Bone Density: Its Influence on Implant Stability After Uncovering

Abstract

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.

Bone density and primary stability in implant therapy

“…The investigators found mean PTVs at second-stage surgery of À 3.82 AE 3.04 for type 1, À 3.7 AE 3.06 for type 2, À 3.3 AE 3.2 for type 3 and À 1.29 AE 3.57 for type 4 quality bone. Another group correlated the same techniques and their results show a different change of PTVs over time in densities 1 and 2 compared with 3 and 4, which could indicate a better bone-to-implant contact over time in better bone densities (Morris et al 2003). A similar finding was published in Truhlar et al (2000); these authors added that hydroxyapathite-coated implants became less stable over time in contrast with noncoated implants, which showed an improvement in stability over time.…”

Clinical and radiographic evaluation of NobelActiveTM dental implants

“…These have been described as being useful methods to assess primary implant stability (Göransson & Wennerberg 2005). They were also reported to yield valuable information on bone healing during osseointegration (Huang et al 2005) and on changes in the bone-implant interface after uncovering (Morris et al 2003).…”

Overdentures in the Edentulous Mandible Supported by Implants and Retained by a Dolder Bar: A 5‐Year Prospective Study

“…8 Survival rates are documented to range from 97.1% to 100% based on implants and from 88% to 100% based on superstructures after 1 to 10 years of follow-up. 9 Multiple factors contribute to implant survivalincluding bone quantity and quality, primary stability, number/length/diameter/distribution of implants across the arch, 10 implant surface and geometry, [11][12][13] loading protocol, prosthetic design, occlusal concept, and maintenance of oral hygiene. There is unanimous agreement that primary stability is closely related to bone structure, and that higher rates of implant survival are obtained in the mandible than in the maxilla.…”