The primary aim of this study is to investigate if AZD1386 can relieve the pain induced by the surgical removal of one lower wisdom-tooth. This will be done by comparing the effect of AZD1386 to placebo ("inactive substance") on pain. A number of patients will instead receive the common painkiller naproxen for comparison purposes. Rescue medication, acetaminophen, will be allowed if a need for additional painkillers would arise. A number of patients will receive naproxen as control.