Chapter 06 • Question 4
Why Do Dental Implants Fail?
📺 13:00 video📖 23 min read
Reviewed by Dr Tim Fleming
BDS – Dental Surgeon (GDC Reg: 83324)
Dental implants fail for different reasons depending on timing: early failures (first 3-4 months) are typically caused by failed osseointegration due to infection, insufficient bone quality, smoking, or surgical errors, while late failures (after 1+ years) are predominantly caused by peri-implantitis—gum disease around the implant resulting from poor oral hygiene. Other common causes include excessive forces from teeth grinding without a nightguard, premature loading before the implant has integrated, systemic factors like uncontrolled diabetes or heavy smoking, and occasionally mechanical issues like implant fracture or screw loosening.
💡 Key Takeaways
- Early failures (0-4 months) are primarily caused by failed osseointegration due to infection, insufficient bone quality, smoking, or surgical errors—accounting for 2-3% of implants
- Late failures (1+ years) are predominantly caused by peri-implantitis (80% of late failures)—gum disease around the implant from poor oral hygiene—and are largely preventable
- Smoking is the single biggest modifiable risk factor, causing early failure through impaired healing and late failure through accelerated bone loss and doubled peri-implantitis risk
- Poor oral hygiene is the underlying cause of most late failures—plaque accumulation leads to bacterial colonization, gum inflammation, bone loss, and eventual implant failure
- Teeth grinding (bruxism) without a nightguard creates excessive forces causing bone fatigue, progressive bone loss, screw loosening, and possible implant fracture
- Premature loading before osseointegration is complete (first 3-4 months) disrupts integration, allowing fibrous tissue instead of bone and preventing successful fusion
- Uncontrolled diabetes (HbA1c >8%) severely impairs healing and bone integration, while well-controlled diabetes has minimal impact—control is key, not diagnosis
- Inadequate bone assessment or skipping necessary bone grafting creates unstable foundations leading to failed integration and early implant loss
- Peri-implantitis develops in stages from reversible gum inflammation to irreversible bone loss—early detection through 6-month professional cleanings is critical
- Bone overheating during drilling (>47°C from inadequate irrigation) kills bone cells and prevents osseointegration—proper surgical technique is essential
- Systemic health deterioration after implant placement (diabetes worsening, starting immunosuppression, resuming smoking) can cause late failure years after successful integration