The success rate for dental implants is very high. According to the most recent research, the overall success rates in natural bone is 95%, though this falls to between 85% and 90% in grafted bone.
Of course, given the above percentages it should be clear that dental implants can fail, albeit infrequently. Failure rates vary depending on the site in the mouth, whether they are placed into natural or grafted bone and whether the patient smokes. If a patient smokes it has been shown that they are statistically two and a half times more likely to have an implant fail than a non-smoker.
Though many factors our outside our control, you can take certain steps to ensure a successful treatment. Specifically, you should maintain meticulous oral hygiene, and evaluate the dental implant both clinically and radiographically at frequent recall visits with your dentist.