.

Figure 1.. Radiographs of a defect treated with polymer-coated gelatin sponge impregnated with recombinant bone morphogenetic protein 2 (0.4 mg/cm³) (anteroposterior view). (A-H) Radiographs were taken at 0 (A), 4 (B), 8 (C), 16 (D and E; before and after plate removal, respectively), 32 (F), 52 (G) and 104 (H) weeks postoperatively. Arrowheads in B and C indicate the hypertrophic bone beyond the metal plate. Reproduced from Kokubo et al.³⁹ with permission from Elsevier.