Evaluation of peri-implant bone resorption around Straumann Bone Level implants placed in areas reconstructed with autogenous vertical onlay bone grafts.

AIM OF THE STUDY

To evaluate the survival and success rate of Straumann Bone Level implants placed in vertically atrophied edentulous jaws previously reconstructed with autogenous onlay bone grafts taken from the calvarium or the mandibular ramus.

MATERIALS AND METHODS

From 2007 to 2009, 18 patients presenting with vertical deficits of the edentulous ridges were treated with autogenous cortical bone grafts harvested from the mandibular ramus or the calvarium. Four to seven months afterward, 60 Straumann Bone Level implants were placed in the reconstructed areas. After a further waiting period of 2-3 months, patients were rehabilitated with implant-supported fixed prostheses. Follow-up ranged from 12 to 36 months (mean: 19 months) after the start of prosthetic loading. Graft resorption before implant placement, as well as survival and success rates of implants, were recorded.

RESULTS

The mean bone resorption prior to implant placement was 0.18 mm for calvarial grafts and 0.42 mm for ramus grafts. Survival rate was 100% either for implants placed in calvarial grafts or implants placed in ramus grafts, while success rate was 90.3% for implants placed in calvarial grafts, and 93.1% for implants placed in ramus grafts.

CONCLUSION

Results from this study seem to demonstrate that implants with a platform-switching design may predictably integrate in edentulous areas reconstructed with autogenous bone grafts, with survival rates consistent with those reported in recent literature reviews on the same topic, and also with implants placed in native bone. Conversely, this study was not able to demonstrate that implants with platform-switching design may reduce bone resorption around implants placed in reconstructed areas.