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 mm(2) versus 7.1 +/- 1.1 mm(2)) and MT (2.7 +/- 0.9 mm(2) versus 1.7 +/- 0.8 mm(2)) values compared to the control sites (P <0.05; paired t test). CONCLUSION: BCP + rhPDGF-BB might have the potential to support the initial stages of guided bone regeneration at chronic-type lateral ridge defects.