Biphasic Calcium Phosphate Biomaterials: Stem Cell-Derived Osteoinduction or In Vivo Osteoconduction? Novel Insights in Maxillary Sinus Augmentation by Advanced Imaging

Abstract

Maxillary sinus augmentation is often necessary prior to implantology procedure, in particular in cases of atrophic posterior maxilla. In this context, bone substitute biomaterials made of biphasic calcium phosphates, produced by three-dimensional additive manufacturing were shown to be highly biocompatible with an efficient osteoconductivity, especially when combined with cell-based tissue engineering. Thus, in the present research, osteoinduction and osteoconduction properties of biphasic calcium-phosphate constructs made by direct rapid prototyping and engineered with ovine-derived amniotic epithelial cells or amniotic fluid cells were evaluated. More in details, this preclinical study was performed using adult sheep targeted to receive scaffold alone (CTR), oAFSMC, or oAEC engineered constructs. The grafted sinuses were explanted at 90 days and a cross-linked experimental approach based on Synchrotron Radiation microCT and histology analysis was performed on the complete set of samples. The study, performed taking into account the distance from native surrounding bone, demonstrated that no significant differences occurred in bone regeneration between oAEC-, oAFMSC-cultured, and Ctr samples and that there was a predominant action of the osteoconduction versus the stem cells osteo-induction. Indeed, it was proven that the newly formed bone amount and distribution decreased from the side of contact scaffold/native bone toward the bulk of the scaffold itself, with almost constant values of morphometric descriptors in volumes more than 1 mm from the border.

Three-Dimensional Plotted Calcium Phosphate Scaffolds for Bone Defect Augmentation—A New Method for Regeneration

“…However, when analyzing the bone ingrowth into the scaffolds, a pronounced bone ingrowth was obvious at the contact area between the scaffold and the host bone. This finding is in line with the results of Iezzi et al who observed a higher integration and a pronounced new bone formation into a three-dimensional printed scaffold consisting of hydroxyapatite and tricalcium phosphate at the contact area to the host bone in a sheep model [ 35 , 36 ]. This observation is explainable by the ingrowths of blood vessels which are delivering growths factors enabling cell migration into the scaffold.…”

Microbiota of the sheep's maxillary sinus as an experimental model

“…;Iezzi et al (2021);Sheftel et al. (2019);Mastrangelo et al (2019)), its anatomical proximity to the cortex, and volumes similar to those of homes as described byAlsafy et al (2021) and later byMasoudifard et al (2022) in their tomographic analysis giving a detailed description of the anatomy of the head of this experimental model.…”