Immediate Dental Implants and Bone Graft

Dental implants were initiated in 1922 by Branemark, who and associates described the relationship between titanium implant and bone which termed osteointegration, defined as the direct structural and functional connection between living bone and the surface of an implant (Albrektsson et al., 1981). Immediate implant placement, defined as the placement of dental implant immediately into fresh extraction socket site after tooth extraction , has been considered a predictable and acceptable procedure (Schwartz et al., 2000). In addition, with immediate implant placement there is minimal use of surgical drills because the socket is already found except for slight increase of the socket length in an attempt to improve primary stability (Barzilay et al., 1991). The decreased surgical trauma of immediate placement type will decrease the risk of bone necrosis and permit bone remodeling process to occur, i.e. the healing period is rapid and allows the woven bone to be transformed into lamellar bone (Hansson et al., 1983, Ericsson, 2000). Moreover, the natural socket is rich in periodontal cells and matrix, which makes the healing faster and more predictable. Based on the review article by Penarrocha et al., 2004 and the time elapsed between tooth extraction and implantation, the following classification has been established relating the receptor zone to the required therapeutic approach. (a) Immediate implantation, when the remnant bone sufficient to ensure primary stability of the implant, which is inserted in the course of surgical extraction of the tooth to be, replaced (primary immediate implants). (b) Recent implantation, when approximately 6-8 weeks have elapsed from extraction to implantation – a time during which the soft tissues heal, allowing adequate mucogingival covering of the alveolus (secondary immediate implants). (c) Delayed implantation, when the receptor zone is not optimum for either immediate or recent implantation. Bone promotion first carried out with bone grafts and/or barrier membranes, followed approximately six months later by implant positioning (delayed implants). (d) Mature implantation, when over nine months have elapsed from extraction to implantation. Mature bone is found in such situations.