Bone grafts and dental implants in the reconstruction of the severely atrophied, edentulous maxilla

Sammanfattning: In two prospective, clinical studies the stability of implants and prosthetic constructions were evaluated after three years of loading. In the first study, the implant and the bridge stability of 39 patients with 1-stage bone grafts, were compared to a reference-group of 37 patients who did not need bone grafts. In the second study, 40 patients were randomised to have either 1-stage sinus inlay bloc grafts or 2-stage sinus inlay particulated grafts. Implant success in Paper 1, was 75.3% in the study group and 93.1% in the reference group. In Paper 2 implant survival in the 1-stage group was 77.7% and 86.5% in the 2-stage group. Bruxism and post-operative complications, such as unexpected pain, dehiscence and infection were found to be associated with the later loss of implants. The volumes of onlay block and inlay particulated bone grafts, after 6 months as evaluated by computed tomography showed the decrease of 49.5% and 47% respectively, although there was a wide range in both groups. Using of cutting torque measurements during the placement of implants in grafted and non-grafted jaw bone, showed a significant inverse correlation to the commonly used clinical estimation of jaw bone quality, acc. to Lekholm & Zarb. Significantly lower torque values were recorded in grafted regions when compared to non-grafted. It was shown that autogenous bone grafts and implants to the edentulous maxilla, after early high failure rates, showed stable and predictable results after three years. Bruxism was found to be significantly associated with implant failures and initially reduced biomechanical properties was seen in the grafted bone.