The anesthetic shortage we all experienced recently put us in a new situation: having to work with local anesthetic types we weren’t accustomed to. Many of us were used to the “Spanish” anesthetic—typically Articaine 4% with 1:100,000 Epinephrine. Suddenly, we found ourselves working with “Colombian” anesthetic, which is generally Lidocaine 2% with 1:80,000 Epinephrine.
While both ultimately achieve the same goal, there are fundamental differences you absolutely must keep in mind while working. Knowing these distinctions will help you avoid unexpected issues and enable you to get the best out of each type.
In this article, we’re going to summarize the top 7 practical and scientific differences between “Colombian” and “Spanish” local anesthetics.
1. The Syringe Itself… A Different Feel in Your Hand
The very first thing you’ll likely notice, even as you’re just loading the cartridge, is that its tactile feel is distinct.
What’s the Deal? The Plunger of the “Colombian” anesthetic cartridge tends to have a “stiffer” or “harder” movement when you inject, especially when compared to the “Spanish” anesthetic, which typically offers a much smoother, easier glide.
Why Does It Feel Different? This is most likely due to variations in the materials used to manufacture the cartridge itself, or perhaps the specific type of rubber used in the plunger. This isn’t a flaw in the anesthetic solution; it’s simply a difference in sensation. It will require a slightly firmer hand pressure from you to ensure you inject at the same slow pace you’re used to.
2. The Needle Stick… Might Sting a Little More
Some clinicians and patients have observed that injections with “Colombian” anesthetic can be a bit more painful than with its “Spanish” counterpart.
What’s Happening Here? “Colombian” anesthetic (Lidocaine) has a slightly higher acidity (lower pKa) compared to “Spanish” anesthetic (Articaine). Our tissues prefer a more neutral environment, so injecting any acidic solution into them can cause a sensation of burning or discomfort.
The Key Takeaway: To significantly minimize this sensation, inject extremely slowly. The slower you go, the more opportunity the tissues have to buffer the solution’s acidity, which, in turn, reduces the pain felt by the patient.
3. Onset Speed… A Tug-of-War Between Theory and Reality
Now, here’s an interesting scientific point to consider.
Theoretically: “Colombian” anesthetic (Lidocaine) should, in principle, start working faster than “Spanish” anesthetic (Articaine). Why? Because its pKa is lower. And the lower the pKa, the quicker the anesthetic molecules can penetrate the nerve membrane, leading to a faster onset of action.
But in Practice: Many of us actually feel that “Spanish” anesthetic (Articaine) works faster! What’s the mystery?
The secret lies in two distinct advantages Articaine possesses:
-
Higher Lipid Solubility: This property allows it to “dive” deeper into tissues and diffuse more easily throughout them.
-
Thiophene Ring: This is a unique chemical structure in Articaine that grants it exceptional diffusion capabilities.
The Bottom Line: If you inject “Colombian” anesthetic precisely at the target nerve, it will work quickly. However, “Spanish” anesthetic is much more “forgiving” if your injection isn’t perfectly on target, simply because it can diffuse and reach the desired area with greater ease.
4. Potency… Spanish Takes the Lead
Have you ever felt the need for a larger volume of “Colombian” anesthetic to achieve the same depth of anesthesia? Your intuition is correct.
What’s the Reason? Anesthetic potency is directly linked to its lipid solubility, which we just discussed. Since “Spanish” anesthetic (Articaine) boasts higher lipid solubility, its overall potency as an anesthetic is slightly greater. This implies that you might need a slightly larger quantity of “Colombian” anesthetic to reach the same profound level of anesthesia you’re accustomed to with “Spanish” Articaine.
5. Duration of Action… Not a Significant Difference
What’s the Story Here? The duration of action for an anesthetic largely depends on its ability to bind with body proteins (Protein Binding). “Spanish” anesthetic (Articaine) has a marginally higher protein-binding capacity, which technically allows it to remain effective for a slightly longer period. However, in practical clinical reality, this difference isn’t substantial and often goes unnoticed.
6. In Surgeries… “Colombian” Shines!
This is where “Colombian” anesthetic truly demonstrates its strength.
What’s the Advantage? If you’re performing surgery and have raised a flap, you’ll undoubtedly notice the excellent hemostatic capabilities of “Colombian” anesthetic.
Why is That? This is because its epinephrine concentration is 1:80,000, which is higher than the 1:100,000 concentration found in “Spanish” anesthetic. A higher epinephrine concentration induces a stronger vasoconstriction, consequently reducing bleeding at the operative site quite remarkably.
7. Safety… Which is Safer for Whom?
-
Children: Both types are generally safe for pediatric patients, but it’s absolutely critical to precisely calculate the Maximum Recommended Dose (MRD) based on the child’s weight.
-
Pregnant Patients: Here, there’s a crucial distinction. “Colombian” anesthetic (Lidocaine) is considered completely safe for pregnant women, classified by the FDA as Category B for pregnancy. In contrast, “Spanish” anesthetic (Articaine) is categorized as C, meaning we prefer to use it with greater caution during pregnancy. Therefore, “Colombian” anesthetic stands out as the primary and safest choice for pregnant patients (1).
Critical Point: Usage Warnings (Never Overlook These!)
This particular point needs to be emphasized with a thousand underlines, as it directly impacts patient safety.
-
Cardiac and Hypertensive Patients: Due to the higher epinephrine concentration (1:80,000) in “Colombian” anesthetic, you must exercise extreme caution when using it with patients who have hypertension or any cardiovascular disorders.
-
Aspiration is Essential: You absolutely, positively must perform aspiration before injecting to ensure you are not within a blood vessel. Directly injecting epinephrine at this concentration into the bloodstream can lead to serious complications.
-
Maximum Dose: Be incredibly diligent about the number of cartridges used. The maximum recommended dose for a healthy adult is approximately 1.7 cartridges. This means if you administer two cartridges, you’ve already reached the patient’s Maximum Recommended Daily Dose (MRD). Never administer more than one and a half carpules in a single session unless you have calculated it with extreme precision (2).
In Summary: When to Use Which?
“Colombian” Anesthetic (Lidocaine 1:80,000):
-
Excellent for: Surgeries and extractions where optimal hemostasis is crucial.
-
The First Choice in: Cases involving pregnant patients.
-
Requires Extreme Caution with: Cardiac and hypertensive patients, and strict adherence to the maximum recommended dose (a maximum of 1.5 carpules in a typical session).
“Spanish” Anesthetic (Articaine 1:100,000):
-
Excellent for: Fillings and root canal treatments where high diffusion and profound anesthesia are needed.
-
Generally: Easier to inject and causes less discomfort for the patient.
-
Considered Safe for: Cardiac and hypertensive patients (of course, in reasonable doses) because its epinephrine concentration is lower.
Ultimately, there isn’t one anesthetic that is “superior” to the other in every single aspect. Each one is a tool with its own set of advantages and limitations. The truly skilled dentist is the one who knows precisely when and how to utilize each tool to achieve the best possible outcome with the highest degree of patient safety.
