Novel grafting materials for sinus floor elevation in the sheep model

Abstract

Introduction:

Sinus floor elevation (SFE) may be required for implant placement in the severely resorbed posterior maxilla. Although often successful, autologous bone grafting requires a donor site and may lose substantial volume while remodelling. Bone replacement grafting (BRG) materials were developed to overcome these limitations. This study investigated three novel grafting materials: 1) equine collagen cone (CN), 2) equine collagen cone filled with biphasic calcium phosphate particles (CO), 3) deproteinized bovine bone particles coated with polylactic acid and poly ε -caprolactone copolymer (SB). These were compared with the most commonly-used bovine bone BRG, Geistlich Bio-Oss® (BO).

Methods:

The extra-oral access sinus grafting model from Haas et al. (1998) was used in 11 cross-bred female sheep. Two experimental sites on each side of the animal were prepared. CN, CO, SB, BO were each placed through separate 10 mm access window in the antral wall, under the elevated Schneiderian membrane. BO sites were covered with a porcine collagen membrane (Geistlich Bio-Gide®), while for CO, SB, BO sites the equine collagen membrane (RESORBA PARASORB®) from the manufacturer of these experimental materials was used. The animals were euthanised after 16 weeks. New bone, residual graft particles and connective tissue areas were measured on un-demineralised resin-embedded sections.

Results:

One sheep did not survive the surgery. All sites in remaining ten sheep healed uneventfully. The CN and SB grafting materials resorbed completely and failed to form new bone. BO and CO particles were bridged by the new bone, the new bone fraction was 10% (±9%) for BO and 4% (±5%) for CO. The differences were not statistically significant.

Conclusions:

CN and SB cannot be recommended for sinus grafting, based on this model. BO and CO demonstrated comparable histologic and histomorphometric outcomes.