How many mg of anesthetic is in a dental cartridge of 3% mepivacaine?

A dental cartridge typically contains 1.8 mL of solution. To calculate the amount of anesthetic in a cartridge of 3% mepivacaine, you need to understand that "3%" refers to the concentration of the drug in the solution, indicating that there are 3 grams of mepivacaine in every 100 mL of solution.

To convert this concentration to milligrams per milliliter, note that 3 grams is equivalent to 3000 mg. Therefore, a 3% solution has 30 mg of mepivacaine in 1 mL (since 3000 mg in 100 mL means 30 mg/mL).

When you multiply the concentration of 30 mg/mL by the volume of the cartridge (1.8 mL), you get:

30 mg/mL x 1.8 mL = 54 mg.

This calculation confirms that there are 54 mg of mepivacaine in a dental cartridge of 3% mepivacaine, making this the correct answer to the question.