Tags Posts tagged with "Dental Injection"

Dental Injection

Dental Anesthetic Epinephrine
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When you get a dental injection, your body wonders why on earth you’re allowing a sharp metal object to penetrate your gums!  It quickly tries to repair the damage by increasing blood flow to the area so it can carry away the anesthetic, which it views as a foreign substance. As you might have guessed, if your body’s protective response tries to get rid of all of the anesthetic, it’s not going to last very long.

Dental Anesthetic Epinephrine

This was a big problem with anesthetics back over 100 years ago.  Then, something exciting (to dentists anyway) happened!  A guy named Abel discovered adrenalin (a more common name for epinephrine) in 1897.   In 1903 Braun suggested using adrenalin as a “chemical tourniquet” to make anesthetics last for a longer period of time.

This Braun fellow recommended using epinephrine at the very small concentration of 1 part to 10,000.  That may seem weak, but we’ve found that even diluting it to 1 part to 200,000 still retains the beneficial effects of epinephrine while minimizing the side effects.

Epinephrine is what is known as a vasoconstrictor, which is just a fancy word for something that causes your blood vessels to constrict, or get smaller.

Why Dental Anesthetic Has Epinephrine

It is this vasoconstrictor effect of epinephrine that makes it so useful in dental anesthetic.  By constricting your blood vessels, it benefits you and your dentist in the following three ways.

1 – The anesthetic gets absorbed more slowly into your body because blood flow to the injection site is decreased.  Since blood levels of the local anesthetic are decreased, the risk of having an “overdose” of the dental anesthetic is minimized.

2 – Since there is less blood flow, the dental anesthetic stays put right around the nerve for a much longer time, allowing it to work for a longer period of time than it would without epinephrine.  This means that you stay comfortable throughout the entire procedure.  It also means that you might be numb for a few hours after leaving the dentist – a sometimes unwanted and embarrassing side effect!

3 – Minimizes bleeding where the anesthetic was administered.  This is great if the dentist is performing a more involved surgical procedure involving the gum tissue since it makes it much easier to see what we’re doing if there’s hardly any bleeding.

Epinephrine is the most common vasoconstrictor used in dental anesthetic in the United States.  In Europe, a vasoconstrictor called levonordefrine is commonly used.

If you prefer to not have these beneficial effects of epinephrine or if you have had heart problems, your dentist may elect to use a dental anesthetic without epinephrine. If that’s your preference and you want to seem like you know what you’re talking about, just ask your dentist for Carbocaine without epinephrine. That’s the most common brand name of dental anesthetic without any epinephrine.

If you have any questions about dental anesthetic and epinephrine, feel free to leave a comment below.  Thanks for reading!

Dental Anesthetic Makes Your Heart Beat Faster
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You may have noticed that when you get a dental injection, sometimes your heart feels like it’s going to beat right out of your chest.  You’ve probably just assumed that your heart is beating so hard because you’re nervous.

That’s partly true, but there’s another reason — the dental anesthetic actually contains something that makes your heart beat faster!

Why Your Heart Beats Faster When You Get a Dental Injection

Dental InjectionAs I mentioned above, nervousness may play a role in making your heart beat faster when you get a dental injection.  When we get nervous, our heart beats faster because our body sends out a substance called adrenaline that increases our blood pressure and causes our heart to race.

Most of the local anesthetics used in dentistry in the United States contain epinephrine (also known as adrenaline.)  Not only is your body causing your heart to speed up by releasing adrenaline, your dentist is giving you adrenaline in the local anesthetic!

Don’t worry, dentists don’t want you to have a double-dose of adrenaline to make you nervous.  Local anesthetics contain epinephrine for another reason: The epinephrine constricts your blood vessels.

With your blood vessels constricted, the local anesthetic stays near your tooth for a long time.  That way, it gives your dentist a lot of time to work on your tooth without you feeling it.  Another reason that dentists want your blood vessels constricted is so that only a small amount of local anesthetic gets absorbed into your body.

Conclusion

You may have felt your heart pounding more during some dental injections more than others.  If the dentist happens to inject the local anesthetic into a small blood vessel, it can quickly travel to your heart and cause it to beat very hard and fast.  This generally subsides after 10 seconds or so and is not dangerous to you.  Most of the time, the local anesthetic is not injected directly into a vessel and stays right near the nerve without affecting the heart.

Have you ever felt your heart race when getting a dental local anesthetic injection?  I’d love to hear your comments and questions in the comments section below.  Thanks for reading!

Update 2/25/13 – I wrote a new post about why dental anesthetic makes your heart beat faster, with more science to back it up after some comments below made me question whether or not this can really happen. You can read it here: Can Dental Anesthetic Really Make Your Heart Beat Faster?