Immediate loaded dental implants: comparison between fixtures inserted in postextractive and healed bone sites.

In the last two decades, several investigators have reported immediate placement of dental implants into extraction sockets achieving excellent results with a two-stage surgical procedure. Recently, immediate loading (IL) has become an emerging technique because it has been documented to be a successful and time-saving procedure. Regarding the possibility of immediate/early loading of implants placed in fresh extraction sockets, few reports are available. In addition, they are based on limited series with short follow up. Thus, we decided to perform a retrospective study on a large series of postextractive IL implants. From January 1995 to October 2004, 416 IL fixtures were placed immediately after extraction and 658 IL fixtures in healed sites. The mean follow up is 3 years. Multiple implant systems were used. Because only eight of 1,074 implants were lost (i.e., survival rate, 99.3%) and no statistical differences were detected among the studied variables, no or reduced marginal bone loss was considered as an indicator of success rate to evaluate the effect of several host-, surgery-, and implant-related factors. A general linear model was then performed to detect those variables statistically associated with marginal bone loss. Only eight of 1,074 implants were lost (i.e., survival rate, 99.3%) and no differences were detected among the studied variables. On the contrary, the general linear model showed that younger age (cutoff, 55 years) and harder bone are related to a lower delta insertion abutment junction (or marginal bone loss) and thus a better outcome. We demonstrated that postextractive IL implants have a high survival rate and success rate that are similar to those reported in previous studies of two-stage procedures or in IL implants inserted in healed bone. Poor bone quality and older age correlate with a slight higher bone resorption.