Failure of a dental implant is often related to the failure of the implant to osseointegrate correctly with the bone, or vice-versa. A dental implant is considered to be a failure if it is lost, mobile or shows peri-implant (around the implant) bone loss of greater than 1.0 mm in the first year and greater than 0.2 mm a year after. In a study here (http://www.ncbi.nlm.nih.gov/pubmed/21055752), 264 implants were examined and 131 of those had peri-implanitis associated bone loss.
Use tapered implants to ensure your dental implants don't suffer from bone loss.
