AUTOLOGOUS STROMAL STEM CELLS (SSC) IN MAXILLARY SINUS AUGMENTATION: AN EXPERIMENTAL STUDY IN MINIPIG

Objective: The aim of the proposed study was to evaluate whether the combination of SSC with natural hydroxyapatite (HA) would improve the amount and the speed of bone formation and the bone to implant contact in maxillary sinus augmentation procedure. Material & Methods: Six adult mini-pigs were included in the study. The mini-pigs were housed individually at the institute animal facility 4 weeks before surgery. Bone marrow cells were harvested from adult mini-pig 3 weeks before the operation. The cells isolated by centrifugation were expanded in CO2 incubators to the number required for the procedure. Prior to surgery the animals were premedicated and receive anesthesia. Minipig received bilateral maxillary sinus augmentation. Through an extraoral approach, a window 1×1 cm was cut into the bony facial sinus wall, and the antral membrane was elevated from the sinus floor. The SSC/ HA was placed into the right maxillary sinus, while HA alone was placed in the left maxillary sinus as a control. At the same time a titanium implant was inserted in each sinus from a laterocaudal direction. Radiography were taken every 2 weeks. Mini-pig were euthanized at two time points after 8 and after 12 weeks. The maxillae were removed and a block-session of each sinus was fixed to be histologically and histomorphometrically studied. Results: The use of SSC seemed to increase the quantity of newly-formed bone. Conclusions: The addition of stromal stem cells could, probably, be a useful tool to improve the results in sinus augmentation procedures.