Hydroxyapatite Block Produced by Sponge Replica Method: Mechanical, Clinical and Histologic Observations

Purpose: The grafting procedure for the anthropic ridges of jaws represents a surgical technique for increasing the bone volume to permit the placement of dental implants for oral rehabilitations. The aim of this study was to evaluate a hydroxyapatite (HA) porous scaffold produced via a sponge replica method for the treatment of maxillary bone defects in a human model. Methods: A total of thirteen patients were treated for sinus lifting in the posterior maxilla for a total of 16 defects treated with cylindrical HA Block. The experimental sites were evaluated by a 3D Cone Beam Computer Tomography scan (CBCT), and the histological analysis was performed after 3 months of healing. Results: After the 3 months healing period, the histological outcome of the investigation showed a high level of biological osteoconduction of the HA. Microscopical evidence of new bone formation was also observed in the central portion of the graft block. The samples were composed of different tissues: 39 +/- 1% new bone, 42 +/- 3% marrow space, 17 +/- 3% residual HA Block and 4.02 +/- 2% osteoid tissue were present. The new bone formation in the block was 8 +/- 3%. Conclusions: The study findings support that HA porous scaffolds produced by sponge replica were effective for the treatment of maxillary bone defects in humans.