The success rate of dental implants is 90%. Failure usually occurs during the second surgery, when the surgeon discovers that the implant is loose and failed to integrate with the jaw bone. The loose implant is removed and another implant can be placed. Implants usually fail due to infection, surgical trauma, titanium allergies, smoking (which decreases blood flow to the healing gums), and lack of healthy bone (if jaw bone is too small for the implant to stay put, bonding will not happen).
Problems may also arise years after getting dental implants. Gums can get infected bacteria, which leads to a disease called perimplantitis. If untreated, this disease can cause bone loss and also loosens the implant. Another problem that can happen is when the denture itself breaks. This usually occurs when your bite is not aligned properly, putting too much force on the implant. The broken denture can be repaired or removed and replaced.