Implant surgery is performed in patients with a wide age range, including elderly patients with hypertension. Dentists or oral surgeons often encounter hypertensive patients who are undiagnosed or noncompliant. Among Japanese over the age of 30, 60% of men and 44.6% of women suffer from high blood pressure, and 33.8% of men and 25.6% of women with a history of hypertension have not been managed medically [20]. In this study, though 13 of the patients did not have a history of hypertension, they were diagnosed with essential hypertension by a physician because they had high blood pressure before surgery. Among patients with a history of high blood pressure, 31 patients (29%) showed high blood pressure before surgery. Because there are many of dental patients with undiagnosed or noncompliant hypertension, blood pressure measurement before treatment, particularly invasive surgery, is indispensable.

For dental implant surgery in hypertensive patients who are not adequately controlled, the application of intravenous sedation and preoperative antihypertensive medication would be useful in order to prevent perioperative hypertension crisis including hypertension emergency with end-organ damage or hypertension urgency without end-organ damage. Since sublingual administration of immediate-release (IR) nifedipine may cause side effects such as significant decrease in blood pressure, reflex tachycardia, and acute myocardial infarction [21], the sublingual administration of IR nifedipine to hypertension crisis has not been approved by the Food and Drug Administration (1985) and Japanese Society of Hypertension Guidelines for the Management of Hypertension (2000). Since we could manage patients with high blood pressure without any cerebrovascular complications by oral administration of nifedipine under closely monitoring, it may be concluded that preoperative administration of oral nifedipine to patients with high blood pressure may be effective to prevent hypertensive crisis due to sudden rise in blood pressure during surgery. Further studies are necessary to evaluate the usefulness of captopril, clonidine, and labetalol, which have been reported as alternatives to nifedipine in emergency hypertension [22-24] in patients with high blood pressure.