Morphological evidences of Bio‐Oss® colonization by CD44‐positive cells

Abstract

Our objectives were to examine vascular and cellular colonization in anorganic bovine bone (ABB) after 6months of healing in human maxillary sinus augmentation grafts. Fifty unilateral maxillary sinus augmentation procedures were performed on 50 consecutive patients. Bone cores were obtained through the implant receptor sites 6months later and evaluated with morphological image analysis and immunohistochemical techniques. Image analysis revealed a mean of 35.44±16% vital bone, 31.66±15% non-mineralized tissue, and 32.72±25% remnant ABB particles. In our patients, neovascularization in 46.3% of cases was demonstrated within ABB particles 6months after sinus floor augmentation surgery. Neovascularization of ABB particles was inversely related to age, directly to osteoclast number per mm², and not influenced by habits or disease. CD44-positive cells colonization was found in 74% of cases. An important correlation was found regarding CD44 expression and number of vessel in ABB particles (r=0.624 P<0.001, Pearson). Osteopontin expression was detected on the interstitial boundary of bone with ABB particles and within the osteocyte lacunae and bone canaliculi and was relationship with presence of CD44-positive cells inside ABB particles (r=0.388, P=0.046, Pearson). In conclusion, images compatible with osteone colonized by osteocytes CD44 positive and neovascularization in ABB particles were observed after 6months of graft maturation. These biologic events have not previously been morphologically and immunohistochemically documented.