Influence of Recombinant Human Platelet‐Derived Growth Factor on Lateral Ridge Augmentation Using Biphasic Calcium Phosphate and Guided Bone Regeneration: A Histomorphometric Study in Dogs

Background: The present study investigated the effects of recombinant human platelet‐derived growth factor‐BB (rhPDGF‐BB) on initial bone formation following lateral ridge augmentation using biphasic calcium phosphate (BCP) in combination with a native collagen membrane (CM) in dogs. Methods: Eight chronic‐type mandibular lateral ridge defects in four beagle dogs (two defects each) were randomly allocated in a split‐mouth design to BCP + rhPDGF‐BB + CM (test) or BCP + CM (control). After 3 weeks, dissected blocks were prepared for immunohistochemical (angiogenesis‐transglutaminase II [TG]) and histomorphometric analysis (e.g., augmented area [AA] and mineralized tissue [MT]). The biologic activity of rhPDGF‐BB soak‐loaded BCP was verified by means of alkaline phosphatase and lactate dehydrogenase assays in a SaOs‐2‐osteoblast‐like cell culture. Results: Both groups exhibited a comparable pattern of blood vessel and bone formation that mainly originated from the adjacent alveolar bone. However, test sites revealed a pronounced TG antigen reactivity, which was associated with statistically significant higher mean AA (8.5 ± 0.9 mm2 versus 7.1 ± 1.1 mm2) and MT (2.7 ± 0.9 mm2 versus 1.7 ± 0.8 mm2) values compared to the control sites (P