Dental treatment under general anesthesia is considered for behavioral control of disabled patients who have severe anxiety or involuntary movement. However, in case of simple treatment, inhalation or intravenous sedation, which has earlier onset and recovery, is preferred. Conventionally, nitric oxide is used for inhalation sedation, nowadays sevoflurane can also be used due to easily titratable for controllable effect and less complications. In this case report, two patients with mental retardation required simple dental treatment. Deep sedation with inhaled sevoflurane were successfully employed and patients were discharged without any complications.