(a) Titanium plasma-sprayed (TPS) surface in graft: General overview shows peri-implant bone with few graft particles and thick bony trabeculae (Toluidine blue, original magnification ×8). (b) TPS surface in graft: Thick peri-implant trabeculae of composite bone (arrows) and new primary osteons (O) (Toluidine blue, original magnification ×50). (c) TPS surface in graft: The new bone contacted only the crests (tips) of the threads (arrows) (Toluidine blue, original magnification ×25). (d) TPS surface in graft: Amorphous interfacial structures in some locations could be ascribed to bone powder (arrows). Small cracks in this region may be preparation artifacts (Toluidine blue, original magnification ×100). (e) TPS surface in graft: Bone resorption activity at the interface is evident through an osteoclast in the Howship's lacuna (arrow) (Toluidine blue, original magnification ×400)

(a) Microtextured surface in graft: General overview shows a clear demarcation with different bony trabeculae between the most apical grafted area (graft) and the more coronal native bone (basal) (Toluidine blue, original magnification ×8). (b) Microtextured surface in graft: The trabeculae in the regenerated area are randomly arranged and their thickness and connection are determined by the shape and size of the embedded graft particles (Toluidine blue, original magnification ×25). (c) Microtextured surface in graft: Magnification of the regenerated area shows a mix of bone (arrows), graft particles (G), and graft powder (P) contacting the implant surface (Toluidine blue, original magnification ×50). (d) Microtextured surface in graft: Magnification of the apical interface shows a mix of graft powder and particle fragments without cells immersed in a mineralized matrix (Toluidine blue, original magnification ×50)

(a) Oxidized surface in graft: Differences and limits between the basal bone (B) and the grafted region (R) were easily visible (asterisks). Bone structure was quite dense, but a high percentage of the mineralized tissues contained graft particles (Toluidine blue, basic fuchsin, original magnification ×8). (b) Oxidized surface in graft: Magnification of the regenerated tissues showed that many peri-implant trabeculae (B) contained embedded graft particles (G) and were quite thick and well connected. Most of the graft particles (G) were embedded in the newly formed bone and were not found in the marrow spaces (M) (Toluidine blue, basic fuchsin, original magnification ×25). (c) Oxidized surface in graft: Magnification of the previous case. The surfaces of the graft particles (G) exposed to the marrow spaces were covered by multinuclear giant cells (asterisk) and showed the typical white unstainable layer (B = bone, V = vessel, arrows = osteoclast) (Toluidine blue, original magnification ×200). (d) Oxidized surface in graft: The thickness of the titanium-oxide coating (arrows) well integrated to the newly formed bone (B) is clearly evident. The newly formed bone is composed of woven bone with small or large particles of the graft (G), with few medullary spaces containing vessels (V) (Toluidine blue, original magnification ×200). (e) Oxidized surface in graft: Small debris of the titanium-oxide coating was detected in macrophages a few microns from the implant surface without signs of acute or chronic inflammatory cell infiltrate. The black powder visible inside the macrophages represents small particles of the coating. The rectangle represents the area magnified in the following picture (NB = new bone, arrow = macrophages) (Toluidine blue, original magnification ×100). (f) Oxidized surface in graft: High-power magnification of the previous picture. Macrophages (M) engulfed by granules of TiUnite coating are visible in the peri-implant marrow spaces. (B = bone, O = osteocyte, arrows = bone-marrow interface, asterisk = mastcell) (Toluidine blue, original magnification ×1000)

and 5. Figure 4. (a) Sandblasted and acid-etched surface in graft: General overview of the SLA implant. The graft area is limited to the apical side of the peri-implant bone. The bone structure is poor with thin and brittle trabeculae (Toluidine blue, basic fuchsin, original magnification ×8). (b) Sandblasted and acid-etched surface in graft: Magnification of the previous implant is in rectangle A. A very thin layer of newly formed bone was adapted on the sandblasted and acid-etched surface, particularly at the level of the threads (Toluidine blue, basic fuchsin, original magnification ×25). (c) Sandblasted and acid-etched surface in graft: Magnification of the previous implant is in rectangle B corresponding to the sinus grafted region. The bone (B) is denser at this level and the connectivity is more pronounced. Many different-sized graft particles (G) are embedded in the newly formed bone trabeculae (M = marrow tissues, IT = implant thread) (Toluidine blue, basic fuchsin, original magnification ×25). Figure 5. (a) Hydroxyapatite (HA) surface in graft: General overview of the HA-coated implant. The graft area is spread all around the peri-implant bone. The bone structure is dense but the trabeculae are inconsistently arranged (Toluidine blue, basic fuchsin, original magnification ×8). (b) HA surface in graft: Magnification of the HA-coated implant. The coating (arrows) was clearly visible with a well-preserved structure and thickness and a high percentage of osseointegration (B = bone; G = graft particles) (Toluidine blue, basic fuchsin, original magnification ×25). (c) HA surface in graft: Magnification of the apical part of the HA-coated implant. The most apical threads were surrounded by many graft particles and a small amount of vital bone. However, the HA-coating (arrows) was layered by a continuous bony trabeculum (B = bone, G = graft particles) (Toluidine blue, basic fuchsin, original magnification ×25)

and 7. Figure 6. (a) Hydroxyapatite (HA) surface in native bone: The HA coating (arrow) on the implant (I) shows well-preserved structure and thickness. Bone (B) is present as on the tips of the threads and in the interthread regions (Toluidine blue, basic fuchsin, original magnification ×8). (b) HA surface in native bone: Thin bone trabeculae (B) are present close to the implant (I) surface (arrow) (Toluidine blue, basic fuchsin, original magnification ×25). Figure 7. (a) Acid-etched surface in native bone: Overview of the Osseotite surface in basal bone shows that bone (B) extends from the second thread of the implant (I) on the right side but is first present (B) at the fourth and fifth thread on the left side (Toluidine blue, basic fuchsin, original magnification ×8). (b) Acid-etched surface in native bone: Mature lamellar bone (B) is visible in intimate contact with an implant (I) thread (T) (Toluidine blue, basic fuchsin, original magnification ×25)