Comparison of Brånemark fixture integration and short‐term survival using one‐stage or two‐stage surgery in completely and partially edentulous mandibles

The aim of this prospective study was to compare the clinical integration and survival of Brånemark fixtures when using the conventional 2-stage surgical procedure to 1-stage surgical approach in completely and partially edentulous mandibles. A total of 85 patients were consecutively treated for partial (n = 35) or complete (n = 50) mandibular edentulousness. Fixtures removed because of mobility, pain or infection were counted as failures. The first 10 patients of each group were selected for radiographical analysis of crestal bone changes 1 year after prosthesis insertion. In 33 patients with edentulous mandibles, 170 fixtures were placed in a 1-stage approach. In this group, 4 fixtures (2.4%) were lost prior to prosthetic restoration. Seventeen edentulous patients received a total of 70 fixtures in a 2-stage procedure. Out of these, 5 fixtures (7.1%) were lost at abutment connection. In 17 partially edentulous patients, 41 fixtures were inserted in a 1-stage approach. Two fixtures (5%) were lost in this group. Finally, 18 partially edentulous patients received a total of 49 fixtures in a 2-stage procedure. Out of these, 6 fixtures (12%) were lost at abutment connection. In total 313 of the 330 installed mandibular implants were loaded between 6 and 12 months (94.8% success). No further losses occurred in the implants functioning at least 1 year (267 implants) or at least 2 years (59 implants). Statistical analysis (Chi square test) revealed no difference in fixture survival between the treatment modalities. Radiographical analysis after 1 year of functional loading showed the typical bone resorption changes up to the most coronal implant thread in both modalities. Although this study pertains to relatively early loading of 2 years, the results seem to indicate that in the mandible a 1-stage surgical approach with Brånemark fixtures may be as predictable as the conventional 2-stage procedure.