Implants placed in immediate function in periodontally compromised sites: A five-year retrospective and one-year prospective study

Statement of problem. Placing implants in periodontally compromised sites is generally considered a risk factor. Good results have been reported when rehabilitating partial or complete edentulous sites in patients with a history of periodontitis. However, there is a need for more documentation of this treatment modality. Purpose. The purpose of this study was to report, retrospectively, on the placement of implants in periodontally compromised areas of the maxilla and mandible without a prior healing period and in immediate function. This study also presents a prospective preliminary 1-year report using a standardized clinical protocol, including a regenerative surgical procedure, control of the inflammatory response, a maintenance protocol, and use of an implant with an oxidized surface. Material and methods. The clinical study encompassed 184 consecutively included patients with 433 Implants (165 with a machined surface and 268 with an oxidized surface) placed in immediate function (140 in the maxilla and 293 in the mandible) supporting 218 Fixed prostheses. Two groups were defined: the Retrospective group (using an unstandardized surgical technique and a majority of machined surface implants) with a retrospective approach and the Prospective group (using standardized surgical and maintenance protocols and oxidized surface implants) with a prospective approach. The 2 groups were evaluated for implant survival, clinical implant stability, bone resorption, absence of radiolucent areas around implants on the radiographs, and patient-reported function of the implants. Definitive prostheses were placed 6 months after the surgery. The data was analyzed using descriptive statistics. Results. Thirteen implants were lost in 9 patients, providing a cumulative survival rate of 91% at 5 years for the Retrospective group. In the Prospective group, a 100% cumulative survival rate was recorded after 1 year. The average bone resorption (SD) was 1.2 mm (0.9 mm) and 1.1 mm (1.1 mm) after the first year for the Retrospective and Prospective groups, respectively, and 1.7 mm (1.0 mm) for the Retrospective group after the fifth year of function. Conclusions. The cumulative survival rate of 91% at 5 years for the Retrospective group is low compared to protocols for noncompromised situations, but the use of a standardized protocol together with oxidized surface implants seems to improve the treatment outcome and bring the survival rate to levels comparable to noncompromised situations.