BLOOD-FILLED SPACES WITH AND WITHOUT FILLER MATERIALS IN GUIDED BONE REGENERATION - A COMPARATIVE EXPERIMENTAL-STUDY IN THE RABBIT USING BIORESORBABLE MEMBRANES

The aim of the present study was to evaluate the effect of natural dep roteinized bone mineral on the temporal and spatial pattern of bone fo rmation in a guided bone regeneration model system while using a biore sorbable membrane device. A periosteal skin flap was raised uncovering the calvaria of 20 rabbits. A stiff hemispherical dome made of polyla ctic acid was placed onto the roughened calvaria and anchored by screw s. Prior to placement, the dome was either filled with peripheral bloo d (control group, 8 rabbits) or with blood and OsteoGraf/N-300 (test g roup, 12 rabbits). At 1 month, histologic sections revealed bone regen eration in both test and control domes to various degrees. In the test domes, bone height reached 78% (67-83) and bone volume was 11% (6-17) , while in the control domes, bone height was 45% (14-67) and bone vol ume 6% (1-11). At 2 months, bone height was unchanged in the test grou p at 70% (67-83) and bone volume had only slightly increased to 16% (1 1-21). In the controls, height increased to 86% (60-100) and volume to 20% (9-27). Thus, in this model system, natural bone mineral fill con tributed to accelerate initial bone neogenesis, while it did not contr ibute to increasing bone volume or bone height at later observation st ages.