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A total of 264 implants was placed in 143 patients using different immediate or delayed-immediate implant placement techniques in 12 different centers participating in a prospective multicenter study. The reason for tooth extraction was evaluated; bone quality and quantity were classified; socket depths were registered; and data on implant type, size, and position were collected. One hundred thirty-nine suprastructures were placed on 228 implants in 126 patients. A follow-up evaluation was done on 125 patients after 1 year of loading and on 107 patients after 3 years of loading. Clinical parameters (bleeding or not bleeding, pocket depth, and implant mobility) were evaluated after 1 and 3 years, and the marginal bone level after 1 year of loading was measured on radiographs. Clinical comparisons were performed to evaluate implant loss in relation to implant type, size, position, bone quality and quantity, socket depth, reason for tooth extraction, and placement method. In addition, life table analysis was done for cumulative implant survival rates. There was no clinical difference with respect to socket depth or when comparing the different placement methods. A higher failure rate was found for short implants in the posterior region of the maxilla and when periodontitis was cited as a reason for tooth extraction. Mean marginal bone resorption from the time of loading to the 1-year follow-up was 0.8 mm in the maxilla and 0.5 mm in the mandible. Over a period of 3 years, the implant survival rate was 92.4% in the maxilla and 94.7% in the mandible. [ABSTRACT FROM AUTHOR]

Background: As a complement to the earlier reported 3-year results from a prospective multicenter study of immediate and delayed placement of implants into fresh extraction sockets, the 5-year results are reported., Purpose: The purpose of this 5-year report was to evaluate the immediate and long-term success of implants placed into fresh extraction sockets, with respect to implant size and type, bone quality and quantity, implant position, initial socket depth, and reason for tooth extraction., Materials and Methods: This paper presents the 5-year results of the original 12 centers that participated with 143 consecutively included patients. A total of 264 implants were placed either immediately after tooth extraction or after a short soft-tissue healing time (3-5 weeks). The patients were divided into five subgroups, depending on the type of insertion method used., Results: The outcome demonstrated that the cumulative implant survival rate after 5 years of loading has not changed and remains 92.4% in the maxilla and 94.7% in the mandible. No difference in failure rates can be seen between the groups when relating the failures to insertion method., Conclusion: This prospective study demonstrated that placing Brånemark implants into fresh extraction sites can be successful over a period of 5 years of loading. One of the outcomes of the study shows that there is a clinical correlation between implant failure and periodontitis as a reason for tooth extraction, even if it is difficult to give it a casual association. It can be hypothesized that periodontitis affected tissues might have a negative local influence because of the presence of infrabony defects that could possibly increase the gap between bone and implant or jeopardize achievement of primary stability.

This paper demonstrates that an intact extraction socket is not necessary for the successful integration of a titanium implant fixture. Several case reports are used to describe the immediate placement of fixtures into compromised sockets, some in conjunction with bone grafting and/or guided tissue regeneration techniques to enhance the surgical result. Advantages of immediate implant placement are threefold: (1) treatment time is significantly reduced; (2) ridge contour can be preserved; and (3) it is possible to place the fixture in a more ideal axial position, thus enhancing fabrication, esthetics, and biomechanics of the subsequent restoration.

In recent years, much emphasis has been placed on the refinement and enhancement of prosthetic components and techniques in implant dentistry, while the surgical protocol has remained fairly constant. The evolution of the concept of the immediate placement of fixtures into extraction sites, along with the related concept of guided tissue regeneration, is a major advancement in the surgical field. It provides significant benefit to both patient and clinician in terms of the reduced treatment time and an enhanced prognosis related to biomechanics and aesthetics.

The results of this study summarized in the Table 1 indicate that both allogenic and xenogenic dentin matrix stimulated sufficient new bone formation to bridge the gap between the two cut ends of a bone (rat fibula). Allogenic bone grafts appeared to be successful in restoring resected bone more often than did xenografts.