What is the duration of 0.5% bupivacaine with a 1 to 200,000 ratio of epinephrine?

The duration of 0.5% bupivacaine when combined with epinephrine at a ratio of 1 to 200,000 typically ranges around 6 to 8 hours. Bupivacaine is a long-acting local anesthetic, and the addition of epinephrine serves to prolong its action by causing vasoconstriction, which decreases the rate of systemic absorption and enhances the duration of the anesthetic effect.

This lasting effect is particularly beneficial in dental practices where longer procedures may be conducted, allowing patients to remain comfortable without needing additional doses during treatment. The specific duration can vary based on individual patient factors and the exact procedure but generally falls within this extended time frame due to the properties of both the local anesthetic and the vasoconstrictor used.