Blood pressure monitoring is a standard safety measure in modern dental practice. The oral cavity is highly vascularized, making blood flow stability important during procedures, especially those involving local anesthesia or surgery. A spike in blood pressure during treatment increases the risk of adverse cardiovascular events, such as a stroke or heart attack. Dentists measure blood pressure to establish a baseline and screen for undiagnosed hypertension, which is often asymptomatic. Readings may also be temporarily elevated due to anxiety, a phenomenon called “white coat syndrome.”
Defining the Risk Thresholds
Dental professionals classify blood pressure readings using established medical guidelines. A reading below 120 systolic and 80 diastolic millimeters of mercury (mmHg) is considered normal. An elevated reading falls between 120–129 mmHg systolic and less than 80 mmHg diastolic.
Stage 1 Hypertension is classified when the systolic number reaches 130–139 mmHg, or the diastolic number is 80–89 mmHg. Stage 2 Hypertension is categorized by readings of 140 mmHg systolic or 90 mmHg diastolic or higher. The most concerning classification is a hypertensive crisis, defined by a systolic reading of 180 mmHg or higher and/or a diastolic reading of 110 mmHg or higher. The threshold for postponing elective treatment is often set at a systolic reading greater than 160 mmHg or a diastolic reading greater than 100 mmHg.
Immediate Clinical Response and Treatment Delay
When a patient has an initial reading above the normal range, the dental team follows a protocol to ensure accuracy. The first step involves having the patient rest quietly for approximately five minutes before taking a second measurement. This allows the patient to acclimate and often rules out a temporary spike from physical exertion or anxiety. If the second reading remains high, the urgency of the planned treatment is determined.
For elective procedures, such as a routine cleaning or cosmetic filling, treatment is typically deferred if the blood pressure is significantly elevated (e.g., above 180/110 mmHg). Deferral avoids the heightened risk of a serious cardiovascular event triggered by procedural stress. If the patient has an acute infection or severe pain constituting an emergency, the dental team may proceed with limited, conservative care, provided the blood pressure is below the 180/110 mmHg crisis level. In urgent cases, the patient’s blood pressure is monitored frequently throughout the procedure, often every 10 to 15 minutes, and anxiety reduction techniques may be employed.
Modification of Dental Treatment
If the dental procedure moves forward, the dentist will often modify their technique, particularly concerning the use of local anesthesia. Most local anesthetics used in dentistry contain a vasoconstrictor, usually epinephrine. This compound constricts local blood vessels, which keeps the anesthetic concentrated for prolonged numbness and reduces bleeding during the procedure.
For a patient with uncontrolled hypertension, the systemic absorption of epinephrine can cause a transient increase in both blood pressure and heart rate. To mitigate this risk, the dentist may limit the total dose of epinephrine administered. Guidelines generally suggest restricting the total amount of epinephrine to a small dose, often corresponding to only a few cartridges of local anesthetic.
Dentists may also modify the type and concentration of the anesthetic solution used. They might opt for a lower concentration of epinephrine, such as a 1:200,000 solution instead of the 1:100,000 concentration. Alternatively, the procedure may be performed using an anesthetic that contains no vasoconstrictor at all. The injection technique is also modified to include slow administration and aspiration before injection, which minimizes the chance of the solution entering a blood vessel directly.
Follow-up and Coordination with Primary Care
An elevated blood pressure reading taken in the dental office primarily functions as a health screening and awareness measure. The role of the dentist is not to diagnose or manage chronic hypertension, but rather to identify a potential health concern. If a patient has an unexpected or significantly high reading, the dental team will inform them of the results and the potential health implications.
The patient is advised to schedule a follow-up appointment with their primary care physician (PCP) for a comprehensive medical evaluation. The dentist should communicate the specific reading to the PCP, ideally through a referral form, to ensure continuity of care. This coordination is important because a diagnosis of hypertension requires multiple elevated readings taken on different occasions, not just a single measure in the dental chair. Patients who do not have a PCP may be provided with resources to find a medical professional who can manage their systemic health.