COMPARISON OF BRANEMARK FIXTURE INTEGRATION AND SHORT-TERM SURVIVAL USING ONE-STAGE OR 2-STAGE SURGERY IN COMPLETELY AND PARTIALLY EDENTULOUS MANDIBLES

The aim of this prospective study was to compare the clinical integrat ion and survival of Branemark fixtures when using the conventional 2-s tage surgical procedure to a 1-stage surgical approach in completely a nd partially edentulous mandibles. A total of 85 patients were consecu tively treated for partial (n=35) or complete (n=50) mandibular edentu lousness. Fixtures removed because of mobility, pain or infection were counted as failures. The first 10 patients of each group were selecte d for radiographical analysis of crestal bone changes 1 year after pro sthesis insertion. In 33 patients with edentulous mandibles, 170 fixtu res were placed in a 1-stage approach. In this group, 4 fixtures (2.4% ) were lost prior to prosthetic restoration. Seventeen edentulous pati ents received a total of 70 fixtures in a 2-stage procedure. Out of th ese, 5 fixtures (7.1%) were lost at abutment connection. In 17 partial ly edentulous patients, 41 fixtures were inserted in a 1-stage approac h. Two fixtures (5%) were lost in this group. Finally, 18 partially ed entulous patients received a total of 49 fixtures in a 2-stage procedu re. Out of these, 6 fixtures (12%) were lost at abutment connection. I n total 313 of the 330 installed mandibular implants were loaded betwe en 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 year s (59 implants). Statistical analysis (Chi square test) revealed no di fference in fixture survival between the treatment modalities, Radiogr aphical 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-stag e surgical approach with Branemark fixtures may be as predictable as t he conventional 2-stage procedure.