In vivo behavior of a custom-made 3D synthetic bone substitute in sinus augmentation procedure in sheep.

In this study, the in vivo behavior of a custom-made 3D synthetic bone substitute used as scaffold for sinus augmentation procedures in an animal model was evaluated. The scaffold was a calcium phosphate ceramic fabricated by the direct rapid prototyping technique dispense-plotting. The geometrical and chemical properties of the scaffold were firstly analyzed through light and electron scanning microscope, helium picnometer and semi-quantitative X-ray diffraction measurements. Then, six sheep underwent monolateral sinus augmentation with the fabricated scaffolds. The animals were euthanized after healing periods of 45 and 90 days, and block sections including the grafted area were obtained. Bone samples were subjected to micro-CT, morphological and histomorphometric analyses. A complete integration of the scaffold was reported, with abundant deposition of newly formed bone tissue within the biomaterial pores. Moreover, initial foci of bone remodelling were mainly localized at the periphery of the implanted area after 45 days, while continuous bridges of mature lamellar bone were recorded in 90 days specimens, supporting the hypothesis that bone regeneration proceeds from the periphery to the center of the sinus cavity