Maxillary Sinus-Floor Augmentation by Porcine-Apatite Xenograft: A Prospective Case Series Study.

Abstract

Bone substitutes sometimes are unsuccessful in replacing the autogenous bone graft, combining the advantages and disadvantages to achieve satisfactory results. The aim of this work was to clinically and histologically evaluate the outcome of porcine-apatite xenograft used to elevate the maxillary sinus floor in severe atrophy ridge. A two-stage crestal window sinus lift protocol was conducted in 24 patients with crestal bone ≤2mm. Highly porous porcine carbonate apatite moistened with saline solution was placed in the elevated sinus cavity as the sole grafting material. Bone core biopsies were taken at 6, 9 and 12 months after the sinus augmentation surgery at the time of implant placement. The treatment outcome was assessed using the μCT (micro computed tomogram) and histological analysis. Statistical analysis was performed using the nonparametric Kruskal-Wallis test, followed by the post-hoc Dunn multiple comparison test. At 6 months after implant placement, all implants achieved good primary stability (≥ 30 Ncm of insertion torque) and successfully osseointegrated. The residual graft amount (m±SE) was low (11.91±1.99%) at 6 months, and further decreased (6.11±2.64%) at 12 months after the sinus augmentation surgery. On the contrary, the amount of new bone detected was 18.94±4.08% at 6 months, and significantly (p<0.05) increased (40.16±5.27%) 12 months after sinus augmentation surgery. Histological assessment revealed existing of osteoclasts in resorbing the graft as well as the osteoblasts in forming the new bone. In the severely atrophic maxilla, the porcine-apatite xenograft promotes new bone formation while being slowly absorbed. In conclusion, within the limited sample size, the porcine-apatite xenograft seems to be a good material to be used as the graft material for crestal window sinus augmentation.