Histomorphometric analysis and VEGF expression after alveolar ridge preservation with beta‐TCP collagen in the maxillary esthetic zone

Background Beta-tricalcium phosphate in combination with a type I collagen (beta-TCP Coll) has been shown to be capable for supporting new bone formation and soft tissue healing at the area of socket opening. Since preservation of alveolar ridge holds great promise for maintaining the original dimension of alveolar bone, the treatment of maxillary esthetic zone may be introduced as challenging from both biological and clinical standpoints. Aim/Hypothesis The aim was to present comparative results of histologic, histomorphometric and immunohistochemical outcomes of single-implant restoration during healing period after 2 and 4 months of alveolar ridge preservation in patients treated with beta-TCP Coll and collagen sponge of bovine origin Material and Methods The study was conducted in 20 healthy patients divided into two groups- A) 2, and B) 4 months of healing. All treated postextracted sockets with four intact walls in the maxillary esthetic zone were preserved with beta-TCP Col (RTR Cone® Septodont, France), covered with ColSp (Hemocollagene® Septodont, France), immediately after tooth extraction, for single-implant restoration (Astra tech® 4.0 S 11 mm). Bone biopsies from the grafted sites were collected 2 and 4 months later. Bone samples were analyzed using histomorphometry (percentage of new bone formation, marrow bone, residual graft, fibrous tissue and blood vessels) and immunohistochemistry (Elisa VEGF expression and protein staining). Results The areas of mineralized new bone formation with trabecular connectivity were significantly increased in group B (38.46%) than in group A (24.06%). The connective tissue, mostly occupied centrally with incorporated residues of material inside, were significantly more detected in group A (39.44%) in comparison with group B (30.03%). There was new bone tissue formation with no significant differences between the two groups in the areas occupied by bone marrow (A-4.33%+ B-11.89%), bone graft (A-31.93%+ B-19.43%), or new blood vessels (A-0.24%+ B-0.19%). Significantly more VEGF expression was recorded after 2 than 4 months of healing with cellular osteoblast and endothelial cell staining. Conclusion and Clinical Implications Alveolar ridge preservation with beta-TCP Col + ColSp may allow new well vascularized bone formation to provide subsequent implant placement after an observation period of 4 months in the maxillary esthetic zone.