Sinus floor augmentation with autogenous bone vs. a bovine-derived xenograft - a 5-year retrospective study

The long-term outcome after sinus augmentation with autogenous bone or a bovine xenograft (Bio-Oss(®)) was assessed in 47 patients. Inclusion criterion was a vertical dimension of the maxilla of <4 mm. After a functional loading period of 60 months, implant survival and reduction in the augmentation height were compared between the two groups evaluated.

Sinus augmentation was performed using mandibular bone grafts or Bio-Oss(®). In the autogenous bone group, 70 implants were placed in 23 patients, while in the Bio-Oss(®) group, 24 patients received 98 implants. Fisher's exact test and equivalence testing were used to compare implant survival rates.

The overall survival rate of the implants was 95.8% 5 years after implant insertion. In the autogenous bone group, the implants had a survival rate of 97.1%, while in the Bio-Oss(®) group, 94.9% of the implants survived. The difference was not statistically significant (P > 0.05); both treatments are equivalent (confidence interval 90%) for the equivalence interval [-0.1; 0.1]. 43.5% of the cases showed no reduction in the augmentation height 5 years after implant insertion, when augmentation was performed with autogenous bone, while in the Bio-Oss(®) group, no resorption was found in 50% of the augmented areas. Up to 25% reduction in augmentation height was found in 47.8% in the autogenous and in 45.8% in the Bio-Oss(®) group. In 8.7% of all cases in the autogenous bone group and in 4.2 % in the Bio-Oss(®) group, up to 50% of the augmented height was resorbed.

After a 5 years evaluation period, Bio-Oss(®) as material for the indication maxillary sinus augmentation shows to be equivalent to autogenous bone grafting.