve had patients where I’ve employed nearly every point in this post – and it still hurt because they did not let me do my job.

If you come in nervous but allow yourself to be relaxed, keep an open mind about things, and allow us to use our techniques (super topical anesthetic, wiggling, buffering, etc.), then you will feel little to no pain on injection.

Now I realize that not all dentists are the same – and not all dentists actively seek out new products/techniques to reduce injection pain. But most do. And most will be happy to talk to you about how to reduce the pain of the injection.

Might there be a Part 3 of this series? Maybe. If you have ideas, techniques, or products, email me at and maybe I’ll come up with reasons 11 through 15!