The pharmacological properties of LAs vary from agent to agent. To compensate for these differences, manufactures have adjusted the concentration of various LAs such that they all produce nearly the same effect. Consequently, the LA selected in each clinical situation and the dosage administered should be predicated on potential toxic and other ADEs. In most instances, lidocaine 2% w/epinephrine 1:100,000 is as effective as, and less toxic than, other agents.

Infiltration anesthesia with lidocaine 2% w/epinephrine 1:50,000 may be useful to provide surgical hemostasis. Mepivacaine 3% plain provides for longer duration of action than lidocaine 2% plain and it is a good option when the use of a vasoconstrictor is contraindicated. Infiltration anesthesia with articaine 4% w/epinephrine 1:100,000 may provide for a greater probability of achieving pulpal anesthesia with longer duration in comparison to lidocaine 2% w/epinephrine 1:100,000.

Bupivacaine, because of its high lipid solubility and high protein-binding capacity, produces the longest duration of pulpal anesthesia. This may be useful for lengthy procedures. However, because it will also produce prolonged soft-tissue analgesia, it should be used with caution in the elderly and the debilitated to minimize self-mutilation; and its use in patients younger than 12 years of age is not recommended. Bupivacaine is also the most cardiotoxic of all LAs.

The use of epinephrine with LAs is standard dental practice. The question to ask is not whether epinephrine should be used – the question to ask is how much epinephrine can be used safely. To minimize serious medication errors, think of dosage strengths of epinephrine in mg/mL of LA rather than ratio expressions (e.g., 1:100,000). In general, the MRD of epinephrine with LAs for healthy adults is 0.2 mg per visit; in high-risk populations, 0.02 to 0.05 mg is recommended. chat Let's get started!