Dissertation committee:
Καρατζάς Θεόδωρος, Αναπληρωτής Καθηγητής (Επιβλέπων), Ιατρική Σχολή, ΕΚΠΑ
Περρέα Δέσποινα, Ομότιμη Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Αγρογιάννης Γιώργος, Αναπληρωτής Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Κόντζογλου Κωνσταντίνος, Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Δοντά Ισμήνη, Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Δημητρούλης Δημήτριος, Αναπληρωτής Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Κύκαλος Στυλιανός, Επίκουρος Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Summary:
Regeneration of large jaw bone defects still remains a clinical challenge. To avoid incomplete bone repair, bone grafts have been advocated to support healing process.
The aim of this study was to evaluate in vivo the development of newly formed bone as well as to observe at histologic level the processes that take place during the incorporation of materials, using 3 commercially available bone grafting products in mono-cortical calvaria porcine defects. In details, we evaluated: a. a synthetic bone substitute (Calc-i-oss classic, Sunstar Guidor, Switzerland), b. a human bone derivative (Demokritos, National Center for Scientific Research tissue bank, Athens, Greece), c. a bovine derived xenograft (Bio-Oss, Geistlich Pharma AG, Wolhusen, Switzerland), as well as d. an empty bone deficit, in surgically prepared bone cavities.
Animals were randomized in 2 groups, sacrificed at 8 and 12 weeks, and the tissues collected were evaluated qualitatively by histologic examination and quantitatively regarding the production of new bone through histomorphometry.
The results of our research are summarized below: 1. The b-TCP graft exhibited more intense production of new bone compared to the bovine and the human graft at 8 and 12 weeks, 2. While b-TCP was found to produce less bone production compared to the empty bone cavity at 8 weeks, in the relatively more mature phase of the healing process at 12 weeks showed greater bone tissue growth, 3. Bovine and human transplant material showed less bone production compared to the empty cavity at 8 and 12 weeks, 4. According to histologic evaluation, b-TCP showed the most intense rate of absorption - dissolution in the period between 8 and 12 weeks compared to bovine and human graft, where their particles, especially those of the bovine substitute, appeared relatively intact, without remarkable decomposition ability, 5. The empty cavity exhibited intense bone production at both 8 and 12 weeks, occupying the 1st and 2nd place respectively, according to the histomorphometric analysis, which allows us to suggest that the given bone defect cannot be classified as critical in this particular porcine animal model, 6. It is particularly evident that the aforementioned bone regeneration materials have different characteristics, which affects their degradation pattern as well as bone regeneration, and 7. All materials exhibited osteoconductive properties, with the absence of inflammatory response and foreign body reaction, confirming their satisfactory biocompatibility.
Keywords:
Alveolar bone grafting, Bone substitutes, Bone regeneration, Bone replacement material
