A five-year evaluation of implants placed in extraction sockets

The aim of this study is to examine extraction socket implant longevity and peri-implant conditions longitudinally and to compare the outcome with implants placed in intact alveolar bone sites (nonextraction sites) after a time period in function of five years or more. We hypothesize that implants placed into fresh extraction sockets have a long-term rate of success similar to that of conventionally placed implants. Eleven extraction socket implants in eight patients with a follow-up of at least five years were included in this report. The implants were loaded with either single-tooth replacements or three-to-four-unit fixed partial dentures after healing times of four to six months. Intraoral radiographs of the 11 implants were obtained immediately after surgery and upon recall five to seven years after surgery. In addition, the following clinical parameters were evaluated at each implant site five to seven years postsurgery: plaque indices (PT), bleeding indices (BI), probing depths, attachment level (AL), and distance from implant shoulder to mucosal margin (DIM). As a control, 11 implants from a previous long-term study of nonsubmerged implants placed into intact alveolar bone sites by the same clinician were matched by implant location, sex, and age. Initial and long-term follow-up radiographs of the experimental and control groups were scanned into a computer. A computer program designed for radiographic implant analysis was utilized to examine the changes in radiographic bone levels over time in the two groups. After a period of five to seven years, the mean bone loss for the immediate implant group was 0.167 mm, while that of the control group was 0.460 mm. An unpaired t-test resulted in a P value = 0.0563, indicating that the mean change in bone levels between the two groups is not statistically significant. In addition, clinical evaluation parameters (PI, BI, AL, DIM) revealed no significant difference between the two groups. Therefore, it can be stated that in this study the long-term success rate for extraction socket implants is similar to that of conventionally placed implants.