Local anesthetics are substances which, by local action groups on the runners, cause loss of reversible a painful sensation, delimited corresponding to the application. They allow small surgery, short in duration and the endoscopic maneuvers. May be useful in soothe teething pain of short duration and in the locking of the nervous disorders in medical care. Local anesthesia is a process useful for the carrying out of surgery and of endoscopic maneuvers, to soothe teething pain in certain conditions, for depriving the temporary structures peripheral nervous control. Reversible locking of the transmission nociceptive, the set of the vegetative and with a local anesthetic at the level of the innervations peripheral nerve, roots and runners, a trunk nervous, around the components of a ganglion or coolant is cefalorahidian practice anesthesia loco-regional. Local anesthetics summary and semi-summary have multiple applications in dentistry, consulting, surgery and obstetrics, constituting "weapons" very useful in the fight against the pain.