Anorganic bovine bone ( ABB ) vs. autologous bone ( AB ) plus ABB in maxillary sinus grafting. A prospective non‐randomized clinical and histomorphometrical trial

Objectives This investigation focused on histological characteristics and 5‐year implant survival after sinus floor augmentation with anorganic bovine bone ( ABB , Bio‐Oss ® ) and ABB plus autologous bone ( AB ) with a ratio of 1/1. Material and methods Nineteen consecutive patients with bony atrophy of the posterior edentulous maxilla and a vertical bone height ≤4 mm were prospectively included in this study. In the first surgical stage, the maxillary sinus was non‐randomized either augmented with ABB alone ( n  = 12) or a 1/1 mixture of ABB and AB ( n  = 7). After a mean healing period of 167 days, biopsies were harvested in the region of the grafted sinus with a trephine burr and implants were placed simultaneously, ABB n  = 18 and ABB  +  AB n  = 12. The samples were microradiographically and histomorphometrically analyzed judging the newly formed bone (bone volume, BV ), residual bone substitute material volume ( BSMV ), and intertrabecular volume (soft tissue volume, ITV ) in the region of the augmented maxillary sinus. Implant survival was retrospectively evaluated from patient's records. Results No significant difference in residual bone substitute material ( BSMV ) in the ABB group (31.21 ± 7.74%) and the group with the mixture of ABB and AB (28.41 ± 8.43%) was histomorphologically determined. Concerning the de novo bone formation, also both groups showed statistically insignificant outcomes; ABB 26.02 ± 5.23% and ABB  +  AB 27.50 ± 6.31%. In all cases, implants were installed in the augmented sites with sufficient primary stability. After a mean time in function of 5 years and 2 months, implant survival was 93.75% in the ABB and 92.86% in the ABB  +  AB group with no statistically significant differences. Conclusion The usage of ABB plus AB to a 1/1 ratio leads to an amount of newly formed bone comparable with the solitary use of ABB after grafting of the maxillary sinus. Considering that ABB is a non‐resorbable bone substitute, it can be hypothesized that this leads to stable bone over time and long‐term implant success. Importantly, in the sole use of ABB , bone grafting and therefore donor site morbidities can be avoided.