Efeito do uso de enxerto de dentina associada a células-tronco mesenquimais na formação óssea pós-exodontia : estudo in vivo

Abstract

In terms of safety, durability and esthetics, dental rehabilitation after tooth extraction is a challenge in Dentistry. Implants represent a great advance in this field, nevertheless, to maintain or retrieve adequate bone volume and alveolar structure to support the implant and soft tissues is still a challenge. Bone grafts, autogenous, allogeneic, xenogeneic, or alloplastic materials have limitations such as additional morbidity, high financial cost, risk of disease transmission and ethical/religious barriers. Autogenous dentin from extracted teeth has physical, chemical, and biological properties of an excelent bone graft; however, it is routinely discarded. The present work aimed to evaluate the effect of dentin matrix alone or combined with mesenchymal stem cells (MSC) on post-extraction alveolar bone repair. Sixty Wistar rats were subjected to extraction of first and second right upper molars with subsequent osteotomy and allocated into groups according to the graft inserted: (1) Gelita-Spon®; (2) Bio-Oss®; (3) Dentin; (4) MSC; (5) Dentin/MSC; (6) Control. At 35 days of postoperative period, the animals were euthanized, and maxillae dissected to be analyzed by means of hematoxylin and eosin (H&E) staining, immunohistochemical (IHC) analysis (collagen type I, osteopontin, VEGF and osteocalcin), micro-computed tomography (micro-CT) and scanning electron microscopy (SEM). Serum levels of calcium and phosphorus were quantified. The Bio-Oss group showed significantly less bone than Gelita-Spon and Dentin/MSC; no other significant differences were seen in H&E analysis. The Bio-Oss group showed significantly higher expression of collagen type I compared to the Dentin and Dentin/MSC groups and also higher osteocalcin expression than the Dentin/MSC group. Although not statistically significant, there was a tendency of higher expression of osteopontin in the MSC, Dentin and Dentin/MSC groups and higher VEGF in the MSC group. On micro-CT analysis, the Bio-Oss and the Dentin/MSC groups exhibited greater bone volume than the Control. Serum calcium and phosphorus levels did not significantly differ between the groups. SEM analysis depicted particles of Bio-Oss and dentin in the respective groups, as well as significant cellularity in the MSC group. Conclusion: Autogenous non-demineralized dentin is an alternative for alveolar bone grafting, which can be improved by combination with MSC.