Deproteinized Bovine Bone Mineral or Autologous Bone at Dehiscence Type Defects at Implants Installed Immediately into Extraction Sockets: An Experimental Study in Dogs

Purpose: The aim of this study was to evaluate bone regeneration at surgically created dehiscence buccal defects at implants placed immediately into extraction sockets (IPIES) of small dimensions filled with autogenous bone or deproteinized bovine bone mineral (DBBM) associated with a collagen membrane. Materials and Methods: Eight Labrador dogs were used and implants were placed immediately into the extraction sockets of the second premolar. The buccal wall was subsequently removed to create a standardized defect, 4 mm wide coronally, 2 mm wide apically, and 6 mm high. Autogenous bone particles (AB) or DBBM granules were used to fill the defects. All surgical sites were subsequently covered by a resorbable collagen membrane and a non-submerged healing was allowed. After 4 months, the animals were euthanized and bone blocks harvested and processed for histomorphometric analysis. Results: The bony crest at the buccal aspect (C) was located 2.3 +/- 0.8 mm and 1.7 +/- 0.7 mm apically to the implant shoulder (IS) at the AB and DBBM sites, respectively. The coronal levels of osseointegration at the buccal aspect (B) were located 2.7 +/- 0.7 mm and 2.2 +/- 1.0 mm apically to IS at the AB and DBBM sites, respectively. At the AB sites, the peri-implant mucosa was located 4.3 +/- 0.9 mm, 4.7 +/- 0.9 mm, and 2.0 +/- 1.6 mm coronally to C, B, and IS, respectively. The corresponding values at the DBBM sites were 4.3 +/- 0.6 mm, 4.8 +/- 0.6 mm, and 2.5 +/- 0.8 mm, respectively. No statistically significant differences were found. Conclusions: The treatment of surgically created buccal defects at IPIES sites using Bio-Oss (R) (Geistlich Biomaterials, Wolhusen, LU, Switzerland) or autogenous bone, concomitantly with a collagen membrane, engenders bone regeneration to a similar extent after 4 months of healing.