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Background: Various techniques for tissue engineering have been introduced to aid the regeneration of defective or lost bone tissue. The aim of this study was to compare the in vivo bone-forming potential of bone marrow mesenchymal stem cells (BM-MSCs) and platelet-rich fibrin (PRF) on induced bone defects in rats’ tibiae. Methods: In total, one defect of 3-mm diameter was created in each tibia of 36 Wistar male rats. There were two groups: group A, left tibia bone defects that received PRF; and group B, right tibia bone defects of the same animal that received BM-MSCs loaded on a chitosan scaffold. Subsequently, Scanning electron microscope/energy-dispersive X-ray (SEM/EDX) analyses was performed at 3 and 10 days, and 3 weeks post‑implantation and following euthanasia; (n=12). Results: The EDX analysis performed for each group and time point revealed a significant increase in the mean calcium and phosphorous weight percentage in the BM-MSC-treated group relative to the PRF-treated group at all-time intervals (P < 0.05). Moreover, the mean calcium and phosphorus weight percentage increased as time progressed since the surgical intervention in the PRF-treated and BM-MSCs groups (P < 0.05). Conclusions: In the present study, both BM-MSCs and PRF were capable of healing osseous defects induced in a rat tibial model. Yet, BM-MSCs promoted more adequate healing, with higher mean calcium and phosphorous weight percentages than PRF at all-time points, and showed greater integration into the surrounding tissues than PRF.

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Objective: Multiple etiological factors contribute to the process of erosion and destruction of enamel. Among which, carbonated soft beverages and energy drinks are the most aggressive extrinsic causes. The consumption of milk whether bovine or plant based highly contributes to the remineralization process.Design: Thirty five freshly extracted sound human maxillary first premolars were used and randomly divided into the following groups; Group I (Control group): included 5 teeth immersed in distilled water. Group II (Power Horse group): 15 teeth were immersed in 330ml of the drink. Group III (Cornelius group): 15 teeth were immersed in 330ml of the energy drink. After 10 days, the teeth were further randomly divided as follows (5 teeth each); Group IV (Power Horse +Lactose free milk), Group V (Power Horse +Almond milk), Group VI (Cornelius +Lactose free milk) and Group VII (Cornelius +Almond milk). Teeth of groups IV-VII were placed in both types of milk for 5 days where the milk was changed every 2 hrs. The remaining teeth from groups II and III (5 teeth each) were kept in distilled water. At the end of the experimental period, the teeth were prepared for SEM examination, EDX and statistical analyses.Results: SEM examination showed that surface erosion was more aggressive in Power Horse group (II) when compared to Cornelius group (III). Furthermore, the results revealed better remineralizing effect in groups IV and VI (lactose free treated) rather than those treated with almond milk (groups V and VII). EDX results presented statistically significant decrease in Ca and P wt % in group II compared to group III. Statistically significant increase in Ca and P wt % in group IV in relation to group V and similarly, significant increase in group VI compared to group VII were also detected. Conclusion:Energy drinks produce erosive defects of varying intensity on the enamel surface of human teeth. The intake of remineralizing agents; such as milk, immediately following every meal containing acidic diet is mandatory to reverse the demineralization process.