目的：探究不同炎症状态对比格犬（Beagle犬）年轻恒牙牙髓干细胞增殖及成骨能力的影响，为炎症牙髓干细胞的应用提供理论依据。方法：选取Beagle犬年轻恒前磨牙14颗，通过开髓后牙髓暴露的方法建立牙髓炎模型。对照组于开髓后立即拔髓，实验组分别于术后2周和6周拔出牙髓组织。HE染色确定牙髓炎症程度，提取不同炎症状态下牙髓组织RNA，实时荧光定量PCR（real-time PCR）检测炎症因子肿瘤坏死因子α（tumor necrosis factorα，TNF-α）、白细胞介素（interleukin，IL）家族IL-1β、IL-6、IL-10的表达。酶消化法分离培养正常牙髓干细胞（dental pulp stem cell，DPSC）和炎症牙髓干细胞（inflammatory DPSC，IDPSC），细胞计数试剂盒（cell counting kit-8，CCK-8）法测定其生长曲线，并对其进行成骨分化诱导，茜素红染色，real-time PCR检测成骨相关基因骨涎蛋白（bone sialoprotein，BSP）、碱性磷酸酶（alkaline phosphatase，ALP）、牙本质涎磷蛋白（dentin sialophosphoprotein，DSPP）的表达情况。结果：开髓暴露2周和6周后，根管内仍有存活的牙髓组织，伴有不同程度的炎症细胞浸润，6周组牙髓中炎症因子高表达。各组牙髓均可分离培养出牙髓干细胞，IDPSC的增殖能力强于DPSC。经成骨诱导后实验组细胞BSP、ALP和DSPP的表达均显著高于DPSC（P<0.01），但6周组表达显著低于2周组（P<0.01）。结论：Beagle犬年轻恒牙早期牙髓炎症状态下，牙髓干细胞的增殖和成骨分化能力均有所增强。

Objective：To compare the proliferation and osteoblastic differentiation of dental pulp stem cell (DPSC) isolated from normal and inflamed pulps of different degrees in Beagle immature premolars, and provide evidence for the use of inflammatory DPSC (IDPSC). Methods: This study evaluated 14 Beagle’s young premolars (21 roots). In the experiment group, irreversible pulpitis was induced by pulp exposure and the inflamed pulps were extracted 2 weeks and 6 weeks after the pulp chamber opening.For the control group, normal pulps were extracted immediately after the exposure. HE staining and real-time PCR were performed to confirm the inflammation. The cells were isolated from the inflamed and normal pulps (IDPSC and DPSC). Cell proliferation and osteoblastic differentiation potentials of the two cells were compared. Results: Inflammation cells infiltration was observed in the inflamed pulps by HE staining. The expression of inflammatory factor was much higher in the 6 week inflamed pulp. IDPSC had higher potential of cell proliferation and osteoblastic differentiation potentials. Furthermore, the osteoblastic differentiation potentials of IDPSC from 2 week inflamed pulp were higher than those from 6 week inflamed pulp. Conclusion: The potential of cell proliferation and osteoblastic differentiation of DPSC was enhanced at early stage of irreversible pulpitis, and reduced at late stage in Beagle immature premolars.