Maxillary sinus floor grafting with β-tricalcium phosphate in humans:: density and microarchitecture of the newly formed bone

Objectives: Graft insertion can effectively enhance the regeneration of debilitated bone. The effects of an alloplastic bone-replacing material, beta-tricalcium phosphate (Cerasorb), and of autogenous bone graft were compared. Materials and methods: In 17 edentulous patients, the maxillary sinus floor was extremely atrophied to such an extent that implant placement was impossible. The Schneiderian membrane was surgically elevated bilaterally by insertion of Cerasorb (experimental side) and autogenous bone graft (control side). After surgery, the recovery was followed clinically and radiologically. After 6 months, 68 bone cylinders were excised from the grafted areas and implants were inserted into their places. The bone samples were embedded into resin, and the osteointegration of the grafts was studied histologically. Trabecular bone volume (TBV) and trabecular bone pattern factor (TBPf) were quantified by histomorphometry. Results: Cerasorb proved to be an effective bone-replacing material with osteoconductivity; it was capable of gradual disintegration, thereby providing space for the regenerating bone. The new bone density was not significantly different on the experimental and control sides (32.4 +/- 10.9% and 34.7 +/- 11.9%, respectively). However, the graft biodegradation was significantly slower on the experimental side than the control side. The TBPf value was lower on the control side than on the experimental side (-0.53 +/- 1.7 and -0.11 +/- 1.4 mm(-1), respectively), but this difference was not significant. Conclusions: Six months after insertion of the grafts, the bone of the augmented sinus floor was strong and suitable for anchorage of dental implants, irrespective of whether autogenous bone or Cerasorb particles had been applied.