Figures 4–7. Figure 4. Patient 4, control graft: Large Bio-Oss (B) particles were bridged by new bone (NB) formation on their surfaces (original magnification ×4). Figure 5. Patient 5, test graft: Resorbing Puros (P) particles are visible as dark areas within significant new bone (NB) formation (red areas). Puros leaves new bone behind as it resorbs (original magnification ×4). Figure 6. Patient 6, test graft: Puros (P) graft particles were incorporated in new bone (NB) and underwent resorption as the new bone formed (original magnification ×4, polarized). Enlargement (insert) shows the pattern of allograft incorporation more clearly (original magnification ×10). Figure 7. Patient 7, test graft: Puros (P) particles are difficult to distinguish from new bone (NB) (original magnification ×10)