The basics: osseointegration
The aim of the surgical procedure for implant placement is to prepare, in an atraumatic manner, an intraosseous bed into which a dental implant is inserted. Following soft tissue elevation, a channel is drilled into the cortical and spongy bone and the dental implant (screw type titanium device), slightly wider than the channel, is slowly inserted within the “implant bed” (the channel) surgically created.
The compression of the bone surrounding the implant reduces the peripheral vasculature, and the lack of an adequate blood supply leads to a non-vital tissue at the bone/implant interface. The inflammatory response to the surgical injury aims to remove the damaged tissues and to initiate the healing process leading to osseointegration, i.e. the direct connection between newly formed bone and the metal device.
The initial stability of the interface between the implant and the mineralized bone is a critical factor to initiate the osseointegration process. The primary stability of the dental implant is often achieved at the cortical bone level. In the cortical compartment at the implant neck, the non-vital lamellar bone is first resorbed before new bone formation occurs onto the implant surface.
At the implant body, in the cancellous compartment, the wound healing includes the following phases (Berglundh et al., 2003; Abrahamsson et al., 2004).
1 Clot Formation
The blood fills the space between the threads of the implant. Erythrocytes, neutrophils, and macrophages are trapped in a fibrin network. The fibrin clot is replaced by granulation tissue. Mesenchymal cells and blood vessels proliferate in the new granulation tissue, which is rich in collagen fibers (Fig.