This study aimed to evaluate the use of human dental pulp stem cells (hDPSCs) in non-critical-sized mandibular bone defects in rats. hDPSCs from permanent teeth were isolated and engrafted in mandibular bone defects in rats for 7, 14, and 28 days; bone defects without cells formed the control group. Samples were evaluated by scanning electron microscopy (SEM), light microscopy (hematoxylin and eosin staining), and the regeneration area was measured by the Image J program. Before surgery procedures, the human dental pulp cells were characterized as dental pulp stem cells: fusiform morphology, plastic-adherent; expression of CD105, CD73, and CD90; lack of expression of CD45 and CD34, and differentiated into osteoblasts, adipocytes, and chondroblasts. The results indicated that within 7 days the control group presented a pronounced bone formation when compared with the treated group (p < 0.05). After 14 days, the treated group showed an increase in bone formation, but with no statistical difference among the groups (p > 0.05). In the final evaluated period there was no difference between the control group and the treated group (p > 0.05). There was a significant difference between 7 and 14 days (p < 0.05) and between 7 and 28 days (p < 0.05) in the treated group. In conclusion, there is no evidence that the use of hDPSCs in the conditions of this study could improve bone formation in non-critical-sized mandibular bone defects.

中文翻译：

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大鼠下颌骨缺损中的人牙髓干细胞

本研究旨在评估人牙髓干细胞 (hDPSCs) 在大鼠非临界尺寸下颌骨缺损中的应用。来自恒牙的 hDPSCs 被分离并植入大鼠的下颌骨缺损中 7、14 和 28 天；没有细胞的骨缺损形成对照组。通过扫描电子显微镜（SEM）、光学显微镜（苏木精和伊红染色）评估样品，并通过Image J程序测量再生面积。手术前，人牙髓细胞被表征为牙髓干细胞：梭形形态，可塑性粘附；CD105、CD73和CD90的表达；CD45 和 CD34 缺乏表达，并分化为成骨细胞、脂肪细胞和成软骨细胞。结果表明，与治疗组相比，对照组在 7 天内呈现明显的骨形成（p < 0.05）。14天后，治疗组骨形成增加，但组间无统计学差异（p>0.05）。在最终评估期间，对照组和治疗组之间没有差异（p > 0.05）。治疗组在 7 到 14 天（p < 0.05）和 7 到 28 天（p < 0.05）之间存在显着差异。总之，没有证据表明在本研究条件下使用 hDPSC 可以改善非临界尺寸下颌骨缺损的骨形成。但组间无统计学差异（p > 0.05）。在最终评估期间，对照组和治疗组之间没有差异（p > 0.05）。治疗组在 7 到 14 天（p < 0.05）和 7 到 28 天（p < 0.05）之间存在显着差异。总之，没有证据表明在本研究条件下使用 hDPSC 可以改善非临界尺寸下颌骨缺损的骨形成。但组间无统计学差异（p > 0.05）。在最终评估期间，对照组和治疗组之间没有差异（p > 0.05）。治疗组在 7 到 14 天（p < 0.05）和 7 到 28 天（p < 0.05）之间存在显着差异。总之，没有证据表明在本研究条件下使用 hDPSC 可以改善非临界尺寸下颌骨缺损的骨形成。