For minor surgeries like dental procedures, local anaesthesia is considered to be very safe. Temporary effects may include Bruising
Headache, dizziness and nausea
Tingling Having said that, a study quoted by the American Association of Oral and Maxillofacial Surgeons found that only 6% out of 34,000 patients who were administered anaesthetic had minor side effects. Only a small percentage of patients experienced prolonged or permanent numbness. Therefore, anaesthetic is generally considered safe.