Maturation of periodontal tissues following implantation of rhGDF-5/β-TCP in one-wall intra-bony defects in dogs: 24-week histological observations

Objective Although a previous study reported that recombinant human growth/differentiation factor‐5 (rhGDF‐5) coated onto a β‐tricalciumphosphate (β‐TCP) significantly enhanced periodontal regeneration, the long‐term stability/maturation of the regenerated tissues has not been demonstrated. The objective of this study was to evaluate periodontal regeneration/maturation following application of rhGDF‐5/β‐TCP using an established periodontal defect model and a 24‐week healing interval. Material & Methods Unilateral, surgically created, 4 × 4 × 5 mm (length × width × height), one‐wall, critical‐size, intra‐bony periodontal defects at the mandibular second and fourth premolar teeth in five young adult Beagle dogs received rhGDF‐5/β‐TCP. Bilateral sites at the fourth premolar in the other four dogs served as pristine controls receiving mucogingival flap surgery without defect induction. The animals were euthanized at 24 weeks for histological analysis. Unpublished data from the previous 8‐week study were used to compare tissue maturation between 8 and 24 weeks. Results Linear histometric observations of cementum and alveolar regeneration showed no significant differences between the 8‐ and 24‐week observation intervals. However, parameters of periodontal tissue maturation showed significant differences between the observation intervals including increased fraction mineralized tissue and lamellar bone (p