Bone tissue modelling and remodelling following guided bone regeneration in combination with biphasic calcium phosphate materials presenting different microporosity

ObjectivesThe aim of this study was to investigate bone regeneration following application of a novel biphasic calcium phosphate (BCP I) composed of microstructured granules of 90% -tricalcium phosphate (-TCP)/10% hydroxyapatite (HA) compared to BCP non-microstructured biphasic calcium phosphate with a composite of 60% hydroxyapatite/40% -TCP (BCP II) and a deproteinized bovine bone mineral (DBBM) at surgically created defects in the mandible of minipigs in a combined approach with guided bone regeneration (GBR). Material and methodsSixteen minipigs were used for the study. Lower premolars P2, P3, P4 and first molar M1 were extracted. Following 3months of healing, two defects with a width and depth of 7mm were created bilaterally in the mandible. The different grafting materials were randomly placed in the created defects and covered by means of a collagen membrane. After 3 and 8weeks, biopsies were sampled. All specimens were evaluated with descriptive histology and histomorphometric evaluations complemented by micro-CT scan analysis. ResultsAll three biomaterials presented with higher bone volume at 8weeks compared to 3weeks (P<0.0442). BCP I and DBBM demonstrated a significant higher amount of bone formation compared to BCP II at 8weeks (P<0.0328). BCP I also demonstrated a significant higher percentage of remaining graft volume compared to the other test groups both at 3 and 8weeks (P<0.0001 to P<0.0003). Congruently, defects containing BCP I showed a significant higher amount of mineralized tissue compared to the other groups. ConclusionsAll the three test materials performed well with regard to bone formation at 8weeks. BCP I showed significant higher amounts of newly formed bone despite a higher remaining graft volume compared to the other groups. With regard to the regenerative outcome, all the three materials can be recommended for clinical use.