Optimal microvessel density from composite graft of autogenous maxillary cortical bone and anorganic bovine bone in sinus augmentation: influence of clinical variables

Objectives The objectives of this study were to assess the microvessel density (MVD) of intra-sinus grafts after 6 months of wound healing and to study the relationship between revascularization processes and patient clinical variables and habits. Material and methods We performed 45 maxillary sinus augmentations with different implant placements in 25 consecutive patients, obtaining bone cores of the grafted area for histological, histomorphometric and immunohistochemical study. Biopsies were also taken from pristine bone in the posterior maxilla (control). Results All implants survived at 24 months. Biopsies of sinus augmentation areas showed significantly greater remodeling activity vs. pristine bone, with significantly more osteoid lines. The morphometry study revealed 34.88 +/- 15.2% vital bone, 32.02 +/- 15.1% non-mineralized tissue and 33.08 +/- 25.4% remnant anorganic bovine bone particles. The number of CD34-positive vessels was 86.28 +/- 55.52/mm2 in graft tissue vs. 31.52 +/- 13.69/mm2 in native tissue (P=0.002, Mann-Whitney U=46). The larger amount of non-mineralized tissue in grafts was directly correlated with a higher MVD (r=0.482, P=0.0001, Pearson's test). MVD was affected by the presence of periodontitis or tobacco and alcohol consumption. Conclusion The angiogenesis and revascularization obtained by this type of graft achieve adequate tissue remodeling for osseointegration and are influenced by periodontal disease and tobacco or alcohol consumption.