Danai Anna Papavasileiou, Minas Leventis, Georgios Agrogiannis, Demos Kalyvas
In guided bone regeneration, the use of bone substitutes protected by resorbable barrier membranes is suggested for the treatment of bone defects. Sprouting of vessels from surrounding local bone and periosteum into such regenerated areas is an important factor for osteogenesis. However, isolating the grafted area from the overlying periosteum with a barrier membrane may affect the revascularization of the site, thus compromising new bone formation.
The aim of this experimental study was to perform a comparative evaluation of neoangiogenesis in bone defects filled with a bone graft and covered with a resorbable barrier membrane or a collagen fleece.
Eighteen 2.5-3.5 kg weighing New Zealand white rabbits were used. Two circular bicortical bone defects (8 mm in diameter) were created in the calvaria of the animals and subsequently filled with a deproteinized bovine bone mineral ([DBBM]; Bio-Oss®, Geistlich Pharma AG, Wolhusen, Switzerland). One grafted defect was covered with a resorbable collagen membrane (Bio-Guide®, Geistlich Pharma AG) (group A), while the other site was covered by a collagen fleece (Jason® collagen fleece, Botiss Biomaterials GmbH, Zossen, Germany) (group B). The rabbits were divided into three study groups (7, 14, and 28 days), each containing six animals. Specimens were taken, and histological and immunohistological analyses were carried out concerning the number of newly formed vessels.
All specimens showed uneventful bone formation at 28 days. There was a statistically significant difference in the number of blood vessels for the collagen fleece group at all time periods (7, 14, and 28 days).
The results of this study indicate that covering a bone graft with a quickly resorbable biomaterial (collagen fleece) allows for a greater degree of neoangiogenesis compared to a resorbable collagen barrier membrane.
