Objective:The purpose of this study was to evaluate the clinical effects of patient-controlled sedation during the extraction of impacted tooth.Methods:The patient-controlled sedation with propofol was compared to non-sedation, in a randomized crossover study of 22 outpatients undergoing two-stage bilateral extraction of impacted third molar teeth under local anesthesiawith 2% Lido- caine. Cardiovascular and respiratory stability and the effects of sedationwere observed; postoperative memory was measured with delayed free recall.Results:The blood pressure and heart rates were stable and showed no difference in Group P and Group L(P >0105). Haemoglobin oxygen saturationwasmaintained at a level of 97% orhigherfor all patients. Sedationwas no deeperthan 3 Ramsy scores. Intra-operative patient cooperation, postoperative patient satisfaction and surgeon satisfaction in group P were higher than those in group L(P
