光动力疗法联合EDTA应用于根管消毒的实验研究

发布时间：2018-05-21 21:11

本文选题：光动力疗法 + 单态氧　；参考：《天津医科大学》2014年硕士论文

【摘要】：目的：根管消毒是根管治疗中的关键步骤,其目的是彻底清除根管内的感染源、预防再感染,目前根管消毒还未达到非常理想的程度,因此有必要寻找一种更有效、彻底的根管消毒方法。光动力疗法(photodynamic therapy, PDT)是光、光敏剂和氧共同参与,可产生强氧化性的单态氧杀伤致病微生物的一种新疗法,它具有抗菌作用强、抗菌谱广、作用迅速、安全性好且不会产生耐药性等优点。EDTA(乙二胺四乙酸二钠)作为根管冲洗剂具有渗透性强、能去除根管内玷污层等优点。本研究结合光动力疗法与EDTA的优点将二者联合应用,首先对根管内感染的主要致病菌悬液进行作用,筛选出二者联合时光动力疗法的最佳效应参数,然后在体外建立根管感染模型,探究二者联合进行根管消毒的效果,期望找到一种更加安全、有效的根管消毒方法。方法： 1.将粪肠球菌标准株(E. faecalis ATCC29212)复苏厌氧培养48h,调整浓度制备成1×109CFU/mL的菌悬液。 2.菌悬液经17%EDTA处理后,用波长532nm半导体激光器分别照射30s、60s、90s、120s与不同浓度光敏剂血卟啉单甲醚(hematoporphyrin monomethylether, HMME)20μg/ml、40μg/ml、60μg/ml进行作用,选择出EDTA预处理后光动力疗法的最佳参数。 3.收集因正畸拔除的离体前磨牙75颗,采用冠向下法进行根管预备,将粪肠球菌在根管内连续培养21天建立粪肠球菌感染模型。 4.将感染模型随机均分为5组,A组：PDT处理组；B组：EDTA处理组；C组：PDT联合EDTA处理组；D组：NaClO阳性对照组；E组：生理盐水阴性对照组。各组处理前、处理后分别用纸尖在根管内取样,进行平板菌落计数,统计分析,评价PDT联合EDTA进行根管消毒的即刻效果。 5.进行回复实验,在处理后的根管内注满无菌液体培养基,培养7天后用纸尖取样,统计检出细菌的根管个数,统计分析,评价PDT联合EDTA进行根管消毒的远期效果。 6.扫描电子显微镜观察处理后的根管内壁形态,进一步验证PDT联EDTA进行根管消毒的效果。结果： 1.在本实验条件下,粪肠球菌菌悬液经17%EDTA预处理后光动力疗法的最佳效应参数为：光敏剂HMME浓度40μg/ml；波长532nm、功率密度0.14W/cm2半导体激光器连续照射90s。 2.PDT联合17%EDTA对感染根管内粪肠球菌杀伤结果显示,与生理盐水阴性对照组相比,PDT处理组、EDTA处理组、PDT联合EDTA处理组、NaC1O阳性对照组根管内粪肠球菌数目均显著减少(P0.05)；单独PDT组杀菌率为89.77%,与NaClO阳性对照组相比无显著差异(P0.05)；PDT联合EDTA组杀菌率达到100%,明显高于单独PDT处理组、单独EDTA处理组、NaClO阳性对照组和生理盐水阴性对照组(P0.05)。 3.回复实验结果显示,生理盐水阴性对照组与单独EDTA处理组中全部根管都检出了细菌,有菌根管比例达100%；单独PDT处理组和NaClO阳性对照组检出细菌根管个数分别为12个和13个,有菌根管比例分别为80.00%和86.67%；PDT联合EDTA组检出细菌根管数仅为4个,有菌根管比例仅为26.67%,明显少于单独PDT处理组、单独EDTA处理组、NaClO阳性对照组和生理盐水阴性对照组(P0.05)。 4.扫描电子显微镜图像显示：PDT联合EDTA组根管内壁无玷污层及细菌附着,全部牙本质小管口呈开放状态；牙本质小管通畅,无玷污栓阻塞,内壁光滑无细菌附着。结论： 1.光动力疗法联合EDTA对体外游离的粪肠球菌有很好的杀灭作用,粪肠球菌菌悬液经17%EDTA预处理后光动力疗法的最佳效应参数为：光敏剂HMME浓度40μg/ml；波长532nm、功率密度0.14W/cm2半导体激光器连续照射90s。 2.光动力疗法联合EDTA进行根管消毒,不但能去除根管内玷污层,而且还能有效杀灭根管内粪肠球菌,并且有较好的远期效果,是一种高效的根管消毒方法,有望为提高临床根管消毒效率提供一条新途径。
[Abstract]:Objective:
Root canal disinfection is a key step in root canal therapy. The aim is to thoroughly remove the source of infection in the root canal and prevent reinfection. The root canal disinfection has not reached a very ideal level. Therefore, it is necessary to find a more effective and thorough root canal disinfection method. Photodynamic therapy (PDT) is a common reference to light, photosensitizer and oxygen. It can produce strong oxidizing mono oxygen to kill pathogenic microorganisms. It has the advantages of strong antibacterial effect, broad antibacterial spectrum, rapid action, good safety and no resistance to resistance..EDTA (ethylenediamine tetra acetic acid two) has the advantages of strong permeability and can remove the stain layer in root canal. The advantages of dynamic therapy and EDTA are combined with the two people. First, the main pathogenic bacteria suspension in the root canal infection is used, and the best effect parameters of the two combined time dynamic therapy are screened out, then the root canal infection model is established in vitro, and the effect of the two joint root canal elimination is explored, hoping to find a safer and more effective method. Method of root canal disinfection.
1. the E. faecalis ATCC29212 strain of Enterococcus faecium was resuscitation in anaerobic culture 48h and adjusted to 1 * 109CFU/mL suspension.
After the 2. bacteria suspension was treated by 17%EDTA, the wavelength 532nm semiconductor laser was used to irradiate 30s, 60s, 90s, 120s and the 20 micron (hematoporphyrin monomethylether, HMME) monomethyl ether (hematoporphyrin monomethylether, HMME) with different concentration of photosensitizer (hematoporphyrin monomethylether, HMME), and 60 micron g/ml. The best parameters of the photodynamic therapy after pretreatment were selected.
3. a total of 75 anterior molars extracted from orthodontic were collected, and the root canal preparation was carried out by the crown method. The Enterococcus faecalis was cultured in the root canal for 21 days to establish a model of Enterococcus faecalis infection.
4. group of infection models were randomly divided into 5 groups, group A: PDT treatment group; group B: EDTA treatment group; C group: PDT combined with EDTA treatment group; D group: NaClO positive control group; E group: normal saline negative control group. Before treatment, each group was treated with paper tip in root canal to carry out flat plate count, statistical analysis and evaluation PDT combined EDTA. The immediate effect of sterilizing the root canal.
5. the recovery experiment was carried out. The root canal was filled with the culture medium of sterile liquid in the root canal after treatment. After 7 days of culture, the sample was sampled with paper tip. The number of root canal of bacteria was detected statistically. The long-term effect of PDT combined with EDTA for root canal disinfection was evaluated.
6. scanning electron microscope (SEM) was used to observe the morphology of the root canal, and further verify the effect of root canal disinfection with PDT EDTA.
1. under the conditions of this experiment, the best effect parameters of photodynamic therapy for Enterococcus faecalis suspension after 17%EDTA preconditioning are: the concentration of photosensitizer HMME is 40 g/ml, the wavelength is 532nm, and the power density 0.14W/cm2 semiconductor laser irradiate 90s. continuously.
The killing results of 2.PDT combined with 17%EDTA in infected root canal Enterococcus showed that compared with the negative control group, the number of Enterococcus faecalis in the NaC1O positive control group decreased significantly (P0.05) in the PDT treatment group, the EDTA treatment group and the PDT combined EDTA treatment group, and the single PDT group was 89.77%, and there was no significant difference compared with the NaClO positive control group. In group EDTA, the bactericidal rate of PDT combined with EDTA was 100%, which was significantly higher than that of the single PDT treatment group, EDTA treatment group, NaClO positive control group and normal saline negative control group (P0.05).
3. the results of the 3. recovery test showed that all the root canals in the normal saline negative control group and the single EDTA treatment group were detected bacteria, and the proportion of the mycorrhizal tube was 100%. The number of bacterial root canal in the single PDT treatment group and the NaClO positive control group were 12 and 13 respectively, and the proportion of the mycorrhizal tube was 80% and 86.67%; the PDT combined with the EDTA group detected the bacteria. The root canal number was only 4, and the proportion of mycorrhizal tube was only 26.67%, obviously less than the single PDT treatment group, the single EDTA treatment group, the NaClO positive control group and the normal saline negative control group (P0.05).
4. scanning electron microscope images showed that the inner wall of PDT combined with EDTA group had no tarnished layer and bacteria attachment, all dentinal tubules were open, the dentinal tubules were unobstructed, no tarnishing embolus was blocked, and the inner wall was smooth and no bacteria attached.
Conclusion:
1. photodynamic therapy combined with EDTA has a good killing effect on the free Enterococcus faecalis in vitro. The best effect parameters of photodynamic therapy after 17%EDTA pretreatment are as follows: the HMME concentration of photosensitizer is 40 g/ml, the wavelength is 532nm, and the power density 0.14W/cm2 semiconductor laser is continuously irradiated with 90s.
2. photodynamic therapy combined with EDTA for root canal disinfection can not only remove the smear layer in the root canal, but also effectively kill the Enterococcus faecalis in the root canal, and has a good long-term effect. It is an efficient method of root canal disinfection. It is expected to provide a new way to improve the efficiency of clinical root canal disinfection.
【学位授予单位】：天津医科大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R781.05

【参考文献】