General Medicine and General Surgery Relevant to Dentistry
This domain asks whether a dental procedure is safe today, what must be modified, and what to do if a medical emergency occurs in the chair. Cardiovascular disease, diabetes, anticoagulation, antibiotic prophylaxis and emergency management carry most of the marks.
Cardiovascular disease
- Defer elective treatment when blood pressure exceeds about 180/110 mmHg and refer for control.
- Infective endocarditis prophylaxis is now limited to high-risk cardiac conditions (prosthetic valve or material, previous endocarditis, unrepaired cyanotic congenital disease); a single 2 g dose of amoxicillin 30-60 minutes preoperatively is standard, with azithromycin or doxycycline for penicillin allergy. Clindamycin is no longer recommended because of resistance and colitis.
- Continue warfarin with a checked INR (simple extractions are acceptable around 3.5 or below) using local haemostatic measures; for direct oral anticoagulants, timing modification is preferred to stopping the drug outright, and antiplatelet therapy is never stopped without cardiology advice.
- Limit epinephrine in cardiac patients to roughly 0.036 mg, about two cartridges of 1:100,000, and avoid it entirely in unstable angina or uncontrolled thyrotoxicosis.
Endocrine and pregnancy
- Diabetic patients: morning appointments, confirm recent food intake, keep glucose available, and expect delayed healing and greater infection risk when HbA1c is high.
- Suspected hypoglycaemia presents with sweating, tremor and confusion; give oral glucose if conscious.
- The second trimester is the preferred period for elective care; avoid the supine hypotensive position and use abdominal shielding for essential radiographs.
Emergencies and surgical principles
- Syncope: supine with legs raised and airway maintained.
- Anaphylaxis: intramuscular epinephrine 0.5 mg of 1:1000 into the anterolateral thigh, oxygen and call for help.
- Biopsy technique: incisional for large or suspicious lesions, excisional for small discrete ones, always with histopathology.
Worked example
A patient on warfarin with an INR of 3.2 needs a single extraction. The correct answer is not to stop warfarin, but to proceed with a check INR, atraumatic extraction, local haemostatic measures such as sutures and tranexamic acid mouthwash, and clear written post-operative instructions.
Traps
- Stopping anticoagulants without medical consultation.
- Prescribing clindamycin for endocarditis prophylaxis.
- Using epinephrine freely in a patient with unstable cardiac disease.