Following trauma, chronic periapical process, or tooth extraction, a large loss of bone volume is noticed during the healing process. To facilitate the placement of dental implants, various surgical procedures are used for an optimal alveolar ridge profile, while maintaining adequate bone dimensions. The main aim of this study was to determine the healing ability (histologically and immunohistologically) of alveolar bone defects during augmentation with two different biomaterials: injectable biphasic calcium phosphate (BCP) and anorganic bovine bone (ABB). Thirty-eight subjects were randomly divided into two groups. The first group received the tested bone substitute biomaterial (BSB), i.e., BCP (maxresorb inject®), and the second group received an alternative to the gold standard, i.e., ABB (Bio-Oss®). The histopathological, histomorphometric, and immunohistochemical analyses gave comparable results for these bone substitute materials in terms of newly formed bone: (BCP: 39.91 ± 8.49%, ABB: 41.73 ± 13.99%), residual biomaterial (BCP: 28.61 ± 11.38%, ABB: 31.72 ± 15.52%), and soft tissue (BCP: 31.49 ± 11.09%, ABB: 26.54 ± 7.25%), with no significant difference found between the groups (p < 0.05, t-test), proving that BCP is equally suitable and successful for alveolar bone regeneration.

Xenogeneic biomaterials Cerbone® and OsteoBiol® are widely used in oral implantology. In dental practice, xenogeneic biomaterial is usually combined with autologous bone to provide bone volume stability needed for long-term dental implants. Magnesium alloy implants dissolve and form mineral corrosion layer that is directly in contact with bone tissue, allowing deposition of the newly formed bone. CSBD heals by intramembranous ossification and therefore is a convenient model for analyses of ostoconductive and osteoinductive properties of different type of biomaterials. Magnesium alloy-enriched biomaterials have not yet been applied in oral implantology. Therefore, the aim of the current study was to investigate biological properties of potentially new bovine xenogeneic biomaterial enriched with magnesium alloy in a 5 mm CSBD model. Osteoconductive properties of Cerabone®, Cerabone® + Al. bone, and OsteoBiol® were also analyzed. Dynamics of bone healing was followed up on the days 3, 7, 15, 21, and 30. Calvary bone samples were analyzed by micro-CT, and values of the bone morphometric parameters were assessed. Bone samples were further processed for histological and immunohistochemical analyses. Histological observation revealed CSBD closure at day 30 of the given xenogeneic biomaterial groups, with the exception of the control group. TNF-α showed high intensity of expression at the sites of MSC clusters that underwent ossification. Osx was expressed in pre-osteoblasts, which were differentiated into mature osteoblasts and osteocytes. Results of the micro-CT analyses showed linear increase in bone volume of all xenogeneic biomaterial groups and also in the control. The highest average values of bone volume were found for the Cerabone® + Mg group. In addition, less residual biomaterial was estimated in the Cerabone® + Mg group than in the Cerabone® group, indicating its better biodegradation during CSBD healing. Overall, the magnesium alloy xenogeneic biomaterial demonstrated key properties of osteoinduction and biodegradidibility during CSBD healing, which is the reason why it should be recommended for application in clinical practice of oral implantology.

This prospective, randomized, controlled clinical trial reports clinical, radiographic, histologic and immunohistochemical results of autologous dentin graft (ADG) and its comparison with a mixture of bovine xenograft with autologous bone (BX+AB). After tooth extraction in the esthetic zone of maxilla, the alveolar ridge of 20 patients in the test group was augmented with ADG, while 17 patients in the control group received the combination of BX+AB. Cone beam computed tomography (CBCT) was performed before tooth extraction and after 4 months when a total of 22 bone biopsies were harvested and subjected to histological and immunohistochemical analysis. Radiological analysis showed comparable results of bone dimension loss in both groups. Quantitative histologic analysis showed comparable results with no statistically significant differences between the groups. Immunohistochemical staining with TNF-α and BMP-4 antibodies revealed immunopositivity in both groups. A statistically significant difference between the groups was found in the intensity of TNF-α in the area of newly formed bone (p = 0.0003) and around remaining biomaterial particles (p = 0.0027), and in the intensity of BMP-4 in the area around biomaterial particles (p = 0.0001). Overall, ADG showed biocompatibility and achieved successful bone regeneration in the esthetic zone of the maxilla similar to BX+AB.

Autologous dentin is frequently used in guided bone regeneration due to its osteoinductive properties, which come from its similarity to native bone. On the other hand, the xenogeneic bone biomaterial Cerabone® serves as a biocompatible, but hardly resorbed biomaterial. During bone healing, an inflammatory, vascular, and osteogenic response occurs in which cytokines such as tumor necrosis factor-alpha (TNF-α), vascular endothelial growth factor (VEGF), and osteopontin (OPN) are released locally and systemically. The aim was to follow up the dynamics (on days 3, 7, 15, 21, and 30) of critical-sized bone defect (CSBD) healing after the implantation of bovine devitalized dentin, rat dentin, and xenogeneic bone biomaterial. For this purpose, histological and histomorphometric methods were employed. Additionally, serum concentrations of TNF-α, VEGF, and OPN were monitored in parallel to better understand the biomaterial-dependent systemic response in rats. At the last time interval, the results showed that the bone defect was bridged over in all three groups of biomaterials. The rat dentin group had the highest percentage of bone volume (BV/TV) and the least percentage of residual biomaterial (RB), which makes it the most optimal biomaterial for bone regeneration. Serum concentrations of the TNF-α, VEGF, and OPN refer to systemic response, which could be linked to intense bone remodeling between days 15 and 21 of the bone healing.

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