This article discusses the issues of benefit and possibility of application of patient-controlled sedation (PCS) for the dental treatment. The purpose of administering PCS for patients is to diminish anxiety and to provide cooperative and effective dental treatment. But there are a lot of barriers to application of PCS such as knowledge about pharmacokinetics of sedatives, expensive high speed and patient-controllable syringe pump, and well educated sedationist. And there could be risk of deep sedation, airway obstruction and hypoxic brain damages, etc. In order to decrease incidence of complication, appropriate drug selection, selection of right bolus dose, lock-out time is much important.