Dental implants have unparalleled advantages in restoring teeth, and the scope of restoration is relatively wide, with almost no restrictions on age. So, what are the contraindications of dental implants? 1. Hypertension All dental implant patients should have their blood pressure measured, especially those who have been diagnosed with hypertension. For patients with mild hypertension, implant restorative treatment can be performed, but local anesthetic drugs without epinephrine should be chosen during the operation to avoid elevated blood pressure, while making the operation completely painless and shortening the operation time. For patients with severe hypertension (systolic blood pressure ≥ 180 mmHg, diastolic blood pressure ≥ 110 mmHg), internal medicine consultation should be conducted to control the blood pressure within the range of normal or mild hypertension before the operation. 2, angina Mild angina patients should be routinely prepared with nitroglycerin and oxygen during implant surgery, and vital sign testing should be performed when the surgery takes longer or is more complicated. For severe angina pectoris with almost daily attacks or unstable angina pectoris with frequent attacks within 60 days, postpone the implantation surgery. 3. Myocardial infarction In patients with a past history of myocardial infarction, special attention should be paid to the time of onset of the last heart attack. Only some simple and acute treatment can be performed 6-12 months after the onset of the disease. The Shanghai Mouth Medical Platform recommends that those who have had the onset of the disease for more than 12 months should be hospitalized for surgery as much as possible and undergo as simplified treatment as possible after the consent of the internal medicine consultation. 4. Diabetic patients with blood sugar control below 150mg/dl can undergo surgery, but they need to pay attention to diet adjustment before and after surgery and prevent postoperative infection. Shanghai mouth doctor suggests that for patients with severe diabetes (blood sugar >200mg/dl), surgery can only be performed after blood sugar control. 5. Hyperthyroidism Patients with hyperthyroidism can undergo implant surgery if the indicators of laboratory tests are normal within six months and if they do not have any clinical symptoms. If there are clinical symptoms of hypermetabolic syndrome, neurological and cardiovascular abnormalities, postpone the implantation surgery. 6. Adrenal gland disease For patients at mild risk who have been treated with corticosteroid replacement therapy on alternate days or who have been off the medication for more than a year, surgery can be scheduled on the day of medication, and colleagues are sedated and given effective antibacterial medication. Patients taking prednisone > 5 mg daily, postpone implant surgery. 7. Pregnancy Postpone implant surgery until after pregnancy and delivery. 8. Anemia If the systemic symptoms are severe or if the hemoglobin is <10mg/dl, postpone the implant surgery. 9, blood cell disease Malignant diseases, such as acute and chronic leukemia caused by increased or decreased white blood cells are contraindications to implant restoration. 10. Chronic obstructive disease Dyspnea or pulmonary infection or severe pulmonary impairment even at rest, oxygen saturation <90, postpone implant surgery. 11, chronic liver disease Chronic active hepatitis, cirrhosis of the liver in the decompensated stage, postpone implantation surgery. 12, radiotherapy The time of implantation surgery after radiotherapy should be postponed as much as possible. 13.Patients taking long-term medication Patients taking long-term oral diphosphonates for osteoporosis should stop taking the medication for several months before implantation, especially those taking oral best-selling preparations, some scholars believe that the medication should be stopped for more than six months, otherwise there is a risk of causing osteomyelitis of the jaw. The indications and contraindications for dental implants are not absolute, so it is recommended to go to a regular dental hospital for a professional examination and a reasonable treatment plan by an oral surgeon to determine if you are suitable for dental implants.