Histomorphometric outcome following sinus floor augmentation with allogeneic adipose tissue-derived stem cells. A randomized controlled experimental study

The aim of this pre-clinical study was to test the hypothesis of no difference in histomorphometric outcome following sinus floor augmentation (SFA) with allogeneic adipose tissue-derived stem cells (AASCs) seeded on deproteinized bovine bone mineral (DBBM) (test) compared with excipient on DBBM (control). Eighteen minipigs were allocated into three groups of six animals and euthanised after one month (T1), two months (T2), and four months (T3). The sinuses of each animal were randomly assigned to either test or control with identical graft volume. Percentage of newly formed bone (NFB), non-mineralized tissue, residual DBBM, and bone-to-implant contact (BIC) were estimated by histomorphometric analysis in a randomly selected region of interest and summarized as mean percentage with 95% confidence interval. Test group, mean percentage of NFB and BIC was 8.8 and 19.5 (T1), 17.7 and 23.2 (T2), 37.1 and 30.4 (T3). Control group, corresponding values were 8.9 and 13.9 (T1), 18.7 and 23.3 (T2), 36.8 and 36.6 (T3). There were no significant differences in NFB or BIC at T1 (P = 0.964; 0.551), T2 (P = 0.927; 0.992), and T3 (P = 0.971; 0.557) between test or control. Percentage of NFB was significantly higher at T3 compared with T1, in test (P = 0.001) and control (P = 0.004), while no significant difference in BIC was disclosed between T1, T2, and T3, in test and control, respectively. In conclusion, adding AASCs to DBBM seem not to improve NFB or BIC compared with DBBM alone in conjunction with SFA.