Maxillary sinus grafting with Bio-Oss® or Straumann® Bone Ceramic:: histomorphometric results from a randomized controlled multicenter clinical trial

Introduction: This investigation was designed to compare the histomorphometric results from sinus floor augmentation with anorganic bovine bone (ABB) and a new biphasic calcium phosphate, Straumann (R) Bone Ceramic (BCP). Materials and methods: Forty-eight maxillary sinuses were treated in 37 patients. Residual bone width was >= 6 mm and height was >= 3 mm and < 8 mm. Lateral sinus augmentation was used, with grafting using either ABB (control group; 23 sinuses) or BCP (test group; 25 sinuses); sites were randomly assigned to the control or test groups. After 180-240 days of healing, implant sites were created and biopsies taken for histological and histomorphometric analyses. The parameters assessed were (1) area fraction of new bone, soft tissue, and graft substitute material in the grafted region; (2) area fraction of bone and soft tissue components in the residual alveolar ridge compartment; and (3) the percentage of surface contact between the graft substitute material and new bone. Results: Measurable biopsies were available from 56% of the test and 81.8% of the control sites. Histology showed close contact between new bone and graft particles for both groups, with no significant differences in the amount of mineralized bone (21.6 +/- 10.0% for BCP vs. 19.8 +/- 7.9% for ABB; P=0.53) in the biopsy treatment compartment of test and control site. The bone-to-graft contact was found to be significantly greater for ABB (48.2 +/- 12.9% vs. 34.0 +/- 14.0% for BCP). Significantly less remaining percentage of graft substitute material was found in the BCP group (26.6 +/- 5.2% vs. 37.7 +/- 8.5% for ABB; P=0.001), with more soft tissue components (46.4 +/- 7.7% vs. 40.4 +/- 7.3% for ABB; P=0.07). However, the amount of soft tissue components for both groups was found not to be greater than in the residual alveolar ridge. Discussion: Both ABB and BCP produced similar amounts of newly formed bone, with similar histologic appearance, indicating that both materials are suitable for sinus augmentation for the placement of dental implants. The potential clinical relevance of more soft tissue components and different resorption characteristics of BCP requires further investigation.