What is the MOST significant factor compromising implant survival?

Correct answer: B. Tobacco use (smoking)

• A. Incorrect. Uncontrolled diabetes is a systemic risk factor, but controlled diabetes has much less impact. Smoking consistently ranks as the primary behavioral risk factor.
• B. Correct. TOBACCO/SMOKING is the single most significant risk factor for implant failure. Smoking impairs angiogenesis, reduces tissue oxygen tension, impairs immune response, and decreases osseointegration. Smokers have implant failure rates 2–5× higher than non-smokers.
• C. Incorrect. Bruxism creates excessive occlusal loading and is a risk factor, but is not the single most commonly cited compromising factor.
• D. Incorrect. Poor oral hygiene leads to peri-implantitis — an important cause of late implant failure, but smoking is the most significant single risk factor.