The immune-histochemical results reported expression of osteopontin mainly at the border between mineralized vital bone (MVB) with CCXBB, what coincides with findings from previous reports [38,39,40]. Alkaline phosphatase (ALP) is considered as an early osteoblast differentiation marker [41]. ALP-positive cells were detectable, in all specimens on the periphery of MVB, associated to areas of new bone formation. These observations were also reported on a clinical study on guided bone regeneration (GBR) [41], as well as through the evaluation of the healing of particulate xenogeneic bone grafts (DBBM) [28]. Experimental research using immune-histochemical analysis for comparing early bone remodelling between autografts and allografts has reported comparable behavior for osteoprotegerin (OPG), alkaline phosphatase (ALP), collagen 1 (COLI), osteopontin (OPN), and osteocalcin (OSC), although an increased activity of tartrate-resistant acid phosphatase (TRAP) was seen in allogenic bone grafts [42]. In this investigation TRAP, which is a specific enzyme present in large quantities at the osteoclasts edge expressing bone resorption, was present in high proportions in all the analysed samples. On the other hand, OSC (bone matrix protein), predominantly synthesized by osteoblasts, has a fundamental role in bone formation (mineralization) and resorption [43]. Experimental studies have demonstrated the role of OSC during the early healing phases of osseointegration of dental implants [44]. In the present investigation, a statistical significant correlation between higher levels of OSC and implant loss was found. This association could be explained by a greater activity of bone modelling in these situations of deficient mineralization [45].

This prospective single-arm study has clear limitations to evaluate the efficacy of this bone regenerative intervention, since there is not a control group [46]. However, this investigation has shown excellent clinical performance and histological outcomes when CCXBB were used for lateral bone augmentation and when their integration occurred without soft tissue dehiscence.