Comparison of Injectable Biphasic Calcium Phosphate and a Bovine Xenograft in Socket Preservation: Qualitative and Quantitative Histologic Study in Humans

This study is the first histologic evaluation of an injectable biphasic calcium phosphate (IBCP) in humans six months after socket preservation according to the principles of guided bone regeneration. After tooth extraction, the alveolar ridge of 21 patients was augmented with IBCP (maxresorb(R) inject) in the test group, while 20 patients in the control group received a bovine xenograft (BX) (cerabone(R)). Six months after augmentation, a reentry procedure was performed to collect biopsies of regenerated bone for qualitative and quantitative histologic analysis. A total of 20 biopsies were taken for analysis. Qualitative histologic analysis showed complete integration of the biomaterial and no inflammatory tissue reaction, indicating the biocompatibility of the bone grafts and the surrounding tissue in both groups. Histomorphometric analysis showed comparable results in terms of newly formed bone (IBCP: 26.47 +/- 14.71%, BX: 30.47 +/- 16.39%) and residual biomaterial (IBCP: 13.1 +/- 14.07%, BX: 17.89 +/- 11.81%), with no significant difference found across groups (p > 0.05, Mann-Whitney U test). Statistical significance between groups was found in the result of soft tissue percentage (IBCP: 60.43 +/- 12.73%, BX: 51.64 +/- 14.63%, p = 0.046, Mann-Whitney U test). To conclude, IBCP and BX showed good osteoconductivity and biocompatibility with comparable new bone formation six months after alveolar ridge preservation.