Dental implants are titanium posts placed into the jawbone that function as artificial tooth roots, providing a durable foundation for replacement teeth. The titanium material fuses directly with the bone through a process called osseointegration, making implants a highly successful, long-term solution for missing teeth. However, not everyone is eligible for the procedure, as success depends heavily on specific oral health, anatomical, and systemic factors.
Foundational Oral Health Prerequisites
The implant site must be healthy; active disease is a barrier to treatment. Untreated periodontal disease (gum disease) is concerning because the bacterial infection destroys the underlying bone and soft tissue. Placing an implant into an infected area significantly increases the risk of peri-implantitis, which can lead to implant failure.
Any existing oral infections, such as abscesses or large, untreated cavities, must be resolved before surgery. These conditions create an inflammatory state hostile to the healing required for osseointegration. Addressing these issues, often through professional cleaning or antibiotic therapy, may make a patient temporarily ineligible until the infection is cleared and health is stable.
Jawbone Density and Structure Requirements
The quality and quantity of the jawbone determine if an implant can be successfully placed and stabilized. Implants require sufficient bone volume, typically 6 to 10 millimeters in height and 6 to 8 millimeters in width, to fully encase the titanium post. Without this adequate support, the implant lacks the primary stability needed to withstand chewing forces and fuse with the bone.
Bone quality is categorized, with denser types (D2 and D3) being most favorable for osseointegration. Very dense bone (D1) can slow healing due to reduced blood flow, while soft, porous bone (D4) may lack initial stability. Anatomical structures also limit placement; for example, the maxillary sinuses may encroach on bone height in the upper jaw. In the lower jaw, the position of the inferior alveolar nerve dictates the necessary bone height to prevent impingement.
Systemic Health Conditions Affecting Success
Systemic health plays a role in the body’s ability to heal and integrate a dental implant. Chronic conditions can compromise osseointegration, the fusion of the implant with the bone. Uncontrolled diabetes is a major concern because high blood sugar levels impair blood circulation, slowing healing and increasing the risk of post-surgical infection and failure.
Autoimmune disorders and immunosuppressive therapy can also affect healing capacity and raise complication risks. Patients with a recent history of heart attack or stroke require medical clearance before elective surgery. Certain medications, particularly bisphosphonates used for osteoporosis, interfere with bone turnover and risk a serious complication called osteonecrosis of the jaw.
Lifestyle choices are also assessed, as heavy smoking and tobacco use pose a threat to implant success. Smoking restricts blood flow and oxygen delivery to the surgical site, impairing natural healing mechanisms. Patients are often required to discontinue tobacco use completely before and immediately after the procedure to improve candidacy.
The Pre-Surgical Assessment Process
Determining eligibility requires an evaluation conducted by the dental professional. This process begins with a comprehensive review of the patient’s medical and dental history to identify systemic conditions, medications, or prior oral health issues that pose a risk. A clinical oral examination assesses the health of the gums and remaining teeth, looking for signs of active infection or inflammation.
The assessment involves advanced imaging of the jaw’s anatomical structures. Cone-Beam Computed Tomography (CBCT) is the standard technique, providing a three-dimensional view of the bone structure. The CBCT allows the clinician to precisely measure the height, width, and density of the available bone at the implant site. It also maps the location of sensitive structures, such as the maxillary sinuses and the inferior alveolar nerve, ensuring the surgical plan avoids these areas for a safer outcome.
Pathways to Potential Eligibility
Initial findings of ineligibility do not necessarily end the implant journey. Many common reasons for exclusion can be managed or corrected through preparatory procedures and medical stabilization. For example, insufficient jawbone volume can be overcome using various bone grafting techniques.
Bone grafting involves placing material—sourced from the patient, a donor, or synthetic materials—into the deficient area to stimulate new bone growth. A specific technique, the sinus lift, is performed when upper jaw bone height is inadequate due to the maxillary sinus proximity. This procedure raises the sinus floor and places graft material beneath it, creating the necessary vertical bone dimension. Patients with systemic conditions like uncontrolled diabetes can also gain eligibility by stabilizing their condition and achieving controlled blood sugar levels.