A morphological and immunohistochemical study on the Guided Bone Regeneration Technique (Gbr) with not resorbable membrane

Introduction:The success of dental implants largely depends on the quality of osseointegration, a complex biological process regulated by several molecular markers. This study aims to evaluate the expression of three key osteogenic biomarkers—Runx2, osteopontin (OPN), and osteocalcin (OCN)—during bone regeneration in critical-size defects treated with biomaterials.Materials and Methods:Critical bone defects were surgically created in rabbit calvariae and filled with various bone substitute materials. Samples were collected at defined healing intervals. Histological, histomorphometric, and immunohistochemical analyses were performed to assess Runx2, OPN, and OCN expression patterns and their association with the newly formed bone tissue.Results:Runx2 was predominantly expressed in early healing phases, indicating active osteoblastic differentiation. OPN showed strong localization in the mineralization fronts, while OCN expression increased in later phases, correlating with bone matrix maturation. Differences in biomarker expression were observed depending on the type of graft material used.Discussion:The temporal and spatial expression patterns of Runx2, OPN, and OCN confirm their pivotal role in different stages of osteogenesis. These findings suggest that monitoring these biomarkers can provide valuable insights into bone substitutes' biological behavior and the osseointegration quality.Conclusion:The differential expression of osteogenic markers in response to bone substitutes offers a valuable tool for evaluating the regenerative potential of biomaterials in implant dentistry. Further research is recommended to validate these results in clinical settings.