Oral implants in combination with bone grafts: A 3-year retrospective multicenter study using the Brånemark implant system

Abstract

A retrospective, multicenter, Scandinavian study of bone grafting of alveolar processes of severely atrophic jaws in combination with implant insertion was conducted with 150 patients. Five different grafting techniques were assessed: local or full onlay; inlay; combination of onlay/inlay grafts; and LeFort I osteotomies. The majority of the patients were treated using a one-stage approach (n=125) and all had autogenous bone grafts. A total of 781 Brånemark implants were inserted, of which 624 were placed in bone grafts and alveolar bone. Twenty-five patients (17%) dropped out during the follow-up period of three years. Within the remaining patients, 77% of the inserted implants (n=516) were still in function at the end of the follow-up period. A further ten implants were kept mucosa-covered, resulting in an overall implant survival rate of around 80%. Onlays, inlays and LeFort I osteotomies showed almost the same success rates (76-84%), whereas the onlay/inlay technique gave rise to less favourable results (60%). Most of the observed losses (n=131) took place during healing and the first year of loading. More implants were lost when they were inserted simultaneously with the grafting (23%) than when they were placed in a second stage (10%). The latter technique was used mainly in combination with local onlay grafting (16/25). The failure percentage for implants inserted in non-grafted bone (11%) was lower than for those inserted in bone grafts and alveolar bone (25%). The surviving implants of treated and followed patients served, in 88% of the cases (n=110), to support fixed bridges or overdentures, albeit, in some instances (n=23), after additional implant placement. In only 15 patients was it necessary to fall back on conventional removable prostheses or fixed partial bridges.