【摘要】　目的　从临床和实验研究两方面探讨深龋乳牙冠髓病理学状况及导致冠髓病变的原因。方法　随机选择面深龋乳磨牙45颗，行活髓切断术，光镜下观察其冠髓病理改变；用需氧、厌氧培养技术研究其髓腔内细菌；用扫描电镜观察窝洞底部牙本质小管中细菌的种类和分布特征。结果　77.8%的冠髓有不同程度的慢性炎症或慢性牙髓炎急性发作；94.9%的髓腔中有需、厌氧菌混合感染；洞底牙本质小管中有球菌和杆菌侵入，球菌均位于小管内，而杆菌通过破坏管壁侵润至管间牙本质。结论　深龋乳牙髓腔内已有需、厌氧菌侵入，杆菌对牙本质小管有更强的破坏力，2/3以上冠髓已为慢性炎症。

The study of histopathology and bacteriology of coronal pulp tissue in deciduous teeth with deep dentin caries

WANG Xiaoli, YANG Pishan, YU Ying, et al.

　　(Department of Pedodontics, Stomatology Hospital of Shandong Medical University, Jinan 250012, China)

　　【Abstract】　Objective　To study the status of coronal pulp of deciduous teeth with deep caries and causes of pulpal histopathological changes. Methods　45 deciduous molars with occlusal deep caries were selected at random. The patients did not receive any antibiotic for one month. The coronal pulpal histopathology was observed with optical microscopic technique. The bacteria in pulp chamber were cultured by the ways of aerobic and anaerobic culture technique. The dentinal tubular structures and bacteria within the tubules of cavity basal part dentin were studied with scanning electron microscopic technique. Results　Coronal pulp tissue of 77.8% of deciduous teeth with deep caries showed chronic inflammation to various degrees or chronic pulpitis with acute attack. There were aerobic and anaerobic mixed infection in pulp chambers of 94.9% deciduous teeth with deep caries. It was found that coccus and bacillus invaded into dentinal tubules of cavity basal part. Coccus located inside tubules with intact tubular walls, while tubular walls were destroyed the bacillus was present. Conclusion　 There are aerobic and anaerobic mixed infection in pulp chamber of deciduous teeth with deep caries. The coronal pulp tissue shows chronic inflammation to various extent in over 2/3 deciduous teeth with deep caries. Bacillus has stronger destructive power to dental tubules.

　　【Key words】　Tooth, deciduous；　 Dental caries；　 Pathology，oral；　 Bacteriology

　　现阶段我国儿童口腔工作仍以防治龋齿为重点［1，2］。乳牙深龋的临床治疗中常常出现充填后疼痛和牙髓炎症反应，导致治疗失败。这可能与乳牙深龋时牙髓组织学改变有关。为此，我们对临床诊断为深龋的乳磨牙的冠髓病理、髓腔内及窝洞底部牙本质小管中细菌种类和分布特征进行研究，为选择最佳的乳牙深龋治疗方案提供依据。

　　材料和方法

　　一、病例选择及标本收集

　　1．病例选择：从山东医科大学附属口腔医院儿童牙科门诊中随机选择近1个月内未使用过抗生素的3～11岁龋病患儿32例，按临床诊断标准诊断为面深龋的乳磨牙共45颗。

　　2．标本收集：常规局麻，对45颗患牙行活髓切断术。①用消毒高速钻头开髓，用高压灭菌微量取样器插入开髓孔注入灭菌NS 10 μl，抽吸10 μl，即刻无菌条件下送细菌培养。②完整揭去髓室顶，将其放入蒸馏水中待做扫描电镜观察。③用锐利刮匙切除全部冠髓组织，将其置于10%甲醛液中送检。