Initial pattern of angiogenesis and bone formation following lateral ridge augmentation using rhPDGF and guided bone regeneration: an immunohistochemical study in dogs

Abstract

To evaluate (i) the effects of rhPDGF-BB on localized ridge augmentation using a natural bone mineral (NBM), and (ii) the influence of a collagen membrane (CM) on factor activity. Chronic-type alveolar ridge defects (n = 4 dogs) were randomly allocated in a split-mouth design as follows: upper jaw: NBM + rhPDGF-BB + CM (test) vs. NBM + rhPDGF-BB (control), and lower jaw: NBM + rhPDGF-BB + CM (test) vs. NBM + CM (control). After 3 weeks, dissected blocks were prepared for immunohistochemical (angiogenesis - TG) and histomorphometrical analysis [e.g. augmented area (AA), mineralized - (MT), non-mineralized tissue (NMT) (mm(2))]. Lower jaw: TG and mineralization of AA mainly originated from the defect borders. Test sites revealed a pronounced TG antigen reactivity and higher AA and MT values (mean and median). Upper jaw: control sites revealed a dislocation of AA in caudal direction, but also an improved vascularization in the peripheral wound area. While MT values (median) appeared to be comparable in both groups, AA, NMT, and NBM values (mean and median) tended to be higher at test sites. It was concluded that (i) rhPDGF-BB soak-loaded on NBM might have the potential to support bone formation at chronic-type lateral ridge defects, and (ii) the application of CM did not seem to interfere with the factor activity, but ensured a stabilization of the graft particles.