Aims

Recent studies revealed that implants can migrate in bone when subjected to continuous loading. Since this process is suspected to be accompanied by bone remodeling which requires blood vessel formation, the present work aimed at assessing the micro-angiogenic patterns around migrating implants.

Materials and methods

In 16 rats, two customized implants were placed in a single tail vertebra and connected with contraction springs (forces: 0 N, 0.5 N, 1.0 N, 1.5 N). After two or eight weeks of loading, the animals were scanned by micro-CT before and after vasculature perfusion with a silicone rubber. Vessels were segmented by subtraction of the two micro-CT scans. Vessel thickness (V.Th), vessel volume per total volume (VV/TV), and vascular spacing (V.Sp) were assessed in a peri-implant volume of interest (VOI) around each implant.

Results

At two weeks of loading, force magnitude was significantly associated with VV/TV and V.Th values (χ2=10.942, P<0.001 and χ2=6.028, P=0.010, respectively). No significant differences were observed after eight weeks of loading.

Conclusions

Within the limitations of an animal study, peri-implant vessel thickness and density were associated with force magnitude in the early loading phase, whereas effects diminished after eight weeks of loading.