Dental Anesthesia

 

First of all, if you hate dental shots, it's because you need to work with a dentist who has some more modern techniques for getting patients numb. Dental shots need not be painful. We work with VERY high fear patients all the time who get over their fears within a couple visits.

Dr. Chuck and I have put a great deal of time into improving this difficult part of dental visits. We use some very unique techniques (some we invented ourselves!) and new materials, that get raves from patients who used to just dread getting dental anesthesia. At least once a day, AFTER we have given an injection, a patient will ask "Did you already give me the shot!?" The children in our practice never know they are getting injections until they are in their mid-teens.

I know you are thinking "Blah, Blah, Blah".... 

But I get it!... I used to HATE shots myself (because my dad was a physician who gave us terrible shots! ha) But,.. Dr. Chuck has done all my dental work for 20 years and I never even feel his shots at all. He has just the right touch, even with those huge hands. I'd like to think I have as nice a touch as he has.  

So,... that said,... if it's the shot that bothers you, we can help. 

We have some techniques for getting you numb that are so kind that we can use them on ourselves! Here is a photo of Dr. Lynda numbing up her own tooth with a very cool instument that makes this part of the process a breeze....

   

If you think you are allergic, that's another story.....

For patients who think they are allergic to local anesthetic

If you've had a bad reaction after getting a dental injection it is very unlikely that you were allergic to the anesthetic itself. It was probably a reaction to the epinephrine in the anesthetic or a preservative used in some kinds of anesthetics. Read on and you will completely understand the issues.

Most likely, a strange reaction to dental anesthesia is due to the epinephrine - a chemical that makes the numbness last longer.

First, there are two basic types of dental anesthetics:

1. Esters

Esters were the first class of local anesthetic to be discovered (cocaine) and later to be synthesized (Novocaine).  They contain such drugs as Cocaine, Procaine, Tetracaine, Chloroprocaine and Benzocaine. 

"Novocain" was the brand name for the very first chemically synthesized, non addictive, injectable local anesthetic ever produced.  It was invented at the end of the 19th century.  It is no longer used in dentistry partly because it has a short duration, and partly because it is highly allergenic.  High allergenicity is a trait common to all the ester based anesthetics.  In general, a patient known to be allergic to one ester anesthetic is likely to be allergic to all ester anesthetics.

Today, only benzocaine is routinely used in dentistry as a topical application (applied with a cotton swab prior to injections).   

WE DO NOT USE BENZOCAINE IN ANY FORM AT FIDDLEHEAD DENTAL. We use 5% lidocaine gel (lidocaine is not an ester)  and it works quite well as a topical anesthetic to numb the gums before the shot is given.

2. Amines

Amines were invented later.  They include Lidocaine, mepivicaine, bupivicaine, articaine, prilocaine and bupivicaine.  They all have the advantage of being  non- allergenic.  To our knowledge, there has never been a true, documented allergic reaction to an amine anesthetic that contained no preservatives.  WE USE LIDOCAINE  or SEPTOCAINE WITH OR WITHOUT EPINEPHRINE.

Since dentists now use amine based anesthetics, we see almost no allergic reactions to the injectable local anesthetics.   If you have suffered allergic reactions at the dentist's office, it is most likely that the reaction was to the  benzocaine topical anesthetic applied with a swab before the shot, or to the preservative used in anesthetics containing epinephrine. 

Preservatives

Once in a while, a patient may have a legitimate allergic reaction to a dental anesthetic.  It is likely that he or she may in fact be allergic only to the bisulfite preservative.  If the allergic reaction was not too serious, it may be worth trying again with either mepivicaine or prilocaine (two other kinds of anesthesia) without epinephrin.  

Anesthetic manufactures do not use preservatives in carpules that do not also contain Epinephrin. 

Why are preservatives added? All standard local anaesthetics contain the preservative sodium bisulfite or metabisulfite. The preservative is necessary to keep the epinephrine fresh (epi quickly deteriorates and becomes useless otherwise). Most standard local anesthetic cartridges (called lidocaine in the U.S. and lignocaine in the U.K.) have epi added.

If you think you might have an allergy to Sodium Metabisulphate it's important to learn more. This chemical is in foods, cosmetics, and all sorts of things you might come in contact with. Here's a great link to learn more: Sodium Metabisulphate Allergies

 

What if you have had an allergic reaction to amine local anesthetics?

If you think you are allergic to dental anesthetics, the first thing you should do is to visit an allergist to see if you really are allergic to the amide based anesthetics.  You could be saving yourself a LOT of difficulties in the dental office!  

Probably, you are only allergic to the preservative used to stabilize the vasoconstrictor, or the topical that the dentist used to swab the area to be injected.  The chances are that the use of mepivicaine or prilocaine without vasoconstrictor   (epinephrine) will NOT cause an allergic reaction provided that no ester based topical is used beforehand!   

Testing for anesthetic allergy using skin tests

One of the most commonly used skin tests used by physicians to test for general allergy is called the T.R.U.E. Test®.  This is a patch test that applies 23 allergens to the skin contained in 12 polyester patches.  One of the patches contains a mixture of several anesthetics and is used to test for allergy to local anesthetics in general.  The mixture used includes two ester based anesthetics and one amine based anesthetic.  This mixture of anesthetics is called the "Caine Mix", and most people are not aware that a positive T.R.U.E. patch test does notnecessarily indicate that the patient is allergic to injectable dental anesthesia.  The patient may instead be allergic to only the ester based anesthetics (generally used only as topicals in dentistry), but not to the amines which are injected after the topical and produce the profound anesthesia necessary for dental surgeries.  

If you should decide to try dental treatment with local anesthetic, take these precautions:

• The dentist should always use mepivicaine or prilocaine without epinephrine, because If you have suffered allergic reactions to dental anesthesia in the past, there is a good chance that your allergic reactions were caused by the preservatives.
• Ask the dentist if the topical anesthetic is 5% lidocaine gel.
• Take 50 mg of Benedryl, or a similar antihistamine an hour before the dental appointment. Benedryl (diphenhydramine) is available at pharmacies without a prescription.

How TRUE allergies work? 

The signs and symptoms of allergic reaction include:

• generalized body rash or skin redness
• itching, (hives)
• difficulty breathing
• swelling of the throat
• asthma
• abdominal cramping
• irregular heartbeat
• hypotension (low blood pressure)
• swelling of the face and lips (angioneurotic edema)

Reactions to epinephrine  are:

• quick onset of a racing heart beat that quickly subsides after 5-10 minutes
• light-headedness
• perspiration
• Much like you feel just seconds after you narrowly avoid a serious accident. (This is the body's natural mechanism that floods your body with the chemistry some call "fight or flight".)

Bottom-line: There are ways that we can help you determine if you really do have a true allergy, .. however, it is very, very unlikely. In our practice, for patients who think they have an allergy to dental anesthetics, we use the Lidocaine with no epinephrine and have never had anything but good outcomes.