Recently, sedation in dentistry is gaining more and more interests of dental practitioners. Moreover, "dental sedation", "sleep dentistry", or "pain-free dental treatment" become everyday words familiar to ordinary persons. Sedation clinic in Hanyang University Medical Center was open on Mar 2006 as specialty clinic at department of dentistry. Our aim is performing comfortable and safe dental treatments for patients who have problems for routine dental treatments because of extreme fear and anxiety or for patients who are supposed to have stressful and painful time-consuming treatment, such as sinus elevation and bone graft for implant placement. Our sedation was focused on conscious sedation, especially intravenous sedation using midazolam alone in technique. In two series, the sedation protocol at our Sedation Clinic will be described in details and then, analysis of our cases will be presented to help beginners for sedation in dentistry.