COLLAGEN GEL AND MEMBRANE IN GUIDED TISSUE REGENERATION IN PERIODONTAL FENESTRATION DEFECTS IN DOGS

The effect of a collagen gel matrix as a submembranous space-maintaini ng material was evaluated in guided tissue regeneration procedures. In 4 dogs, contralateral surgical circular fenestration defects, 5 mm in diamter, were produced at the midbuccal aspect of the alveolar bone i n 8 maxillary canines. Removal of bone, PDL and cementum was complete. Experimental sites were filled with collagen gel and covered with col lagen membranes; control sites were covered with collagen membranes an d the underlying space was spontaneously filled with blood. Mucogingiv al flaps were repositioned. Histological and histomorphometric observa tions, 6 weeks post-surgery, indicated that defects covered by collage n membranes presented the most impressive regeneration with almost com plete coverage of the denuded root by new cementum (98.4%) and new bon e (63.2%). In the experimental defects, 83.5% coverage of new cementum with only 21.9% new bone regeneration was observed. These results sug gest that collagen gel, interfered with healing by PDL and bone-derive d cells in the submembranous space.