【作者】 谢方方；

【导师】 何克新；

【作者基本信息】 广西医科大学 ， 口腔内科学， 2004， 硕士

【摘要】 目的：通过扫描电镜和光学显微镜在原位上观察未治疗及治疗失败的无症状感染根管中微生物的形态、分布和相对位置来初步了解微生物在这二者中的定植模式及其异同，并初步探讨微生物与牙髓治疗失败的关系，为临床上治疗失败根管的再治疗提供参考。 材料与方法：新鲜拔除的18颗无症状并伴有根尖部病损的离体牙牙根，其中未治疗牙根6颗、根管治疗失败和塑化治疗失败的牙根各6颗。2.5％戊二醛固定24小时后，将牙根在颊舌向沿牙齿长轴劈开成两半，一半用于扫描电镜观察；另一半脱钙后切片，分别用HE染色(观察细胞)和Brown & Brenn染色(观察微生物)后在光学显微镜下观察。 结果：(1)所有未治疗组被检根管均被微生物感染，在根管壁的大部分区域均能找到稠密的微生物，不同根管和同一根管的不同部位，微生物的构成存在差异，常由多种细菌(球菌、多种杆菌)构成致密复杂的生物膜。细菌侵入牙本质小管的深度通常在100μm以内，某些样本中可侵入约300μm深。根尖周组织中以慢性炎细胞浸润为主，未见有微生物。(2)根管治疗失败组中3例在根管中发现有细菌，主要为球菌，1例仅发现真菌。微生物形态较单一，菌落分布均散在。细菌可侵入牙本质小管中，侵入深度在100μm以内。5例样本根尖周组织有慢性炎细胞浸润，1例为疤痕组织，均未见微生物。(3)塑化治疗失败组中2例在根管中发现有细菌，主要为球菌，2例仅发现真菌。微生物形态较单一，菌落分布均散在。细菌可侵入牙本质小管中，侵入深度在100μm以内。4例样本根尖周组织有慢性炎细胞浸润，2例为疤痕组织，均未见微生物。 结论：(1)未治疗组中根管微生物的定植模式为多种细菌混合感染，微生物形成稠密而结构复杂的生物膜。(2)塑化治疗失败组和根管治疗失败组根管中微生物的量明显减少。其定植模式为：形态上单一的细菌构成孤岛状的小菌落，以分散的形式存在，球菌为最常见的微生物。(3)根尖周组织的炎症可能与微生物在根管中的持续存在有关，根尖周组织以疤痕形式愈合的情况可能与其根管为无菌状态有关。(4)塑化治疗失败根管中，单一真菌感染出现的几率较高。(5)根尖周组织中没有发现有微生物存在的证据。更多还原

【Abstract】 Objective: To study the morphology, distribution and relative position of microorganisms in situ in untreated and fail-treated root canal using scanning electron microscopy and light microscopy.Methods: 18 recently extracted roots were studied. They were divided into three groups. The roots on group 1 were untreated. Group 2 were failed in root canal therapy. Group 3 were failed in resinfying therapy. Each group had six roots. All cases demonstrated evidence of periapical radiolucencies. The root was split into two halves along the gena-lingua axis. One half was studied under scanning electron microscopy. The other half was observed under light microscopy for histology and microorganisms.Results: (1) Microorganisms were found in all untreated roots. However, the patterns of microbial colonization were different in individual roots and varied in different areas of the same root. The microbial colonization in root canals was made up of cocci and/or bacilli that often blended together in a community. The depth of the invasion of bacteria in dental tube was about 100 um. However, in some roots we did find that it could be up to 300um. Infiltration of chronic inflammation cell was discovered in periapical tissues with no microorganism observed. (2) In the group that failed in the root canal therapy, bacteria, mostly cocci were found in 3 cases and fungus was found in one case solely. The invasion of bateria was within 100um. Colonies can be found dispersedly in dental tubes with unitary morphology. Chronic inflammation cell infiltration was discovered in the perapical tissue of 5 specimens. Scar tissue was found in one specimens. No microorganism was found in the perapical tissue. (3) In the group that failed in resinfying therapy, cocci were found mostly in 2 cases and fugi were found solely in the other 2 cases. The invasion of bateria was within 100um. Colonies can be found dispersedly in dental tubes with unitary morphology. Chronic inflammation cell infiltration was discovered in the perapical tissue of 3 specimens, and scartissue was found in 2 specimens. No microorganism was found in the perapicaltissue.Conclusions: (1) Severe infection occurs in untreated root canals. The pattern ofmicrobial colonization is characterized as climax community. (2) The pattern ofmicrobial colonization in failed-treated root canals of root canal therapy andresinfying therapy dramatically differ from that of the untreated, which can becharacterized as unitary morphology, smaller dispersed islet-like colonies. (3) Thecontinuant existence of microorganisms is due to the failure of root canal therapyand resinfying therapy. (4) In the asymptomatic infected root canals of failuretreatments, the coccus is the mostly common microorganism. (5) The eukaryoticmicroorganism is related to the chronicle continuant infection and its reoccurrence.(6) It is possible that little microorganisms exist in the perapical tissue ofasymptomatic infected root canals.更多还原