Local aspirin analgesia in the oral cavity

Aspirin solution applied locally to the oral cavity produces an analgesic effect on pain induced by electrical stimuli and by knife prick. Spontaneous pain is also relieved. The effect is of a local nature and can be terminated by rinsing the mouth with water, indicating that there is only a loose bond between aspirin and the mucosa. The local nature is also demonstrated by the lack of analgesia in areas of the tongue where exposure to aspirin solution is prevented by separation with a rubber-dam.