Marginal bone levels at Brånemark system implants used for single tooth restoration. The influence of implant design and anatomical region.

In this retrospective study of Brånemark system oral implants, 75 consecutive patients were treated with 84 implants for single-tooth replacement from 1988 to 1993. Two implants were lost and not replaced: the first one before the abutment connection, the latter during the first year in function. The cumulative failure rate reached 2.4% during the 5-year period. Seventy-one percent of the implants were located in the incisor/canine region of both jaws. Twenty-six per cent of the implants were inserted in special presurgical or surgical conditions. The mean annual bone loss as scored on radiograph, was 0.8 mm during the first year and 0.1 mm the following years. Different implant designs were used, a more pronounced bone loss was observed for the conical implant. The present data shows that the cumulative failure rate for single Brånemark implants and radiographic bone loss is similar to that found around implants used for the treatment of complete and partial edentulism.