Bone density: its influence on implant stability after uncovering.

Primary implant stability and bone density are variables that have long been considered to be essential to achieving predictable osseointegration and long-term clinical survival. Although the dentist can control most factors associated with implant survival, bone density is the one factor that cannot be controlled. Measuring implant stability would assist in determining if an implant has integrated and is ready for the fabrication of the final prosthesis. Changes in implant stability in each type of Bone Quality (BQ-1, -2, -3, and -4), which may occur with time, have not been studied. Such information could help identify well-integrated implants and identify changes associated with impending implant failure. Several studies have used the Periotest instrument to study implant stability. Use of the Periotest implant stability will be studied during each phase of implant treatment for each bone density, and a range for clinically satisfactory integration will be suggested. Implant stability changes over time, and the changes are different for each bone density as the bone surrounding the nonhydroxyapatite implant becomes denser. This is clearly demonstrated in a postmortem histological specimen. The changes in implant stability (Periotest Values [PTVs]) are more apparent in BQ-1 and BQ-2 bone and less apparent in BQ-3 and BQ-4 bone. The Periotest is capable of providing valuable information concerning favorable or unfavorable changes in the bone-implant interface after uncovering. In addition, it can help identify when an implant is ready to be loaded. A new range of PTVs (-5 to -2) is suggested for monitoring the status of implants. Implants with PTVs more positive than -2 would indicate a bone-implant complex that may be marginal.