Twenty-eight CCXBB blocks were placed in 15 patients that fulfilled the selection criteria (12 women and 3 men) with a mean age of 54.5 (SD 8.34).

The detailed clinical and radiographical outcomes have been reported previously [21]. In brief, one patient experienced pain and soft tissue dehiscence leading to removal of the graft material 3 days after the regenerative procedure. Another patient refused to proceed to implant placement after suffering an early dehiscence also leading to a complete removal of the graft. From the remaining 13 patients completing the study, the alveolar ridge width augmented from a mean 2.78 mm (SD 0.55) at baseline to 6.90 mm (SD 1.22) at re-entry, resulting in a statistical significant mean alveolar crest width gain of 4.12 mm (SD 1.32) Sixteen weeks after implant placement a second stage procedure and a soft tissue augmentation was performed (Fig. 7).

Although soft tissue dehiscence, with different degrees of graft exposure, occurred at different time points in 5 out of 15 patients (33.3%) (Fig. 8), 24 implants were placed in 13 patients. Table 1 depicts the data on survival rates at the time of loading. Three implants were lost in three patients at the time of abutment connection, and one patient presenting very narrow ridge at baseline (<2 mm) lost all the implants. Nevertheless, all implants could be replaced without additional grafting procedure.

Histological biopsies from 13 patients were harvested and processed for histological analysis. The histomorphology of the healed CCXBB bone grafts evidenced in most of the samples newly formed mineralized vital woven bone, as well as residual graft material, bone marrow, and non-mineralized connective tissue (Fig. 5). Residual CCXBB appeared to be integrated with the new bone, which had grown within the graft trabeculae. CCXBB and DBBM were identified only by the presence of empty lacunae and cement lines separating the graft from the parent bone (Fig. 5c). In four of the specimens analyzed, minimal or no signs of new bone formation were appreciated, showing an inflammatory infiltrate with neutrophils and macrophages associated with tissue destruction (Fig. 4b).