A retrospective review of the clinical records was conducted for 336 patients who received dental implant-related surgeries combined with intravenous sedation between January 2008 and February 2012 at our outpatient dental offices. Among the patients, 125 patients received multiple surgeries during the observation period: 4 patients underwent surgery five times, 7 patients four times, 29 patients three times, 85 patients twice, and others once. The following surgical procedures were performed in a total of 516 patients: dental implant placement (466 patients), sinus lift surgery and dental implant (28 patients), socket lift and dental implant (10 patients), and guided bone regeneration and dental implant (12 patients).

We performed surgeries after medical consultation when patients had a history of hypertension or cardiovascular or cerebrovascular diseases. History of ischemic heart disease, renal dysfunction, diabetes mellitus, cerebral infarction, or articular rheumatism was documented in 17 patients in the hypertensive group and 16 patients in the normotensive group. They were confirmed stable and well controlled for implant surgery. For patients who received therapeutic drugs, surgery was performed following daily medication.

The patients were allowed to have water or snacks until 2 h before the visit. On arrival at the office, systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse rate (PR) were measured using an automatic blood pressure monitor with an oscillometric method (HEM-1010, Omron Healthcare, Kyoto, Japan). The cephalic vein was cannulated with a 22-G disposable intravenous catheter. Nifedipine capsule (10 mg) was orally administered to patients with sustained increases in SBP ≥160 mmHg for 30 min from baseline measurement. A noninvasive blood pressure monitoring system with electrocardiogram (ECG) monitor and pulse oximeter (Moneo BP-88, Omron Healthcare, Kyoto, Japan) was mounted, and blood pressure was measured at 2- to 5-min intervals. In patients with a history of cardiovascular disease, ECG was continuously monitored. Following confirmation of a definite decline of blood pressure or SBP <160 mmHg, infiltration anesthesia and/or conduction anesthesia was administered using 1 to 3 cartridges (1.8 to 5.4 ml) of 2% lidocaine containing 1/80,000 epinephrine.