Experimental study by fluorescence microscopy and microangiography of remodeling and regeneration of bone inside...

Five female Göttingen minipigs received unilateral subperiosteal implantation of a block of porous hydroxyapatite covered by a polylactic membrane. Five months later, biopsies were taken from the blocks, which were left in place for another 3 months. The biopsies showed bone formation in all pores, indicating complete penetration of the blocks after 5 months. Highly vascular tissue with radiographic signs of bone resorption was found in the upper third of the augmentation 3 months later. Fluorescence microscopy showed that all sequential labels were present throughout the whole block. However, a significant decrease in the frequency of the 1-week label was recorded, showing that elevation of the overlying soft tissue may lead to temporary impairment of vascular supply.