[Effect of glass ceramics on bone regeneration in calvarial defects. Experimental study]. / Einfluss von Glaskeramiken auf die Knochenneubildung in Calvariadefekten. Experimentelle Untersuchung.

ABSTRACT

INTRODUCTION: The purpose of this study was to investigate the influence of different compositions of resorbable porous glass ceramics on their performance in calvarial defects. MATERIAL AND METHODS: Full-thickness defects (8.1 mm diameter) were made in the calvaria of 75 adult Sprague-Dawley rats. Pellets of porous glass ceramics were inserted press-fit into 60 defects. Four different materials were implanted into each of 15 animals (1) glass ceramic with a high relation of calcium to phosphate containing silicate; (2) glass ceramic with a high relation of calcium to phosphate without silicate; (3) glass ceramic with a low relation of calcium to phosphate without silicate; and (4) glass ceramic with a low relation of calcium to phosphate containing silicate. Five implants of each group were evaluated by fluorescence microscopy and light microscopy after 6, 13, and 26 weeks. RESULTS: Those glass ceramics with a high relation of calcium to phosphate showed formation of new bone entering the defect from the margins as soon as 6 weeks postoperatively. After 26 weeks, the formation of new bone reached the center of the defect. In the other glass ceramics, the formation of unmineralized osteoid was visible entering the defect from the margins. No mineralization was seen 26 weeks postoperatively. There was no significant difference between glass ceramics containing silicate and those free of silicate. CONCLUSIONS: Bioresorbable glass ceramics may be of benefit in the treatment of osseous defects without functional loading.