Healing of BoneCeramic™ at buccal dehiscence defects at implants installed immediately into extraction sockets. An experimental study in dogs

Abstract

To assess the healing outcomes at buccal dehiscence defects after 4months following implant placement immediately into extraction sockets (IPIES) and filled with a mixture of synthetic hydroxyl apatite (HA) 60% and β-tri-calcium phosphate (β-TCP) 40% in comparison with leaving a blood clot. Eight Labrador dogs were used, and an implant was placed immediately following tooth extraction into the distal alveolus of the third premolars, bilaterally. Standardized buccal defects, 8mm in depth and 4mm in width at the coronal and 2mm in width at the apical outlines were created. A mixture of synthetic HA 60% and β-TCP 40% was used to fill the defects at the test sites, while the control sites were left unfilled. Collagen membranes were used to cover the defects at both sides, and a non-submerged healing was allowed. After 4months of healing, biopsies were obtained and processed for morphometric analysis. A vertical gain in the extent of the bony crest and of osseointegration levels of 4.2±2.4 and 3.3±2.1mm at the test sites and of 5.0±0.8 and 4.6±1.0mm at the control sites, respectively, were observed. BIC% within the buccal defects reached similar levels (37-42%) both at test and control sites. None of the means of the variables differed significantly between the two groups. New bone formation within the defects was higher, and the percentage of the connective tissue was lower at the control (65.7±11.7% and 2.5±3.3%, respectively) compared to the test sites (16.8±11.3% and 48.9±29.5%, respectively). These differences were statistically significant. The use of a mixture of synthetic HA 60% and β-TCP 40% to fill surgically created buccal dehiscence defects at IPIES sites covered with a collagen membrane did not improve osseointegration in the defect area.