中文摘要：

目的：探讨根尖孔的大小对根管内牙髓组织再生量的作用。方法：收集临床上因正畸需要拔除的前磨牙,制备成6mm长的根管段,根据根尖孔直径分成5组,即A组（0.3mm）、B组（0.5mm）、C组（0.7mm）、D组（0.9mm）、E组（1.1mm）,每组12个,根管段内植入复合血管内皮生长因子（VEGF）的多肽水凝胶胶原支架。选取30只6周龄裸鼠,于裸鼠背部皮下左右两侧各植入1个根管段,8周后取材进行组织学评价。结果：根管段管腔中再生的组织为疏松的结缔组织。A组、B组、C组、D组和E组根管内新生组织面积与管腔面积比值的中位数和四分位间距分别为13.3%（6.3%,19.0%）、15.0%（3.6%,27.7%）、5.93%（1.7%,30.8%）、9.87%（6.2%,18.2%）和9.73%（1.5%,27.3%）,不同组别根管中再生组织量比较差异无统计学意义（P〉0.05）。结论：根尖孔大小对根管段中再生组织量没有明显的影响。

英文摘要：

Objective：To explore the effect of the width of apical foramen on the amount of newly formed tissues in pulp regeneration. Methods： 60 extracted premolars in orthodontic treatment were collected and trimmed into 6 mm long root carnals. Root carnals were divided into 5 groups according to the diameter of apical foramen., group A （0.3 mm）, group B （0.5 mm）, group C （0.7 mm）, group D （0. 9 mm） and group E （1.1 mm）, with 12 root carnals in each group. All root carnals were filled with vascular endothelial growth factor （VEGF） combined peptide hydrogel scaffold and implanted subcutaneously on both side of nude mice. The implants were taken out 8 weeks later and were made into tissue slices for observation. Results： The median value of neonatal loose connective tissue area to root canal area ratio in group A, B, C,D and E were 13.3% （6.3%, 19.0%）, 15.0% （3.6%, 27.7%）, 5.93% （1.7%, 30.8%）, 9.87% （6.2%, 18. 2%） and 9.73%（1.5%,27.3%）. There was no statistical significance in the amount of regenerated tissue in the root canal among groups. Conclusion. The diameter of apical foramen had no significant effect on neonatal tissues grown into the pulp chamber in pulp regeneration.