Although dental implant placement is one of the most effective ways to replace missing teeth, there are cases in which this procedure cannot be performed. Dental implantation requires surgical intervention, and there are several general contraindications to this procedure.
Why might dental implant surgery not be recommended?
Contraindications can be absolute, relative, or temporary.
Absolute contraindications mean that the procedure cannot be performed at all.
Relative contraindications mean that implantation may be performed with caution after treating certain conditions.
Temporary contraindications indicate that the procedure should be postponed.
Absolute contraindications to dental implants include:
Diseases of the blood and hematopoietic system.
For example, blood clotting disorders make any surgical procedure impossible due to the risk of severe bleeding.
Diseases of the central nervous system (both congenital and acquired).
A clear example is a mental disorder in which the patient is unable to adequately understand and follow instructions and behavioral rules during treatment.
Immunopathological conditions. Dental implant placement is not possible if a patient has an immune disorder. This is a common contraindication for many surgical procedures. The immune system is responsible for the body’s recovery after surgery and prosthetic treatment. If the immune system does not function properly, implantation becomes risky. Surgical intervention requires a certain period of active and intense immune response for normal tissue healing after surgery.
Systemic connective tissue diseases. Implantation requires the growth and development of connective tissue around the implant; therefore, diseases such as systemic lupus erythematosus, scleroderma, and rheumatic diseases make implant placement impossible.
Poorly controlled diabetes mellitus. When blood glucose levels rise sharply, bone healing occurs very slowly, and there is a significant risk of postoperative infections. Such patients are poor candidates for dental implantation.
Alcoholism and drug addiction. Alcoholism is not only a systemic dysfunction of all organs and systems but also a cause of noncompliance with treatment regimens, poor oral hygiene, improper nutrition, and other factors. In these cases, the patient is close to having an absolute contraindication to dental implantation, as postoperative complications and delayed medical attention may pose a life-threatening risk. Drug addiction carries risks similar to alcoholism but with even more severe consequences and is considered an absolute contraindication to dental implantation.
Certain medical treatments that may affect healing and implant retention in surrounding tissues
(for example, the use of immunosuppressants, anticoagulants, antidepressants, cytostatics, and other substances).
Relative Contraindications
Osteoporosis. Previously considered an absolute contraindication, current statistics have disproven this. The real cause of increased risk during dental implantation is the use of antiresorptive medications (bisphosphonates). Osteoporosis is a relative contraindication and requires consultation with a physician, who may decide to reduce the dosage or temporarily discontinue medication. Timing is crucial, as these drugs tend to accumulate in bone tissue.
Poor dental health, such as the presence of carious teeth. Implantation is possible after appropriate dental treatment.
Poor oral hygiene. A patient’s refusal to follow a dentist’s oral care recommendations may also be a contraindication. In severe cases, when the dentist cannot educate or persuade the patient, implantation may be postponed. However, behavior may change over time, independently or with the help of psychotherapy or a dental hygienist.
Gingivitis (inflammatory conditions of the gums, infectious or non-infectious). Requires prior treatment and oral sanitation.
Periodontitis — inflammation of the tissues surrounding the teeth. Initial treatment includes controlling inflammation, strengthening the gums, bone augmentation if necessary (bone grafting), and the use of special implants (e.g., short implants), as periodontitis causes bone loss and increases the risk of infection.
Pathological malocclusion. Orthodontic treatment is required prior to implantation.
Bone atrophy or bone defects. Bone grafting is required.
Diseases affecting treatment compliance and oral hygiene. These include neurological disorders ranging from schizophrenia to Down syndrome. Such conditions are not always contraindications. There is sufficient statistical evidence of successful dental implantation in these patient groups. Each case should be evaluated individually. These patients may be considered candidates if there is someone who can assist with implant care.
Distress syndrome (severe and prolonged stress).
Cachexia (severe physical exhaustion).
Temporary Contraindications
Pregnancy. There is a list of dental procedures that can be performed during pregnancy; however, implantation is best postponed until after childbirth. This is due to the need for computed tomography and extensive surgical intervention requiring strong anesthetics and, in some cases, additional drug therapy.
Age. Dental implants are not recommended for patients under 16 years of age. The jawbone structure in children and adolescents may not yet be fully developed, which can lead to implant-related problems later. The jaw must be fully developed to successfully support implants.
Radiation therapy. Patients with cancer or those who have undergone radiation therapy within the past five years are usually not candidates for dental implants. Radiation exposure may affect titanium materials used in implants. Alternative tooth replacement options should be considered, or implantation postponed until deemed acceptable by a dentist or physician.
The good news is that over time, especially during stable remission, the risk of complications decreases. Therefore, radiation therapy may be considered a relative contraindication to maxillofacial surgery.
Why Is It So Important to Take a Patient’s Medical History Before Surgery?
In most cases, dental implantation and restoration are required by patients aged 50 and older, many of whom have conditions such as hypertension or diabetes. It is essential to thoroughly assess their lifestyle and the medications they take regularly. Patients should consult their physician and should not independently alter, reduce, or discontinue medications. Only the treating physician should make such decisions and must be informed about the planned implantation.
Before the procedure, the dentist must interview the patient and review their medical documentation. Patients are not specialists and may not accurately assess their condition or may fail to report important details due to lack of knowledge or perceived irrelevance. Detailed medical history is essential before developing a treatment plan and scheduling implantation surgery. Particular attention should be paid to factors affecting bone healing. Implant placement followed by abutment and crown installation is a complex process, and a high risk of implant rejection may lead to osteonecrosis (aseptic or avascular bone necrosis) and other life-threatening complications.
Key Factors to Assess Before Implantation:
- risk of impaired blood clotting and postoperative bleeding, or conversely, the risk of thrombosis and thromboembolism;
- changes in hemostasis due to medication use;
- the bone’s ability to heal under the patient’s current condition;
- susceptibility to infection and ability to resist it;
- patient’s stress tolerance and resilience.
Modern anesthesia can completely eliminate pain; however, patients often experience significant anxiety before implantation. Psychological state affects blood pressure, heart rate, and even postoperative healing.
| Designation | Patient Condition | Indications / Contraindications | Notes |
| ASA I | Healthy patient | Maxillofacial surgery can be performed without additional precautions; not contraindicated | It is important to determine whether the patient has any allergic reactions to substances that will be used during the procedure |
| ASA II | Mild systemic disease | Dental implant surgery is not contraindicated provided that the underlying condition (e.g., diabetes, hypertension, asthma, epilepsy) is carefully controlled or stabilized | This group also includes smokers who smoke 10 or more cigarettes per day, as well as patients with stage I hypertension, mild obesity, mild diabetes, etc. |
| ASA III | Severe systemic disease | Dental implantation is not contraindicated only after consultation with a physician and when the patient’s condition is stably compensated with medication | Includes patients with controlled hypertension, moderate insulin-dependent diabetes, and mild chronic obstructive pulmonary disease (COPD). Also includes patients who had myocardial infarction, cerebrovascular disease, or congestive heart failure more than 6 months ago |
| ASA IV | Severe systemic disease posing a constant threat to life | Very rarely, these patients may be candidates for elective oral surgery. Implantation must be performed only in a hospital setting | Includes patients with uncontrolled hypertension, diabetes, or epilepsy; moderate to severe COPD; unstable angina; myocardial infarction within the last 6 months; cerebrovascular disorders; or congestive heart failure |
How Do Medications Affect Dental Implantation?
It is crucial to understand how long-term medications affect local and systemic bone healing, surgical complexity, and interactions with perioperative drugs.
- Antiresorptive drugs, particularly high-dose bisphosphonates, used for osteoporosis, metastases, multiple myeloma, etc. These patients have a higher risk of implant loss and osteonecrosis. These drugs accumulate in bone with a long half-life (over 10 years). High doses and long-term use are absolute contraindications to maxillofacial surgery.
- Immunosuppressive drugs, used in cancer treatment, chemotherapy, organ transplantation, and high-dose corticosteroids, increase the risk of postoperative infections and implant loss. High doses are absolute contraindications. After treatment completion and immune recovery, patients may exit the high-risk group.
- Antithrombotic therapy, commonly prescribed for cardiovascular diseases, increases the risk of postoperative bleeding. Therapy adjustments may be possible, but medications should never be discontinued independently. Oral bleeding is easier to manage than thromboembolism, which may occur after stopping therapy. Many of these drugs are incompatible with antibiotics and NSAIDs and must be carefully reviewed with a specialist.
How Common Is Titanium Allergy in Dental Implants?
This is one of the most frequently asked questions. Fortunately, true titanium allergy is extremely rare. Documented cases are exceptionally few. The likelihood is comparable to developing an allergy to air. Most suspected “titanium allergies” are actually misdiagnosed complications of other origins (peri-implantitis, mucositis, etc.). Titanium, usually in the form of titanium dioxide, is widely used, and we encounter it daily in products ranging from pigments to sunscreens.
Is Dental Implantation the Right Choice?
Would you like to learn more about contraindications to dental implants? Although many common contraindications are listed in this article, it is best to consult a specialist regarding potential patient-specific issues. A dental surgeon will review your medical history, assess oral health, and provide personalized advice on whether implantation is a suitable option for you.
Book an appointment at YAREMA DENTAL Clinic, where experienced specialists will answer all your questions.
This article does not replace a medical consultation. For complete and personalized information, please consult your dentist.