ONE-STEP SURGICAL PLACEMENT OF BRANEMARK IMPLANTS - A PROSPECTIVE MULTICENTER CLINICAL-STUDY

This prospective longitudinal multicenter study evaluated the clinical outcomes after placement and restoration of one-step Branemark implan ts into the maxillae and mandibles of completely and partially edentul ous patients. Six surgical treatment centers participated in this stud y, in which 135 implants were placed into 63 adult patients. All impla nts were stable after placement. The majority of implants were placed into type B bone with minimal jaw resorption and type 2 bone quality A fter implant placement, standard transmucosal healing abutments were f irmly placed. The average amount of time between implant placement and prosthetic abutment connection was 170 days in the maxillae and 147 d ays in the mandibles. To evaluate crestal bone changes caused by impla nt placement, a periodontal probe was used to measure midbuccally from the top of the implant cylinder to the alveolar crest; in 29 patients , 54 midbuccal bone crest sites were remeasured following prosthetic a butment connection. Crestal bone changes in mandibles and maxillae wer e statistically and clinically insignificant. Six implants were lost p rior to loading and one implant has not been restored. No implants or restorations were lost after loading. At 1 year, the implant success r ate was 95.6%. Mesiodistal radiographic measurements from 34 patients were averaged, and changes from prosthetic abutment connection to, on average, 12 months follow-up were compared. The radiographs, which wer e digitalized, measured from the bottom of the implant cylinder to the most coronal bone in contact with implant thread. For mandibular impl ants, the mean radiographic bone level at prosthetic abutment connecti on was 1.07 mm; after loading, it was 1.35 mm. For maxillary implants, the mean radiographic bone height at prosthetic abutment connection w as 1.16 mm; after loading, it was 1.36 mm. These changes were not stat istically significant. The 1-year outcomes from this patient series in dicate that one-step Branemark implants provide excellent clinical res ults when placed in patients with good bone quality and quantity.