大鼠慢性牙周炎模型中牙龈卟啉单胞菌的检测

Detection of Porphyromonas gingivalis in SD rats with chronic periodontitis

目的检测慢性牙周炎模型大鼠颈总动脉血管组织中牙龈卟啉单胞菌的含量，探讨其与慢性牙周炎相关的可能机制。方法将42只SD大鼠平分为6组，每组7只。A组：正常对照组，不施加任何干预措施；B1~B5组为实验组，按照同一建模形式建成牙周炎的动物模型，再按照不同的牙周干预措施具体分组：B1组，不施加干预措施；B2组，施加机械治疗干预；B3组，行全身药物治疗；B4组，对患牙施加拔除措施；B5组，拔除患牙后应用抗生素3 d。实验结束后处死动物，分别截取各组大鼠右侧颈总动脉分叉处的血管组织，采用16S rRNA聚合酶链反应法半定量检测牙龈卟啉单胞菌的含量。结果在所有大鼠中，均检出牙龈卟啉单胞菌；B1~B5组牙龈卟啉单胞菌的相对含量较A组显著升高，差异有统计学意义（P〈0.01）；B1组的牙龈卟啉单胞菌相对含量最高，显著高于B4、B5组，差异有统计学意义（P〈0.05），与B5组的统计学差异更为明显（P〈0.01）。结论牙龈卟啉单胞菌作为牙周常驻菌可能会入侵并定植于血管内皮细胞，导致相关功能障碍；尽早拔除重度松动的患牙可以更彻底地清除牙龈卟啉单胞菌，同时于拔牙后加用抗生素能够较为明显地降低牙龈卟啉单胞菌在血管内皮细胞的定植。

Objective To detect Porphyromonas gingivalis（P.gingivalis） in the carotid artery of rats with chronic periodontitis and to explore the possible relationship between P.gingivalis and chronic periodontitis. Methods Forty-two SD rats were randomly divided into six groups： Group A（control group）, group B 1 （non-intervention group）, group B2（scaling and root planning group）, group B3（systemic antibiotics group）, group B4（tooth extraction group）, and group B5（tooth extraction with antibiotics for 3 d）. Each group accepted the corresponding measures and periodontal interventions to establish the animal model. After the death of experimental animals, P.gingivalis was semi-quantitatively detected in the right carotid artery tissue by 16S rRNA polymerase chain reaction. Results P.gingivalis was detected in all groups. The relative quantity of P.gingivalis significantly increased in groups B 1 to B5 compared with that in group A（P〈0.01）. The relative quantity of P.gingivalis was the highest in group B1, showing a significant difference with B4 and B5（P〈0.05）. A statistically significant difference in the relative quantity of P.gingivalis was also found between B 1 and B5（P〈0.01）. Conclusion P.gingivalis is a periodontal resident pathogen that can invade endothelial cells, leading to associative function disorders. In addition, extraction of loose teeth without delay eliminates P.gingivalis. The intake of antibiotics after tooth extraction decreases the adhesion of P.gingivalis to endothelial cells.