Augmentation of exposed implant threads with autogenous bone chips: prospective clinical study.

BACKGROUND

Autogenous bone chips can be harvested during drilling of implant sites and may be used as a graft material for bone augmentation and coverage of exposed implant threads.

PURPOSE: The aim of this prospective study was to evaluate the possibility of augmenting exposed implant threads with autogenous bone chips.

MATERIALS AND

METHODS

Twenty-one consecutive patients treated with screw-shaped oral implants with exposed threads due to buccal fenestration or marginal defects were augmented with autogenous bone harvested with a bone trap during drilling of the implant site. Both marginal (9 sites) and fenestration defects (12 sites), with 4 to 14 exposed implant threads, were registered clinically and with photography. The number of exposed implant threads was measured before and at second-stage surgery 6 months after augmentation.

RESULTS

Complete bone coverage of the exposed implant threads was seen in 12 of the 21 implant sites. Six sites showed one to two remaining exposed threads, two showed about 40% coverage, and one showed flattening of the defect but with eight of nine exposed threads at 6 months follow-up. The mean bone gain was 81% in patients with a marginal defect and 82% in patients with a fenestration defect.

CONCLUSION

The results from this clinical study show that it is possible to gain bone over exposed implant threads by augmentation with autogenous bone chips.