What is the purpose of adding a vasoconstrictor to local anaesthetics?

Adding a vasoconstrictor to local anaesthetics serves the primary purpose of prolonging the duration of anaesthesia. The vasoconstrictor, like epinephrine, works by constricting blood vessels in the area where the anaesthetic is administered. This reduces blood flow, which slows the absorption of the anaesthetic into the bloodstream. Consequently, the local anaesthetic remains in the area longer, allowing for extended pain relief during dental procedures.

This mechanism not only enhances the effectiveness of the anaesthetic but also limits the potential for systemic side effects by reducing the quantity of the drug that enters the circulation. Therefore, the use of a vasoconstrictor is a crucial aspect in optimizing the effectiveness and safety of local anaesthesia in dental practice.