The purpose of this study was to investigate the effectiveness of using guided tissue regeneration (GTR) with an absorbable membrane for the preparation of immediate dental implants.
Osseous defects were create in the edentulous region of rabbit mandibles. After implanting cylindrical hydroxylapatite (HA). half of the defects were covered with VicrylR woven mesh and the other half were not.
The animals were sacrificed 1, 2, 4 and 8 weeks postoperatively.
Non-decalcified specimens, 15 pm in thickness, were prepared, stained with toluidine blue and examined histologically.
The following results were obtained:
1. In the non-covered defects, connective tissue existed between the new bone and the upper half of the HA implant by 8 weeks.
2. In the mesh-covered defects, direct bonding between newly formed bone and the HA surface under the mesh, without connective tissue in the upper half, was observed 4 weeks postoperatively.
3. Mononuclear and multinuclear cells were observed around the mesh at 1 week. The structure of the mesh became unclear at 4 weeks and the mesh was completely absorbed at 8 weeks. A tendency to cause tissue reactions was not observed. These results indicate that guided tissue regeneration with an absorbable membrane is useful for the preparation of immediate dental implants.