The negatively charged TiUnite surface attracts blood proteins and inactive platelets immediately after implant insertion. Simultaneously, fibrils from the fibrin meshwork become visible.
The platelets begin to swell and form pseudopodia. By releasing adenosine diphosphate (ADP), they get sticky and clump together, closing the injured blood vessels at the wound edges to stop the bleeding.
The newly formed fibrin matrix allows the blood to clot. Activated platelets become embedded in the matrix and release granules full of enzymes and growth factors needed for wound healing and bone formation.
Blood cells, activated platelets and fibrin form a blood clot that adheres to the moderately rough TiUnite surface. It is crucial for contact osteogenesis that the blood clot remains attached to the surface.
Neutrophils and, later, macrophages, remove the blood clot during the first two days of wound healing. Osteogenic cells stream to the TiUnite surface and migrate to the front of the forming bone. Here, they turn into osteoblasts.
Newly formed bone spreads over the osteoconductive TiUnite surface and forms a thin band of woven bone deposited directly on and along the surface. This thin bone layer will grow by further bone apposition and turn into lamellar bone.
Bone forming osteoblasts attach to the TiUnite surface and cover the orifices of the open pores. They start to secrete the collagen matrix of woven bone directly into the pores and move away from the surface. This forms the collagenous bone matrix which will eventually mineralize.
Osteoconductive surface for new bone formation
Newly formed bone crosses the gap between local bone and implant by distance osteogenesis. When the bone reaches the TiUnite surface, it spreads over it by contact osteogenesis, characterized by woven bone deposited directly on and along the surface.
Transmitted and polarized light shows early (four weeks) and ongoing (six months) bone formation by contact osteogenesis and final osseointegration.
Grooves added to the threads of the implant promote initial bone formation. Bone grows in a spiral-like fashion along the grooves before spreading laterally over the entire TiUnite surface.
During drilling bone fragments are generated and accumulate in the osteotomy, especially in the apical region. In this area, they serve as nuclei for bone formation by guiding osteogenic cells through the wound and towards the TiUnite surface.