How much local anesthetic is present in a 0.5% dental cartridge (1.8 ml cartridge)?

To determine the amount of local anesthetic in a 0.5% solution within a 1.8 ml cartridge, it's essential to understand the concentration percentage. A 0.5% solution means that there are 0.5 grams of the anesthetic in 100 ml of solution. To convert this to milligrams, 0.5 grams is equivalent to 500 mg.

Next, we calculate how much anesthetic is present in a 1.8 ml cartridge. Since there are 500 mg in 100 ml, we can find the concentration in 1.8 ml by setting up a proportion:

500 mg / 100 ml = X mg / 1.8 ml

By cross-multiplying and solving for X, you would get:

X = (500 mg * 1.8 ml) / 100 ml = 9 mg

Thus, the amount of local anesthetic present in a 0.5% solution in a 1.8 ml cartridge is 9 mg. This calculation shows how concentration works in conjunction with volume, helping to illustrate the relationship between percentage solution and the actual quantity of anesthetic in a specific volume.