You learned all about the different anesthetic formulations and types when you were in school. It doesn’t matter if it was 3 months ago or 30 years, it is amazing how quickly that information can become lost in our memory banks. On top of that, your office may not use all the varieties on a regular basis, making it even harder to recall the solution types and their best uses.
The thing is you never know when something will come up and you need to use a different type of anesthetic solution. Perhaps the formulation your offices uses is on back order, or you are working in a new office. Maybe your volunteering your time, and what is available isn’t something you are used to. This review is aimed to increase your confidence regarding your knowledge of the different formulations and what they are used for.
So, let’s dust off the memory vault and review...
Oh yes, the dental go-to gold standard of anesthetic. This anesthetic became the best universal option when we stopped using “Novocain”. Lidocaine is the generic name and the most widely used. Some of the brand names include Xylocaine, Alphacaine and Octocaine.
Lidocaine is used for both injectable and topical applications. The most common injectable solutions are 2% lidocaine with 1:100,000 epinephrine and 2% lidocaine with 1:50,000 epinephrine.
For the most part, both offer the same qualities of profound anesthesia. However, the concentration with 1:100,000 epi is generally used more frequently. The 1:50,000 epi is more likely used in surgical cases when hemostasis is an issue. Another option, is if you are completing non-surgical therapy. Administering this concentration into the dental papilla will aid in hemostasis as well.
As a reminder the concentration of the vasoconstrictor must be considered especially for our cardiac compromised patients. The higher the dilution of vasoconstrictor, the better for these patients. As the amount of epinephrine increases the more vasoconstriction happens. Allowing for reduced blood flow in the area (providing hemostasis), but also increasing cardiac output.
Some things to consider, lidocaine is it is metabolized in the liver, so be cautious for patients with a compromised system. Also, it is one of the anesthetics which can be used during pregnancy (2nd trimester is ideal).
I love this anesthetic. Probably because it was formulated for dentistry in mind. It is quickly gaining popularity in the U.S. and is widely used in Canada and European nations. You may also know it is Septocaine, Zorcaine or Orabloc.
One reason I like this anesthetic is because it’s mainly metabolized via the blood stream by cholinesterase. Making it ideal for liver and kidney compromised patients. The half-life of the solution (on average) is 45 minutes. Which means nursing moms can clear it from their system so much quicker. While there is not strong evidence that the anesthetic is found in breast milk, this could help alleviate concerns regarding breast feeding after anesthetic delivery. I have even heard some new information about its potential use with pregnant patients as well. All due to its quick half-life and process of metabolism. Currently the FDA does have it as a category C drug. I don’t foresee this category changing since it’s so hard to test drugs on pregnant humans.
Another bonus of articaine is its ability to diffuse through bone better than most anesthetic solutions. Using it for palatal injections and mandibular infiltration works well. Especially if you are working with children. Instead of giving an inferior alveolar (IA) injection you could infiltrate around the molars and achieve profound anesthesia.
It does have a bad reputation for causing paresthesia with mandibular nerve blocks. However, the research I have come across indicates it is not statistically more significant than other anesthetic formulations. Even Stanley Malamed, who I consider the Guru of oral anesthesia, has worked to debunk this concern.
The common formulation is 4% articaine with 1:100,000 epi and 4% articaine with 1:200,000 epi. Often the solution with the 1:200,000 epi is selected for cardiac compromised patients.
Mepivacaine has many other names such as Carbocaine, Polocaine, Scandonest, Isocaine and Arestocaine.
This anesthetic has two main formulations. 3% mepivacaine plain and 2% mepivacaine with 1:20,000 levonordefrin. Making it the only anesthetic commonly used with an alternative to epinephrine for vasoconstriction. The beauty of levonordefrin is it is one-sixth as potent as epinephrine, which is a bonus for our cardiac impaired patients.
You may remember that anesthetics are excellent vasodilators, which is counter intuitive to what we want them to do. Mepivacaine is the least effective vasodilator of the main five we use. This means the plain anesthetic formulation works well for short duration dental appointments and can provide soft tissue anesthesia for an hour or so.
Please be aware that it does metabolize in the liver, even more so than lidocaine so take caution for liver compromised patients.
Prilocaine also has two formulations. One as a 4% plain solution and the other as 4% with 1:200,000 epinephrine. It is also referred to as Citanest (for the plain) or Citanest Forte (with epi).
Again, due to the low concentration of epinephrine, this anesthetic formulation is a perfect selection for cardiac impaired patients. It is also the other anesthetic that is an FDA category B anesthetic which moves it up the list for anesthetic selection for pregnant patients. It is metabolized in the liver however, most of it is cleared out of the system before entering.
A point to remember is prilocaine plain has different durations of anesthesia depending on where it is injected. If you give a block injection (like an IA) the patient could be numb up to an hour. However, with infiltration it only lasts about fifteen minutes. (These time frames are for pulpal anesthesia, soft tissue anesthesia will last much longer.)
I call this one the “Big Pappy” of anesthetics. Bupivacaine also known as Marcaine is the go-to anesthetic for our patients who need deep and prolonged anesthesia. It will often be used for patients who have a challenging time getting and staying numb.
Due to its high potency it only comes in one formulation, 0.5% bupivacaine with 1:200,000 epinephrine. This anesthetic can provide hours of pain relief. Which makes it a great choice for patients who may suffer from post-operative pain or for those who may not be able to have their urgent dental issue addressed for an extended period.
Because it is so potent, this anesthetic should be used with caution with all patients regardless of health status. Especially if it is used in combination with other anesthetics.
There is so much more we could discuss about all of these anesthetics such as proper dosage and a deeper look into drug interactions. Perhaps that will be for a different day.
Now that you have your memory bank dusted off, you will have the confidence to select the best anesthetic solution to give your best shot.
Handbook of Local Anesthesia 6th ed. S. Malamed
Local Anesthesia for Dental Professionals 2nd ed. K. Bassett, A. DiMarco, D. Naughton