Intravenous sedation was used for dealing with transient hypertension, so-called white-coat hypertension, before dental treatment. Midazolam used as a sedative also has antianxiety effect, and the mechanism is guessed that it minimizes patients' stress, resulting in the stability of blood pressure. The purpose of this randomized controlled trial (RCT) is to evaluate the effect of low dose of midazolam on blood pressure and anxiety scale in white-coat hypertensive dental patients.